Proceedings of the Standing Senate Committee on
Social Affairs, Science and Technology
Issue 41 - Evidence - May 30, 2013
OTTAWA, Thursday, May 30, 2103
The Standing Senate Committee on Social Affairs, Science and Technology met this day, at 10:28 a.m., to examine the subject matter of Bill C-314, An Act respecting the awareness of screening among women with dense breast tissue.
Senator Kelvin Kenneth Ogilvie (Chair) in the chair.
[English]
The Chair: Honourable senators, our second witness is not here at the moment, but with your agreement we will begin and welcome her to the meeting as soon as she does arrive. We were scheduling her presentation to be second in any event.
[Translation]
Welcome to the Standing Senate Committee on Social Affairs, Science and Technology.
[English]
My name is Kelvin Ogilvie, a senator from Nova Scotia and chair of the committee. I would now invite my colleagues to introduce themselves.
Senator Seidman: Judith Seidman from Montreal, Quebec.
Senator Martin: Yonah Martin, British Columbia.
Senator Seth: Asha Seth, Ontario.
Senator Eaton: Nicky Eaton, Ontario.
Senator Enverga: Tobias Enverga from Ontario.
Senator Cordy: I am Jane Cordy; I am a senator from Nova Scotia.
Senator Dyck: I am Lillian Dyck, a senator from Saskatchewan.
Senator Eggleton: Art Eggleton, senator from Toronto and deputy chair of this committee.
The Chair: Thank you, honourable senators.
I will welcome the witnesses as I introduce them to make their presentation. I remind colleagues that we have a very tight meeting. We have two sessions. The first is scheduled to end in exactly one hour. The second will end one hour following that. I want to remind you that we will stay as a committee for approximately half an hour or less following the end of this meeting to deal with instructions to the analysts. That was on the agenda as was sent out. Is that agreed?
Hon. Senators: Agreed.
The Chair: Today we are continuing our study of the subject matter of Bill C-314, and we are very pleased today to welcome, from the Canadian Association of Radiologists, Dr. Jacques Lévesque, President; and Dr. Jean Seely, Working Group Member, dealing with CAR Practice Guidelines Breast Imaging.
Welcome. I understand that Dr. Lévesque will be making the presentation.
[Translation]
Dr. Jacques Lévesque, President, Canadian Association of Radiologists: Mr. Chair, ladies and gentlemen, committee members, the Canadian Association of Radiologists (CAR) is the national specialty society for approximately 2,500 radiologists. As the physician experts in medical imaging, we are dedicated to promoting patient safety in medical imaging.
We are pleased that the government views breast health as a topic requiring a national approach. In doing so, it gives us the opportunity to be here to provide comment on the Breast Density Awareness Act.
The CAR has operated an accreditation program for screening and diagnostic mammography centres for 20 years. The program ensures that only qualified medical personnel perform and interpret mammograms and that dedicated mammography equipment remains optimally operational.
The CAR also produces practice guidelines for healthcare providers. Its CAR Practice Guidelines and Technical Standards for Breast Imaging and Intervention will be released shortly. We believe that annual screening with mammography beginning at age 40 has been scientifically proven to significantly decrease breast cancer mortality.
Accurate and accessible information is extremely important for patients and their doctors. The CAR Standard for Communication of Diagnostic Imaging Findings states that the radiologist report, which transmits the imaging information from the radiologist to the referring physician, should identify factors that can limit the sensitivity and specificity of the examination, including patient anatomy such as dense breast pattern. A referring physician who is alerted to a patient's breast density should only use the information together with other pertinent patient medical information, such as the patient's cancer history, family history of breast cancer, past surgical history, to decide if additional breast cancer risk assessment and/or supplemental screening are necessary.
Although dense breast pattern has been shown to lower the sensitivity of mammography, which is lower now with digital mammography, there is insufficient consensus in literature to indicate that, on its own, it warrants supplemental screening or diagnostic procedures, such as ultrasound or magnetic resonance imaging. We strongly question, however, how patients may interpret the specifics of the information about breast density and whether it will be of benefit or lead to confusion or other unintended consequences for the patient, which I will describe.
In addition, if it leads to unnecessary testing, non-scientific approaches to screening, or a significant increase in the number of benign breast biopsies, it has not been a positive contribution to patient care. We would support the Canadian Breast Cancer Screening Initiative (CBCSI) position that it is premature to require screening programs to systematically inform women of their breast density.
A number of jurisdictions already indicate in the screening report that mammography does not detect all cancers. Patients are already becoming aware of this fact.
In conclusion, radiologists are encouraged to continue to use standard classification of breast tissue density on mammography reports, in accordance with the ACR BI-RADS lexicon, and CAR guidelines.
Given that there is currently no evidence that additional screening with breast ultrasound or MRI reduces breast cancer mortality in women with dense breast tissue, and a lack of consensus on what risk this represents to the patient, the false positive diagnoses and the high number of biopsies, we seek to avoid increasing confusion and anxiety amongst women regarding the fear of breast cancer.
We would be happy to answer any questions you may have. Dr. Seely is an MRI expert, among other things.
The Chair: Thank you very much.
[English]
Honourable senators, could I get your agreement that if Dr. Duchesne arrives we would let the answer to a question already posed finish and then immediately invite her to present? Are you agreeable to that procedure?
Hon. Senators: Agreed.
The Chair: I will now open the questioning, beginning with Senator Eaton, to be followed by Senator Seidman, to be followed by Senator Eggleton.
Senator Eaton: May I quote you, Dr. Lévesque? "CBCSI's position [is] that it is premature to require screening programs to systematically inform women of their breast density." Could you elaborate on that sentence?
[Translation]
Dr. Lévesque: If you systematically indicate on the copy of the mammography report sent to the patient that she has dense breast tissue, what will she do? She will go on the Internet and find all sorts of information.
We believe that awareness must primarily come from the attending physician and the referring physician. I may get a screening report that shows dense breast tissue. We are screening experts. Not all cases require additional investigation. Often, we have previous reports that we can use for comparison purposes. If I still see that the mammary parenchyma is really distorted and that it is outside the range of being able to properly do the screening mammography, I will mention in my report to the attending physician that the mammography is restrictive, and that either a clinical examination of both breasts or other complementary examinations should be considered.
Some women will probably be able to properly assess what that means. For most people, we will be increasing the risk of anxiety and put them in a situation where they might twist the doctor's arm to order an ultrasound or MRI. But our current health care system does not have the resources to systematically perform ultrasounds on all women with very dense breasts, which represent 30 per cent of the breast cancer screening volume.
[English]
Senator Eaton: If I could sum up, you are saying that unless you pick up something very extraordinary, you will refer it to the doctor that is looking after her and it is up to the doctor to judge whether he should discuss it with the patient.
Dr. Lévesque: I think it is a good practice right now.
Dr. Jean Seely, Working Group Member: CAR Practice Guidelines Breast Imaging, Canadian Association of Radiologists: If I could speak to the assessment of risk, I think one of the more important risk factors is family history. Family physicians are often very aware of what that family history would be. If they have one, two or more than two first-degree family members with breast cancer, that would be an indication that they are at a higher relationship for additional screening. That risk factor would potentially be much more significant than the ones we were talking about here with breast density.
The Chair: As per our agreement, when Dr. Nathalie Duchesne arrived we said that we would finish the response to a question on the table and then invite her to present. I should note for the audience that Dr. Duchesne is the associate of the Clinique radiologique Audet and is a breast radiologist.
Please make your presentation.
Dr. Nathalie Duchesne, Breast Radiologist, Clinique radiologique Audet: We are here this morning basically for different reasons, but one reason bringing us together is that we all know if we find breast cancer when it is very small that we can improve the survival of the patient. "Small" means that it is smaller than one centimetre. If we find breast cancer when it is smaller than one centimetre, the survival rate is up to 97 and 100 per cent over 15 years. This was published in 1999. We started breast cancer screening in 1990s in Canada in order to decrease the mortality associated with breast cancer.
Now, if you look at Canadian cancer statistics, we see that we have observed a decrease in the mortality associated with breast cancer, but over the past 10 years, it has been slowing down. This decrease is, some say, at 2 per cent per year, but if you look at the numbers it is not really at 2 per cent. Perhaps we should wonder why, since there has been an amazing improvement in the mammography over the past 20 and 10 years.
I am sure that you have had other experts showing you images, the difference between the film mammography and the digital mammography. The differences are amazing and one should wonder why, with these big improvements in the technology, we cannot decrease the mortality more than this. Why are we still dealing with stages that are high in Canada? We are not in Timbuktu. Why do we not find all cancers when they are smaller than one centimetre? Why are Canadian women dying of breast cancer in a country with a screening program?
It is because we have not dealt with something that is a risk factor that no one can control. It is not about smoking; we can stop smoking. Obesity is a risk factor; we can stop eating. However, at first we did not know that breast density was a risk factor and now we know it is and we cannot control it. You have dense breasts or you do not. There has been nothing done so far for the breast density risk factor. That is why the companies and researchers that you will hear have worked very hard on how we can perhaps decrease breast density. We know these days that maybe vitamin D is the answer, but until we know for sure we need to find the cancer in those women with dense breasts.
Two or three modes of imaging have demonstrated that they can help, can be adjunct to mammography. One is MRI, but it is very expensive. It is not at every street corner in Canada. It requires an injection, and although it is very sensitive, it is not very specific. That is why we only do screening with MRI for high-risk breast cancer patients.
However, two other modalities are showing that they can find breast cancer smaller than one centimetre and one is definitely tomosynthesis. The reason it works on thousands of women going towards this tendency, but definitely the breast ultrasound. As I came in, I heard Dr. Lévesque. We all agree, as radiologists for the past 30 years, that we know we find breast cancers with breast ultrasound that we cannot find with mammography simply because breast cancer is dark in an ultrasound and it is over white breast parenchyma. That is why we can detect it easier.
Over the past 30 years we wondered how to use breast ultrasound as a screening tool and could not figure out how because it is operator dependent and reader dependent. Three companies on the market now have developed other breast ultrasounds that seem to be a solution to decrease operator dependency. However, we still have reader dependency. With ultrasound used as a screening, we are now finding three times the cancers. We have tripled the detection of cancers smaller than 1 centimetre, and that has been demonstrated by different groups all over the world, in Europe as well as in the U.S.
Having said that, we have the tools, but a fool with a tool is still a fool. Yes, with Bill C-314 we have the capacity to tell women they have dense breasts and therefore we can do an extra test such as ultrasound, tomosynthesis or maybe an MRI.
However, what we need with this law is the ability. Unfortunately, in Canada the system is not well organized to investigate breasts. If we tell the women they have dense breasts, we will need to tell them where to go. We have a problem with the resources, the expertise. I am not saying we do not have the experts, but the experts are not well organized, let us put it that way.
Expertise in breasts is not encouraged for different political, economic and legal reasons, contrary to other countries where expertise in breasts is really encouraged.
There are also people saying that it is not worth detecting breast cancer in dense breasts because most of the time those dense breasts are found in young women 40 to 49 years old. Should we screen the 40 to 49 year-old women? I have slides here demonstrating that if you look at the costs per lives saved in 40 to 49 year-olds with dense breast, the cost per lives saved is more than 100 times less than the sprinklers in this room. No one ever argued about those sprinklers in the law. No one ever argued about anti-seismic construction. The cost of lives saved is $1 million more than the cost of screening for 40 to 49 year-olds.
There is a problem with lobbying in Canada for women with dense breasts, and there is a problem with reorienting our resources — it is not that we do not have them. We should use this bill as a tool. Certain paragraphs in the bill will help with dissemination of information and will help the provinces to organize further tests. Let us not wait for another bill that will give more federal jurisdiction to the provinces to organize for the health of breasts because it will take years. Meanwhile, women are searching the Internet and learning about breast density and know that there is something going on. Let us use this bill and one of the paragraphs in the bill to help Canada develop the resources for the provinces to deal with organizing the expertise.
Senator Seidman: A recent study in August 2012 shows that breast cancer patients with dense breasts were no more likely to die than were other patients in the study. Although dense breasts may increase the risk of cancer, and that is controversial, women with dense breasts respond better to treatment. Therefore, they are less at risk of dying from breast cancer. Would you respond to that?
Dr. Seely: That is correct. I am aware of that study. There is nothing about having dense breasts that increases your risk of dying from breast cancer, as that study confirmed. Just because you have dense breasts does not mean you will respond to treatment any differently or behave any differently. It is only one factor to measure in the whole gamut of breast cancer screening and diagnosis. Breast density is only one risk factor, and there are many other very important risk factors. One of the points that we wanted to make is that if we focus only on this, we may miss the opportunity to focus on other risk factors that may be even more important, such as family history and prior history of other breast diseases.
We recognize that breast density makes people very concerned. One of our fears about this bill is that it will greatly increase the anxiety of women without knowing really what to do. We offer screening breast ultrasound at the Women's Breast Health Centre of The Ottawa Hospital. However, as Dr. Duchesne mentioned, we have very limited availability of qualified technologists' and radiologists' time to offer this in a massive way. Our concern is that if we let women know about this density, one of the risk factors, we will not have the opportunity to actually deal with it. We want to minimize the anxiety when there is a great deal of anxiety about breast cancer, which is always augmented by the media and by these bills. That is why we are concerned if we mandate it.
[Translation]
Dr. Duchesne: I agree with Dr. Seely. However, I would add that some risk factors can be controlled, while others cannot. For instance, we cannot control the family risk, but we treat those patients differently. The patients who have a family history of breast cancer have a mammogram every year instead of every two years. Those who have very high- risk genes have more thorough screening with regular MRIs and mammograms.
The study you are referring to shows that a person with dense breast tissue, with a cancer of 1.2 centimetres, does not have a higher risk of dying from the cancer than a person with fatty breast tissue with a cancer of 1.2 centimetres. A 1.2-centimetre cancer in dense breasts is not more dangerous than a 1.2-centimetre cancer in breasts that are not dense. The outcome is the same. It all depends on hormone receptors, lymph nodes and a whole host of things. A cancer is a cancer. The density of the parenchyma prevents us from detecting it. Are we going to ignore the risk factors that we cannot control by not telling patients that they have cancer in their family history because they will be worried? The situation is the same. They are at higher risk because of the family history and they are at higher risk if they have higher breast density. We have the tools. We must not fall into the trap of not providing a service because we are not well organized. Let us get organized and let us take advantage of this bill to get organized.
[English]
Senator Eggleton: Let me start with the Canadian Association of Radiologists. In your presentation, you paid a lot of attention to the question of confusion and anxiety. I presume that when a radiologist completes a mammogram, it is sent to the family physician. You said you are concerned that many women will search online to figure out what it all means and what they should do about it, but is not their first point of contact their physician? Would the physician not have a responsibility to allay their fears?
Dr. Lévesque: That is a very good point. One of the main areas for education is the referring physician. That is probably one of the key points of the solution.
Dr. Duchesne mentioned the point of organization, which we will come back to. It is what I do on a regular basis during my workday.
[Translation]
When I use the screening mammography and I see dense breasts, I will very often advise the attending physician in my report that the breasts are in fact dense, which limits the level of screening through mammography. It is up to the attending physician then to do the follow-up. In my view, that is the major, key role of the attending physician. He must then factor that in with other aspects, such as previous examinations and the patient's history.
The real issue is the way health care is organized. Dr. Duchesne talked about tomosynthesis and whole breast ultrasound. We are just starting to implement this technology here. Very clear studies in Europe — and I was at the conference organized by Dr. Duchesne — show that tomosynthesis will significantly increase the ability to detect cancer in dense breasts. We are just starting to implement the technology.
We have been using the breast ultrasound for a number of years. When I examine a patient for a specific problem, as the doctor to my right said, in relation to ultrasound screening, the time ratio is one to three for the technologist and the radiologist. Even if we were to have all the mature technology we need by tomorrow morning, we would need to find a way to streamline everything and treat the right patients. Unfortunately, we do not have the necessary technological infrastructure in Canada.
Whole breast ultrasound devices have not been approved by Health Canada yet and we do not have enough technologists and radiologists to deal with such a large number of patients.
When the screening programs were developed a few years ago, at least 15 years ago in Quebec — it was in 1998 — I was at the helm of the provincial association to implement them and we have since come a long way in terms of the skill of radiologists. With the CAR standards and guidelines, we used to require radiologists to read a minimum of 500 mammograms a year. Now, most radiologists read 1,000 or more. We have made significant technological progress in terms of the availability of ultrasound devices in order to meet the needs of the screening program.
However, we do not currently have the appropriate platform for tomosynthesis or the validated and approved technology to be able to say that, by tomorrow morning, we would be able to do it.
I agree with the fact that we need to find cancers that are smaller than one centimeter, but we do not have the tools to do so overnight.
The work that you are currently doing is outstanding and it is certainly a way to raise awareness and see if there is a way to have a national program at some stage. Clearly, it is up to each province to decide; health care falls under provincial jurisdiction. I can understand that the provinces, before embarking on systematic programs, because it is a second level of systematic breast cancer screening for patients like that, I will not hide the fact that I do not think they have the financial resources to do so.
[English]
Senator Eggleton: I was struck by Dr. Duchesne's phrase that a fool with a new tool is still a fool. I take it you are saying there still needs to be a lot more education and training. Could expand upon that? Why do you think the bill helps or does not help in that regard?
[Translation]
Dr. Duchesne: This actually sort of continues along the same lines as Dr. Lévesque's comments. First, I would like to say something about patients' anxiety. Studies have shown that, when patients undergo additional examinations, three months later, they say that they are not under psychological stress. On the contrary, they are pleased they were examined more. Patients are stronger than you think. Stress may not be all that it is made out to be.
Now, where do we refer patients? As Dr. Lévesque said, we are at a second level of screening. The first level is mammography and, if the mammography shows dense or heterogeneous breasts, further investigation is required.
I would also like to make a small correction. Automated ultrasound has been approved by Health Canada as an aid to mammography for screening, and it is available across Canada through various companies, as is tomosynthesis. There are little concerns with Health Canada, but once again, this is used as an aid and does not replace mammography.
I did say that a fool with a tool is still a fool because people need to understand what they are doing with these tools, and it is the organization, the experts. At that second level, you need to have breast experts, experts in breast imaging, who do this level of screening. We cannot ask every radiologist to know everything about screening techniques.
As Dr. Seely said, ultrasound screening takes time. Whether it is automated or not, you need to be used to doing a breast ultrasound. Therein lies the problem: the experts are not organized, and the experts are spread out throughout the groups of general radiologists. Canada certainly has to take a leadership role in that area.
Take the United Kingdom, for example. Why does the UK program work? First of all, screening is only read by experts. There are no general radiologists, and only radiologists who are very specialized in breasts read them. They must read a minimum of 5,000 results; in Sweden, it is 10,000. Here, the number is around 1,000. They are also required to attend interdisciplinary meetings; here, they are not. There is oversight and, if you do not pass the test somewhere else, you no longer have the right to do the screening. So women are protected. This level does not exist in Canada. Therefore, passing the bill and being disorganized the way we are now will not help. This bill should be used to organize the care.
[English]
The Chair: I would ask the witnesses to be more efficient in their responses. I have certain senators left here. We want to get them in before we end this at 11:30.
Senator Dyck: Dr. Lévesque and Dr. Seely, I was struck by what you said about the risk factors that can put a woman at risk for developing breast cancer. This bill addresses only one of those risk factors. Dr. Duchesne, I believe you also said when a doctor is communicating with a patient they should take all those risk factors into account.
Is there anything in place now, or that should be in place, that would require the doctor to include all the other risk factors? This will say you have to tell a woman about dense breast tissue. If it were a genetic factor or occupational hazards, does the doctor have to communicate that and how will this help then?
Dr. Seely: For all breast imaging exams, a questionnaire filled is out by the patient. In that questionnaire she is asked about her risk factors, such as how many family members have had breast cancer or whether she has had prior biopsies, and most organized screening programs will have access to that. The radiologist always accesses that information. When I interpret a mammogram, which is screening, and I see that she has a strong family history or she has had a previous breast biopsy that showed lobular carcinoma in situ, then I will suggest in my report that she needs additional screening. That would probably be with MRI if she qualifies for that risk factor. If she has dense breasts I may add to that.
I wanted to clarify what Dr. Lévesque said about the whole breast ultrasound. Some companies, and Dr. Duchesne works with one of the companies, have two centres in Canada where they offer this automated whole breast ultrasound. GE, which is a major vendor of automated whole breast ultrasound, has not obtained Health Canada approval for its machines. It is true there are some companies, but there is still quite limited access.
The Chair: For the record, it is important for us to note that SonoCiné, of which I understand you are a shareholder, is an automated whole breast ultrasound system.
Dr. Duchesne: That is why I declared already that I was a shareholder and on the medical board of advisers, and I am also on the board of CAR as a member.
The Chair: It is important with regard to disclosure that that is on the record. Thank you.
Senator Seth: This is a never-ending discussion. It is quite interesting.
Dr. Lévesque, you have said:
In conclusion, radiologists are encouraged to continue to use standard classification of breast tissue density on mammography reports, in accordance with ACR BI-RADS lexicon, and CAR guidelines.
Could you explain what that means and how you grade? It will be very interesting for the audience to know about this.
Dr. Lévesque: In fact, it is an international classification. When you read screening you have this categorization, which will be updated. An update is coming up but, as an example, I will say this is probably a fatty breast, so it is category 1. After that it is a mid-1 and it is from 0 per cent to 25 per cent, 25 per cent to 50 per cent, 50 per cent to 75 per cent, and more than 75 per cent is considered the dense breast that we speak about. It is where the discussion is right now. It is a guide for the physician and it is a way to do standard reports. Most of the breast screening in the world uses that, so physicians know what kind of breast it is.
Family physicians or OB/GYNs, as you are, receive a report that says it is a dense breast. It is already a light which is open for the physicians who are used to receiving these kinds of reports. As a screener, when I read the mammography I see when there is some other abnormality or perhaps more difficulty.
[Translation]
When I read the mammography, I put other elements in my comments, such as the breast parenchyma is typical of fibrocystic dysplasia; there are a number of nodular focal lesions — I do not use the term "mass" — that really should be investigated by ultrasound. And it is the attending physician who decides, the attending physician who has all the information.
Most of the time, the attending physicians do exactly what the radiologists say. Because we are still the imaging experts and we are the ones with the experience.
I would like to come back to the number of ultrasounds. Yes, there is a consensus in the literature on the fact that radiologists who read more than 1,000 exams a year have a better positive value rating and a lower recall rate. That is what we are using in several jurisdictions now. Canada is a very large country, and it is also important to consider that we need to serve remote regions. There is currently a screening program in 10 provinces, and there are a number of provinces that use mobile units specifically for remote regions. Screenings are read by radiologists who are very well trained in this.
Of course, the very specialized centres are there. Dr. Duchesne and Dr. Seely work in very specialized centres, but I would like to point out that we have a relatively good screening program in the various jurisdictions in Canada.
[English]
Senator Enverga: It was noted that you have three machines that work well or do not work well enough and one is the breast ultrasound. If you have a breast ultrasound and you have a good radiologist, will it be enough? Will it be a one-stop shop for breast cancer detection?
Dr. Seely: Patients ask this all the time: "Can I just have an ultrasound and not a mammogram?" That is the whole point. We always start with the mammogram. I know you have heard presentations from Greg Doyle and Christine Wilson and a number of experts with eight randomized control trials showing the importance of screening mammography. It picks up the calcifications, architectural changes on the breast; that is not just density and we cannot pick it up any other way. We always start with a mammogram. If we do additional testing to do an ultrasound, that is another test on top of it. Then we have to do a biopsy to prove there is cancer.
I know you have heard that one of the big problems with screening ultrasound is that the number of false positives is five times higher, so if you have 100 women who have a screening mammogram, only 1 will have a biopsy. If you have 100 women with a biopsy recommended by a mammogram, 40 will be cancer. If you have 100 women who have a screening ultrasound, 5 will be recommended for biopsy, and out of 100 women who have a biopsy recommended on ultrasound, only 6 per cent will be positive. It is a six times higher false positive biopsy rate with ultrasound and a five times higher false positive recall rate for biopsy.
A lot of extra tests must be done. Not only do we have to do biopsies, we have to do follow-ups. If we see something on these tests, we have to do follow-ups. We take all of our time that we have dedicated to investigation and we fill it up with a lot of these false positives and it clogs the system. We have to be very careful about the other tests we add to a population-based screening program and the effect on cost and on the patients themselves and to our whole Canadian system.
Dr. Duchesne: I totally agree with Dr. Seely that ultrasound cannot be used alone. It is really to be used as an adjunct to mammography, especially because of microcalcification and the distortion that we do not see well on ultrasound.
I want to ensure that you understand there are two types of ultrasound. There is the inhale ultrasound and the automated. The automated was developed so that we take less time. I am not saying that automated is the only one. Regular ultrasound that is available in any hospital in any clinic of Canada can be used as an adjunct to mammography by a good radiologist to look for breast cancer.
Senator Enverga: It is about the fool and the tool. Do you mean that a lot of our radiologists need more training or upgrading to use the newest tools?
Dr. Duchesne: Of course, I have a different disclosure. Yes, it was the automated whole breast ultrasound, but I am a woman and a breast radiologist, so I am speaking as a specialist. That is all I do in life; I do breasts. I am not a general radiologist. I believe in Mister Muffler for cars. If I have a problem with my muffler I prefer to go see Mister Muffler than a global mechanic. If I have a tumour in my head, I will go see a neuroradiologist and no one questions that. If we go to this level that there is probably something in the breast, I do not see why you would not go see a breast radiologist.
I am not saying that we do not have breast radiologists in Canada; not at all. We have them, and yes we definitely train them. We have fellowships in breast radiology, et cetera. I am saying that they are diluted and not encouraged to work in an organized centre in the whole of Canada. Dr. Lévesque was talking about this vast country. The solution to that is centralized reading. Women must have access to their mammography all over the place, to their MRI, to their ultrasound, but the reading can be centralized by specialists.
[Translation]
Senator Verner: This is a complex issue, and there are various ways to address it. I must say that I am particularly proud to have you here this morning because I have been a client of the breast disease centre at the Saint-Sacrement hospital for 25 years. So I could not help but recommend that you be invited here this morning.
Having said that, we are talking about the issue, and I have various questions about dense breast tissue. I have no knowledge of medicine, but my understanding is that it is a factor that should motivate or influence the way cancer is detected, but it is not necessarily a factor that has an impact on cancer treatment or the mortality risk. Is that correct?
Dr. Duchesne: That is correct.
Senator Verner: I often hear — and I say this as a woman — things like: it is not a good idea to tell patients that they have dense breast tissue because it creates anxiety. It is a little difficult for me, in 2013, to hear something like that. Not to be mean, but I find it a little maternalistic. In 2013, in the Internet age, I think any woman here around the table — and the men, too — can get information on what is going on elsewhere.
I think I understand that it is perhaps better that a woman is not told that she has dense breast tissue because problems arise at the next stage, not in the woman's ability to comprehend a factor like that.
Dr. Duchesne: I agree with the fact that, in 2013, women are not yet patients, and they have access to the Internet. Canadian women are just as smart as American, European and other women. They see what is happening with the legislation on the obligation to provide breast density. Women are going to ask for it sooner or later. I think we need to use this bill to determine what direction to take, once they have been told.
Dr. Seely: I agree with the fact that we have to treat patients with respect and give them the opportunity to know. At the CAR, we recommend having the density reported on every mammography, which is not done the same way in all provinces. In Ontario, it is more or less 75 per cent, but in other parts of Canada, it is done with the four existing categories.
Every patient has a right to a report. It is a universal principle in medicine. This legislation does not exist in other countries, save for in six American states. What will happen if this information is given to all women? They will think they have to undergo more testing.
It is not that we do not want them to have the information, but what are they going to do if the legislation stipulates that everyone must have a report?
Dr. Lévesque: My spouse is a pathologist. I have one daughter who is a radiologist and another who is a dentist. Let us be honest: women have a level of understanding that is higher than men's, not to point that out.
I have been a member of the board of directors of the American College of Radiology for the past two years, and they have asked me to sit as an observer. I have seen what has happened with the legislation there. The problem is the way women interpret the information they receive. Let us be honest, there is a forensic issue as well. I have been a radiologist for 33 years. I can spend half an hour doing an ultrasound on a woman, and I can miss something. We know that 4 per cent of our radiology reports are not what they should be.
Having said that, I believe that there really is a problem with the organization of care. We are at the stage with this situation that we were at 15 years ago when we started screening. I find that it is very important that, as representatives of a national government, if you are going to use this bill effectively to promote and do phase II screening, I am totally open to it as a radiologist. I do this screening on a daily basis.
However, I have difficulty seeing myself in the current situation where attending physicians would be inundated with calls. I can tell you what is happening in Massachusetts and other states. In the United States, you can ask for an ultrasound or not. Ultrasound training for American radiologists is different than the training in Canada. For the most part, Canadian radiologists are able to verify the work of technologists. That is a second level that does not currently exist in the United States.
Yes, it is very good to be able to direct it in the context of a second screening, but honestly, we do not have the resources we need to do 15 additional screening ultrasounds. We will quite simply not be able to do it. I think the right information needs to be given. There must also be coordination with the various jurisdictions through the federation or another organization.
Senator Verner: I would have one last question about the bill.
[English]
The Chair: I thank the witnesses on behalf of the committee.
We are very pleased to welcome two more witnesses to our discussion. Dr. Boyd, please proceed.
Dr. Norman Boyd, Senior Scientist, Campbell Family Institute for Breast Cancer Research, as an individual: I circulated in advance a summary sheet. I apologize if it covers material already familiar to you. It will not take me long to go through it and establish some basic facts that appear to be in dispute from the earlier discussions that I heard.
Density is illustrated in the figure at the top right-hand corner of the sheet. You can see there are mammograms with varying amounts of white in them. The white is referred to as breast density. You can see that it may occupy the entire breast, as in panel F, or it may be completely absent, as in panel A, or it may be present in intermediate amounts in the remaining mammograms.
These variations in the appearance of the mammogram reflect variations in the underlying tissue composition of the breast: The breast lobules that make milk under appropriate circumstances; the ducts that conduct the milk to the nipple; and the connective tissue that supports those tissues looks white, while fat tissue looks black. Variations in these tissues cause the variation in the appearance of the breast.
Why does density matter? I think there are three reasons. The first is the one you spent most of the last hour discussing: It makes breast cancer more difficult to detect. The difficulty increases with increasing amounts of density in the breast; therefore, breast cancer is most difficult to detect in panel F and easiest to detect in panel A.
The second is that breast density is associated with an increased risk of breast cancer. When someone says that something increases the risk of breast cancer, the next question, I would suggest, is: Compared to whom? If we compare someone with the appearance in panel F to the appearance in panel A, we see that the gradient in risk is something like four-fold or five-fold, which is much stronger than any other risk factor except for age and the few genes known to create a very large increase in risk.
The difference across the spectrum of density is very strong. One can also compare people with above average density, let us say those in panels E and F, with women of the same age, for the same length of time in the population and find the increase is about two-fold. The "Compared to whom?" question has a profound influence on the quantity that one assigns to risk.
The third reason for being interested in this subject is that density, in contrast to almost all other major risk factors for disease, can be changed. We know little about how to change it at the moment, but we know that some women who take combined hormone therapy — estrogen and progesterone components — may experience an increase in density. Women who take tamoxifen, a drug used to prevent breast cancer, may experience a reduction in density. It can be changed by some things. There are also more general influences, such as having children, aging, menopause, and so on, that also decrease density. It is not an immutable thing. Whether these changes are associated with changes in risk is much less certain. Some exposures, like tamoxifen and hormone therapy, appear to be associated with both changes in density and changes in the risk.
In terms of what can be done to decrease the risk if a woman is told that she has increased density, if she is on hormone therapy and her density has increased, she might discuss with her doctor whether it is advisable to stop. Similarly, if she is very concerned about risk, and perhaps there are other risk factors in addition to density, it might be appropriate to consider taking tamoxifen as a preventive treatment.
One of the puzzles about density is it that it becomes less as women get older, whereas we know the incidence of breast cancer increases. Data not yet published shows that if we consider cumulative exposure to density, not just the level of density but its duration, and integrate the area under the curve created by plotting those things, we find a function that increases with time and is very closely related to the age-specific incidence of breast cancer in the Canadian population.
Current research on density is focused in a variety of areas. One is the development of methods to predict breast cancer risk using density and all the other risk factors that we know about and automated methods in the form of the Gail model. They are all available on line for anybody to access and use. There is research on development of methods to measure density, particularly automated methods, and Dr. Yaffe is involved in that enterprise.
We know that density is a highly heritable characteristic. One of our New England papers that I included was a twin study with about 1,000 pairs of twins collected in North America and Australia. In both populations, it shows very strong evidence that inherited genes influence the type of density that women develop. Research to try to identify those genes is in progress.
We are also engaged in research on the origins of density in adolescence. We are looking for factors in growth and development both before birth and after birth. We find convincing evidence that they affect the way in which breast tissue develops in adolescence. Development in adolescence determines essentially what will happen throughout the rest of the woman's life.
The Chair: I now invite Martin Yaffe to present.
Martin Yaffe, Senior Scientist, Sunnybrook Research Institute, as an individual: Good morning, and thank you for inviting me to testify at this Senate committee considering Bill C-314 on the issue of communicating information regarding breast density. You have heard much about breast density before, so I will tell you about my background. My value here may be mainly in answering questions you may have.
My background is in medical imaging physics. My research has been devoted to the development of new techniques that can more accurately detect breast cancer. My group at the University of Toronto helped to lead the development of digital mammography, which is now the major technique used for breast cancer screening. The first funding for this research came from the former medical research council of Canada now known as the Canadian Institutes for Health Research.
We designed digital mammography precisely to attempt to overcome the problem of finding breast cancer in the dense breast. In a study carried out in the U.S. and Canada in which over 50,000 women participated and were imaged with both technologies, we were able to publish our findings in the New England Journal of Medicine that showed that digital mammography was substantially more accurate than film in those women who had dense breasts.
I was co-author of a study led by Dr. Anna Chiarelli from Cancer Care Ontario and published a couple of weeks ago. It showed that one type of digital technology was less effective than other types in detecting breast cancer. I have collaborated with Dr. Boyd for many years on measurement techniques for breast density. The technique that we developed together is used in many epidemiological studies by other researchers internationally.
My current work is focused on optimization and evaluation of digital breast tomosynthesis, which is a type of three- dimensional mammography that may resolve some of the problems, but not all, around density and both improve sensitivity of breast cancer detection and reduce the number of false positives associated with breast cancer detection.
I should disclose that I am a founder and shareholder in a company called Matakina Technology, a company that develops software to measure breast density. In light of this, you may be surprised by my comments regarding the bill.
You have heard from Ms. Kimberly Emslie, Dr. Morag Park and others about the fact that breast cancer is a major killer of women. You have also heard that high breast density imposes two different types of risk. First, women with dense breasts are more likely to develop breast cancer than women of the same age with less dense breasts. Second, mammography and even digital mammography is less accurate in detecting breast cancer in the dense breast and in determining that breast cancer is not present where it is present. The false positive rate is higher in the dense breast.
Bill C-314 is well intentioned in expressing the value of communicating to both a woman and her health care provider that she has dense breasts. Certainly this information, as you have heard from Dr. Boyd and others, is potentially valuable. With reference to the first type of risk, it is important to know that there are many other risk factors for breast cancer besides density. Related to this type of risk, we are only getting part of the story in the discussion of density, so the discussion needs to be more complete. I see density as one tool that would inform a more extensive discussion between a woman and her primary health care provider regarding the issue of risk.
The second type of risk, missing cancers in dense mammograms, could be more directly addressed by providing a woman and her health care provider with information regarding her breast density. I strongly believe that both should be informed if it is deemed that there is a reasonable probability that a breast cancer will be missed because of obscuring density. This could trigger a recommendation for the use of additional or alternative screening modalities that would be less negatively affected by the presence of density. Some of these have been evaluated for specific indications but not generally necessarily for general screening or for dense breasts. Therefore, further research is necessary. In spite of that, there is reason to believe that these techniques will provide more useful images in women with dense breasts. Examples are ultrasound, digital breast tomosynthesis and breast MRI.
The goal could be achieved more reasonably with the adoption of appropriate clinical practice guidelines requiring clear communication of concerns regarding density, rather than through legislation. Until we have further evidence on the efficacy of these new imaging tools, like MRI and ultrasound for general screening purposes, I suggest that the person best qualified to determine whether the presence of density is likely to interfere with accurate interpretation of a mammogram is the radiologist. This is the person who could most competently advise on whether ultrasound or MRI should be used in a specific situation in addition to or in this place of mammography for an individual woman.
There are, however, important areas in which the Government of Canada could beneficially influence the practices of breast cancer detection through screening. For example, the policies across the provinces on standards for screening are not consistent, particularly with respect to the age at which women are allowed access to organized provincial or territorial screening programs. The Canadian government could, through the CBCSI, influence a move to harmonize these policies across the country.
The recent recommendations of the Canadian task force, which based its analysis on data that were not reflective of the performance of modern breast screening technologies, did not provide a clear picture of the benefits of screening, nor on the severity of the toll of breast cancer on younger women.
For example, 14 per cent of the deaths due to breast cancer and 18 per cent of the years of life lost to the disease come from breast cancers diagnosed when women are in their forties, a period during which the task force has recommended against routine screening.
My research suggests that approximately 200 lives could be saved in Canada each year if women in their forties participated in breast cancer screening, but the task force recommendations have actually discouraged these women. As you have heard from Dr. Wilson a couple of days ago, not only women in their forties but many over the age of 50 have been discouraged from participating in screening because of the message from the task force. Screening is like fire insurance. Most people do not benefit from it but those who do benefit do in a major way; not just through aversion of a premature death, which is very important, but also through earlier detection and allowing a woman to avoid possibly some of the harsher aspects associated with treatment of advanced disease.
Here are four other opportunities that could help us to achieve maximum impact against breast cancer and are amenable to action by the Government of Canada.
There are still important unanswered questions surrounding some of the issues of which I speak. The government can ensure that federal funding agencies have the resources to provide adequate research funding toward the causes of breast cancer, its possible prevention and improved methods for detecting those cancers that have the potential to be lethal since not all breast cancers will necessarily become lethal.
It also would be of value to implement standards to ensure that all of those who interpret screening mammograms have appropriate experience and training, and therefore see enough breast cancers per year to be truly competent at this. You have heard some remarks about that before.
Additionally, it would be of value that the government exerts its influence such that screening is moved towards being done through organized programs rather than opportunistically. Organized programs offer routine invitations to women at the proper intervals for screening, quality monitoring standards and measurement of outcomes associated with screening.
The Chair: I remind senators that by agreement of the committee this session will end no later than 12:30. Since I had to cut off Senator Verner in the last session, I have placed her third on the list and I will begin in the regular way with Senator Seidman, followed by Senator Eggleton, to be followed by Senator Verner.
Senator Seidman: Both of you have made it very clear that density is a fairly complex issue and, as a single risk factor, likely not the best way to inform women about their risk status. One would have to look at a whole variety of risk factors in combination with density. We have heard this from you and we have heard this from other witnesses.
I would like to ask you very specifically about actually assessing density. We have heard from other witnesses that to have any objective measurement of density is difficult. There seems to be not only a reader bias or lack of reliability but there is also no absolute measure, or agreement on an absolute measure, on how to measure density. Could you comment on this please?
Mr. Yaffe: I mentioned the two types of risk for the risk associated with higher risk of having cancer. An objective measurement and a precise one is of great importance and perhaps Dr. Boyd will speak more about that.
For the second one, to determine whether a mammogram because of density may not be as useful as it might otherwise be, a much simpler criterion can be used. You saw the images Dr. Boyd showed you and it is easy to see the difference between a very dense breast and a less dense breast. Frankly, I would trust the radiologist to be able to make the simple decision that one image is of concern because of density and for another image a mammogram is enough for now. This could be implemented with some training and very simple standards.
Dr. Boyd: The estimates of risk shown in our 2007 New England paper were generated by radiologists. They estimated the proportion of the breast that was occupied by density using a kind of scale that is illustrated in my figure. In Toronto, two radiologists, Dr. Roberta Jong and Dr. Eve Fishell, sat down with each other and agreed on what they were going to call density. We did a study of the calibration and ensured they could be substituted for each other. Then they read the 2,000 or so images that were assembled for the purpose of risk estimation and reproduced risk estimation between the Canadian National Breast Screening Study, the population-based screening program in British Columbia, and The Ontario Breast Screening Program.
Radiologists can do this with their eyes. There is no need for complex measurements. We did complex measurements in association with what the radiologists did and we reproduced what they could already do. It is not as difficult as one imagines. It may be that short education sessions would improve reliability of measurement, but it does not need four years of residency in radiology.
Senator Eggleton: Mr. Yaffe, in terms of your statement about women in their forties, you point out that the task force recommended against routine screening, but you are saying 14 per cent of the deaths due to breast cancer and 18 per cent of years of life lost come from women diagnosed in their forties. You then even say that approximately 200 lives could be saved in Canada each year if women in their forties participated in breast cancer screening. What argument did the task force make for not doing it, because yours sound very compelling, and what do you say about the task force?
Mr. Yaffe: I believe you actually heard from others on previous days when similar comments were made. I think the task force underestimated the toll associated with breast cancer in women in their forties, and I do not know why they did that. They certainly did not look at the years of life lost.
Of course, if a woman dies at age 53 because of a breast cancer that was originally found in her forties, there is a much greater loss of years for that individual and that is a cumulative toll in society, than when someone who dies at age 85 or 90 from a breast cancer. That was not considered, but even in terms of death it is still quite a significant component of the loss of life in the country. They ignored that.
They also did not look at more modern studies, using more modern mammography in conjunction with modern treatment of breast cancer, including some of the new therapies that we have available to us. For example, in British Columbia, a study of their screening program showed a 24 per cent reduction in mortality, which applied to both the younger women in their forties and to older women. Studies that have been done in other countries have even suggested larger benefits extending up into 40 per cent mortality reduction. I believe they underestimated the benefit.
They also put a huge weight on what they call a false positive, and that is not a mistake by the radiologist. A false positive indicates that there is enough suspicion after the initial screening to suggest that a second level of test be done to ensure that cancer is not present. This has been painted as being a huge harm, and if it is not communicated well to women there is stress associated with being recalled after a screening. I think a better communication job could be done to reduce that stress. They put a huge weight on the negativity associated with the so-called false positive, and I believe this tended to colour their thinking on the matter.
Senator Eggleton: Let me ask both of you about the technology. The Ontario government recently put $25 million on the table to replace mammography screening equipment that uses the more traditional form of mammography. I take it that it is to go to digital mammography. Is that the right move? There so many changes in technology. Of course, the Americans are now getting into the ultrasound in terms of dense breasts, over and above the traditional mammography.
Is that the right move?
Mr. Yaffe: This is a fairly complicated question. First of all, their move was not to replace film with digital but to identify one type of digital mammography referred to as CR. In their evaluation — and I was an author on the paper — it did not perform as well as the other type of digital mammography or film, to basically remove that type of technology from the program.
The subtlety is that there are multiple manufacturers of that CR technology. The study was not powered statistically in order to sort out the performance among the different manufacturers, so the government decided to simply replace that generic type of technology with the DR type of digital mammography. There are other factors in the measurements I do as a physicist that suggest that move technically makes sense. The performance should improve, I think.
[Translation]
Senator Verner: Mr. Yaffe, you mentioned that there was an organizational problem with respect to resources. This is something that we have heard from other witnesses as well, in other words, not necessarily telling a woman that she has dense breast tissue, but knowing what happens afterwards. That is where the problem lies, and it is particularly complex when it comes to the organization. Could you please expand on that a little?
[English]
Mr. Yaffe: I am not sure that I said exactly that, but certainly I think, and you have heard from others, that how to communicate the issue is critical. You do not want to create panic. At the same time, if a woman has been examined using a mammography — let us say a site is still using film technology which we know does not perform as well on dense breasts as some of the newer digital systems do — and the radiologist finds the breast is dense and has concerns about the fact a cancer might be present and not seen because of density, I think it is appropriate for a woman and her health care provider to know that so that another examination can be done. It may be just going to a digital system or adding MRI or ultrasound; it is not for me to judge. However, I think the woman should be given that information so she is part of the decision and I do not think it is grounds for panicking. It is simply saying there is better technology we can use in this particular case to get a clearer picture. I think it is the radiologist who can help influence that decision as to who needs the additional views.
[Translation]
Senator Verner: Is there enough training to detect and treat an issue like dense breast tissue?
[English]
Mr. Yaffe: Again, I may have a little built of difficulty with the question, but I think that if it is a matter of recognizing high breast density, as Dr. Boyd mentioned, relatively simple illustrations of the dense breast and non- dense breast, most radiologists who look at mammograms know which ones are problematic. Their job is finding cancer in mammograms. It is a bit like if you are flying in an airplane in the clear blue sky and you see an Air Canada plane painted white. You can see it. If you are flying in a cloudy sky, it is more difficult to see. Radiologists quickly know which ones are more problematic, can segregate them and identify the ones where other imaging is perhaps needed.
[Translation]
Senator Verner: How would you describe our practices in Canada in this respect compared to what is done elsewhere n other countries, for example?
[English]
Mr. Yaffe: Practices in what sense?
[Translation]
Senator Verner: In the sense that there are figures that were mentioned earlier about the target number of radiographs that radiologists do, meaning about 500 to 1,000 mammograms, compared to Sweden, where the number is much higher, and the United Kingdom, as well.
[English]
Mr. Yaffe: I understand. I think the situation has improved in Canada, somewhat. Previously, radiologists were required to read only 480 mammograms a year. At a typical rate of five cancers per 1,000, that means someone might see only two or three screening cancers per year. In my opinion — and I would defer to the radiologists here in the room — that may be challenging to keep up one's skills seeing so few screening cancers.
In England it is 5,000 or 10,000, and that provides a better situation. In the United States it is still 480 and part of it is the availability of radiologists, particularly in smaller communities. If you demand this high volume, you may find some communities do not have somebody to interpret the images. Unless you do more centralized interpretation, which is what Dr. Duchesne suggested, you might be in a situation where you do not have the services available in the community. It is a balance. I do agree that the evidence seems to be that higher volume improves performance both in finding cancers and identifying the non-cancers and not having to call as many women back.
[Translation]
Senator Verner: Since we are talking about resources that are perhaps not as well-organized, that there should be additional training and that everyone is working in good faith on this issue, would you say that with Bill C-314 we are looking at the problem backwards and should instead look at the resources overall that could be improved before getting to that point? Perhaps the federal government's regular agencies like Health Canada or other initiatives could provide information on dense breast tissue, rather than have this legislation address only this subject.
[English]
Mr. Yaffe: I agree and thank you for asking that question. I am glad you asked it. That is why I mentioned that I am not sure a bill is really the best way of addressing this issue. In some places they already report density. If we knew that clinical practice guidelines would be put in place to ensure this was done — and that it is done in a relatively consistent manner — that would address most of the problem. I did mention three or four other issues that I think are more pressing and would have greater impact in terms of saving lives associated with breast cancer detection.
Dr. Boyd: The debate about density raises a larger question. There is great heterogeneity in the population with respect to both underlying breast cancer risk, which is influenced by density and other risk factors, and the ease with which cancer can be detected by mammography. To have screening programs in which there is one modality and one screening frequency for everyone, regardless of this heterogeneity, makes no sense to me at all. There is a need to look at the things in a bigger picture and say there are some women in whom the risk is lower and detection is really easy. Do we need to see those people with the same frequency that we do those in whom risk is high and detection difficult?
The Chair: Thank you both for those important answers.
Mr. Yaffe: I agree with Dr. Boyd on that issue. Not with respect to density as a factor but with respect to other risk factors, in Ontario, a high risk screening program has been implemented by Cancer Care Ontario. Women who have greater than 25 per cent lifetime risk of breast cancer are given the opportunity of being screened with MRI, mammography and/or ultrasound.
The Chair: Thank you very much.
Senator Seth: As I said, this has been an interesting topic.
Dr. Boyd, as you mentioned, breast density can be decreased by stopping hormone replacement therapy or starting tamoxifen treatment. Can you explain what these treatments are typically used for and their side effects?
Dr. Boyd: Hormone therapy is usually given to control symptoms occurring in women at menopause. There is now convincing evidence from randomized trials done in the United States that combined hormone therapy, which is what is most commonly used, is associated with a modest increased risk of breast cancer, which has greatly decreased the use of that drug.
However, in some women, it increases density, and there is evidence, not yet published — the paper on which Dr. Yaffe and I are both co-authors from a study done in the States — showing that the increase in density that sometimes occurs with combined hormone therapy is very closely linked to the increased risk of breast cancer. In women whose density changes on hormone therapy, it should be regarded as a red flag and the question should be raised as to whether they should continue. That is obviously a clinical decision. It depends upon how long the doctor is planning to continue the hormone therapy and how severe the symptoms are that are being treated, so I think it has to be individualized.
Conversely, with tamoxifen, apart from its use in treating breast cancer, its only real use at the moment is in breast cancer prevention, and it is typically given in circumstances where the risk is very high, often with a family history. However, it has recently been shown that in some women tamoxifen decreases density substantially, and the decrease in density seems to be very closely linked to the decrease in breast cancer risk that accompanies use of the drug. This is still, I think, in a sort of intermediate stage; it is not yet ready for clinical practice but it may well become so in the near future.
The U.K. is beginning a randomized trial of women with extensive density who are either put on tamoxifen or not, so we will shortly know what the benefits are. Tamoxifen is not risk free. It can increase risk of clots, pulmonary emboli, strokes and so on. The frequency of these things is very low, but there has to be a substantial benefit in order for these risks to be worth running at all. It is still a little muddy, but it illustrates the principle that density can be changed, and changing it seems to be beneficial in terms of the effect that has on breast cancer risk.
Senator Martin: I have learned from being a part of this committee and serving in the Senate that nothing is simple. This bill is concise, but it is a complex issue. Thank you for the work you are doing on shedding light on this very complex issue.
Dr. Yaffe, in your presentation you mentioned the importance of raising awareness and informing women as well was doctors. You wonder whether it could not be achieved simply through adoption of appropriate clinical practice guidelines.
I think we have learned so much in our committees, and we understand where the gaps are and how difficult it is to close those gaps. You mentioned harmonizing policies with provinces and territories. Could you comment more on the complexity of adopting these clinical practices and/or harmonizing? In the previous session, a witness said this bill — whether it is this bill, an amended bill or another bill — would be the opportunity to begin the process of doing some of those important things to close those gaps. Would you comment on the complexity of trying to harmonize? What challenges are we facing right now?
Mr. Yaffe: With respect to implementation of clinical practice guidelines, I am not a physician myself. It is not clear to me in some cases how simple or difficult this would be to do. I know that in Ontario around the issue of MRI for women at high risk of breast cancer, clinical practice guidelines were established quickly and efficiently over a period of several months using data available in the literature.
I think if there is a will, there is a way to do this, and it should not be that complicated. Many screening programs and many radiologists already report density using the so-called BI-RADS lexicon which is in four categories, and I think the category of greatest concern is the extremely dense one. That is the one where the radiologist will have most difficulty in finding cancers, so I think that it would not take a huge effort, if this was the goal, to achieve some consistency across the country, and using simple tools, illustrations, for example, to try to clarify those definitions.
If you are trying to measure density for the purposes of a trial to see if a drug is influencing density or not, then the tools you need are much more precise. Dr. Boyd and I spent a lot of time working on those things. I do not think that is really what we are talking about here.
We will have such precise tools and they will probably be available in the near future. I mentioned the company I am involved with, and that is what we are doing. There are other people looking at that as well. That may make things easier for the physicians so they do not have to make the decision themselves, but I do think they can make that decision. I agree with Dr. Boyd there.
I am not sure if you wanted to go beyond density, but I think there are, as I mentioned, many opportunities to improve the situation around breast cancer detection in the country. I think these are ones where better consistency among the provinces is required and perhaps another look at the task force and what it has done and to look at whether those are considered acceptable recommendations and, if not, perhaps to consider revising them. The federal government has been rather silent on the issue of its recommendations.
Senator Martin: It is encouraging to hear you say that, and I will specifically connect the work that you do, which is the research. I share the concerns of my colleagues and what we have heard about the capacity in our current infrastructure. If we are to inform, then how would we address the next step of following up on caring for the women with dense breast tissue?
Based on the scientific research, the technologies and the expertise in Canada, do we have the ability to build that capacity if the will is there to bring the stakeholders together to do such good work?
Mr. Yaffe: I believe we do. The difference between the situation we have here and in the United States, where much of the density publicity came from in the legislation, is the way health care is paid for in this country. In the United States, if something is not basically recommended officially, a woman will have to pay for it out of her own pocket. In many cases, that money just does not exist, so important things do not get done.
Here, I believe that in most cases if a physician feels an additional test is valuable, he or she will refer a woman for that test, and it will be done. If my doctor says that I need to go for this additional test, I will take that advice generally.
With respect to having that discussion among professionals in the country, there is certainly more than enough capability among our colleagues to resolve those issues.
Dr. Boyd: The discussion you heard earlier this morning illustrated very nicely that at the moment there is not a strong evidence base on which to make decisions about what further imaging modalities might be used. If the evidence is not available, perhaps we should get it. We definitely have the resources within Canada to compare imaging modalities in a systematic, quantitative way that would provide us with the evidence needed to make these difficult decisions.
Senator Cordy: This has been very interesting.
We are dealing with the subject matter of the bill, which deals specifically with the risk factor of breast density. Mr. Yaffe, one of your recommendations, which you called an opportunity, which I like better, was that federal funding agencies have resources to further research the causes of breast cancer. What information gaps do we currently have related to risk factors for breast cancer that would require substantial research?
Mr. Yaffe: As Dr. Boyd just pointed out, the question is if a woman has dense breast tissue, what would be the best thing to do next? We can make an intelligent guess right now, but the actual evidence in the strictest sense has not been put together. I agree with Dr. Boyd that it could be done in the Canadian environment and it would not be that difficult to do if we just decided to ask the question.
One important thing is that automated breast ultrasound screening is not generally available, but some of the other tools are. Some of these things could be evaluated in what we call the post-market environment; in other words, it is already out there and we could be doing studies to amass the evidence to answer some of these questions, and we could do that without enormous expense.
Senator Cordy: So really this bill is jumping ahead. We do not really know what we should be doing because we do not have the research information to know the next steps for a person who has dense breast tissue.
Mr. Yaffe: Yes. For example, a study on ultrasound screening for women whose only indication is a dense breast has not been done. It has been done for high risk women. The same is true for MRI. Those studies, in the proper context of how you would want to use the information, should be carried out.
Senator Cordy: The research end of that is certainly within the realm of federal government jurisdiction.
You also spoke about implementing standards to ensure that those who interpret screening mammograms have adequate training. Are there currently no national standards?
Mr. Yaffe: The Canadian Association of Radiologists has now imposed the standard. They have raised the standard from the American one of 480 examinations per year to 1,000, I believe it is. They are generally the organization that sets that standard.
Senator Cordy: It would not be the government setting the standard; it would be the organization itself?
Mr. Yaffe: Some provincial programs may have their own standard. My guess is that it is consistent with the CAR.
Senator Enverga: We have two great scientists here. Have you ever done research on the breast density of males? We have been talking about females. I know a couple of males who died from breast cancer and I am wondering if there is anything ongoing in that regard.
Dr. Boyd: I have been asked that question before and I usually reply that women are giving me enough trouble at the moment. I will only deal with males after it is all solved.
The question is quite reasonable. Breast cancer in males usually arises in the setting of gynecomastia, in other words, in the setting of some breast development that occurred in the individual. It is quite plausible that there is imaging information in the male that may be pertinent to risk, but it has never been explored.
Mr. Yaffe: Breast cancer is about 1 per cent as common in men as in women, but little has been done with respect to considering the density issue.
Senator Enverga: You mentioned that there is a lot of research in progress. How far are we from making progress on this?
Dr. Boyd: Next week I am presenting the first results from our study of young women. We are recruiting 15- to 18- year-olds from the Toronto school system. We have ethics approval and cooperation with the Toronto District School Board, the Catholic School Board and some regional school boards outside the city limits. We currently have 700 young women enrolled. They are being examined with magnetic resonance because we do not want to expose them to radiation. Magnetic resonance can be used to characterize breast tissue in the same way that mammography can.
We are accompanying those breast measurements with detailed histories from their mothers about what happened during pregnancy and in the child's early life, as well as genetic and hormonal measurements that we are making in the children themselves.
This is the first study of its kind on this scale anywhere in the world. Next week we will be reporting on the effects of some very early influences, like whether the mother gained weight during pregnancy, what the birth weight of the child was and whether she was breast fed as an infant. These all have an effect on the breast tissue characteristics that we measure when they are 15.
These are very early influences, and they raise the question of something that has been called developmental plasticity. In other words, variations in the environment at critical stages of development can cause the development of particular tissues to proceed along certain lines permanently. This is already established in heart disease, and it looks very much as though it will apply in the breast disease and breast cancer setting as well.
Senator Enverga: I am looking forward to receiving that kind of information.
Senator Eggleton: Bill C-314 is technically not here; it is technically in the Senate. We referred the subject matter of this bill to the committee. This will be our last hearing on this issue, following which we will have to determine what we are going to recommend on Bill C-314.
We have varying reviews of this from a number of people. Some say it might be helpful in some respects, some say it might be harmful, and some say that it does not go far enough. One person I asked the question of said that most of this is being done but the bill adds some emphasis and maybe a higher federal role.
There is minimal information in this bill, which is not a government bill but a private member's bill. Is it helpful or harmful? Does it add sufficient emphasis to make it worth proceeding with or is it not worth proceeding with?
Dr. Boyd: It seems to me that if a woman wants to know what information is in her mammogram that may affect the detection of breast cancer or her future risk of breast cancer, there is absolutely no case for denying her that information. Whether everyone should be told, whether they want to know or not, is another matter. There are other settings, genetic testing, for example, where people can say that they do not wish to know the results. I would at least want to consider that possibility in the context of interpreting mammograms and reporting what they say.
If a woman wants to know whether she has breast density or not, I think she has a perfect right to know. This information is somewhat different from most other medical information about risk. If your doctor wants to know whether your cholesterol or blood pressure are posing any hazard to your health, he actually has to do something; he has to take a blood sample and get it measured or perform a blood pressure measurement. Here the radiologist cannot help but see the risk factor. It is impossible not to see it. The question is, should it be a secret known only to him or her, or should it be transmitted to the subject it concerns, if they wish to have it? I think the answer to that is really straightforward.
Mr. Yaffe: I agree completely. The real issue is whether this needs to be done through legislation. If I was absolutely assured that the CAR would make this part of their standards and that the CBCSI would similarly impose this as part of a screening program — and I heard Greg Doyle speak a couple of days ago here and he was certainly not in favour of this — then I would not see the need for the bill.
I do not know what the options are.
The Chair: I wish to formally thank you, on behalf of the committee, for being here, for the thoroughness of your responses and for the great expertise that you represent.
(The committee continued in camera.)