Health Committee on Dec. 6th, 2023

[Dr. Anna Wilkinson]

It's really simple. A mammogram is where we start. With screening, a mammogram is an X-ray of the breast.

What I and many other experts believe is that screening should start at age 40. Women in their forties should probably have annual mammograms, and then that should continue every two years. If a woman is really healthy and has a good life expectancy in her seventies, then that should continue, probably, to 80.

The biopsies...those kinds of things only come into play if there are abnormalities or suspicions of cancer noted on the mammogram.

[Karen Vecchio, Conservative, Elgin—Middlesex—London, ON]

Wonderful. I have two more minutes.

Continuing on with that, when we talk about genetics, because genetics are obviously a big part of this.... I think I've heard that from each of the panellists today.

Dr. Narod, I want to start with you. When we're talking about genetics and screening, when we're looking at that, when should we start doing the proper screening if we know that breast cancer is in a family's history?

[Dr. Steven Narod]

There are three levels of genetics. One, as Dr. Simard pointed out, is polygenic risk scores, which give you a risk based on 313 variants. That is his study. There are also major genes BRAC1, BRAC2 and PALB2. Jacques and I were actually working on that together back in the 1980s. Finally, there's family history.

[Karen Vecchio, Conservative, Elgin—Middlesex—London, ON]

Should we be doing that at a certain age? When a woman is 20, 30 or 40...? Is there a certain age at which we should start doing a special screening for women with a history?

[Dr. Steven Narod]

It's not so much that we should do the screening as we should do the testing.

One of the most important things, I believe, is that the current policy in Ontario and in most provinces is that we do genetic testing once a woman has developed breast or ovarian cancer. By that time, I think it's a little late.

I set up a program at the Women's College Hospital—the only one in the world—where we make genetic testing available to every woman in Canada from the age of 18 on a pay-per-service basis. We've done several thousand. The premise is that, if we find them before they have cancer, then we can offer them special screening.

In the high-risk women, we do offer MRIs. It's covered by the Ontario government, OBSP. We offer preventive surgery. We offer mammography as well.

[Karen Vecchio, Conservative, Elgin—Middlesex—London, ON]

Thank you so much, Dr. Narod.

I believe my time is up. I really appreciate that.

[The Chair, Liberal, Sean Casey]

It is indeed. Thank you.

Next we have Dr. Bennett, please, for six minutes.

[Carolyn Bennett, Liberal, Toronto—St. Paul's, ON]

Thanks very much to everyone.

I just have to say that, in a study on women's health, I hope that we will be able to move more broadly in terms of the social determinants but also in terms of women's responsibility as the health care provider for their families and the fact that we actually do need, I think, to look at the big picture.

I'd like to ask a question of Dr. Narod from Women's College. One of the things, I think, in women's health research is listening to women about what's worrying them. At the beginning, I think it was women worrying that their sisters or their nieces or their daughters were going to get breast cancer, and I think that obviously the discovery of the BRCA gene has been very important.

I would like you to tell us what you think the future would be in terms of cancer genetics and prevention, testing versus screening and how that could eventually move to treatment with precision medicine.

[Dr. Steven Narod]

Yes, that's a pretty good question.

I've been working on prevention. I've been working on screening. I've been working on treatment over the last 25 years. I was co-discoverer of BRCA1 and BRCA2. I've spent a lot of time thinking.

In 1991, when we did the first paper in The Lancet on BRCA1, I thought that, by the time we got to 2023, we'd have something better to offer than removing the breasts. So far, we don't. We just published a paper that using tamoxifen in several thousand women with BRCA1 mutations reduced the risk by about 20%. It's not really good enough.

I could talk all day about prevention. I'm not one who would think that we can tackle the breast cancer problem to a large extent in Canada by current preventive means. We recommend against alcohol. We recommend against obesity—weight loss, etc. Interestingly, for women under 40, being overweight is protective. No one ever talks about that, but it's very strongly protective.

Having worked in all three areas for 30 years, I would emphasize treatment. I think so. I mean, it's a matter of funding.

In terms of prevention, we have an idea of how we think we can do it, but it hasn't received funding yet.

I think a lot of the points made by the other speakers are valid. I do say though that, in our study, the end point was death. There were 500 deaths in one group and 505 deaths in the other group. I applaud Dr. Simard for his effort in trying to change it, but his study doesn't have death as the end point. None of the other studies have death as the end point.

You show me, Dr. Simard, that your program reduces the number of deaths, and I will be a convert to your program.

Interestingly though, Dr. Simard—I've been friends with him forever—is recommending a risk-based study rather than an age-based study. It's really interesting. Currently, the age base is 50 to 70. If we reduce the age base to 40 rather than 50, the genetic risk scores probably go out the window because, even for those people with a high risk score, the recommendation would be to start screening at 40 rather than 50.

Now, I heard all these things about outdated data for the national breast cancer.... Yes, it's outdated, but there are still 170 women who had breast cancer identified and are still alive. It doesn't mean.... You show me the current data. In my understanding, and having read every paper about it, I don't see any current data that supports using mammography to the extent to which the panel thinks it does.

One can talk anecdotally about this and that. The only other study that is always neglected to be mentioned is a U.K. age study done by Stephen Duffy and colleagues, published in 2022. It showed that, in randomized screening in the U.K., when women started at age 40 versus age 50—and we followed them until death or to age 60—it made no difference to the mortality rate, but you will never see that paper cited.

That paper was was written in 2020, and I've been communicating with Dr. Duffy. He actually gave me the information. You will never see the U.K. age study that actually showed that screening from age 40 was exactly the same outcome as screening from age 50.

[Carolyn Bennett, Liberal, Toronto—St. Paul's, ON]

You found that there were some mutations in the ethnically diverse populations. Do you think that mutation will affect the way different cancers or different patients are treated?

[Dr. Steven Narod]

Do you mean the mutations?

[Carolyn Bennett, Liberal, Toronto—St. Paul's, ON]

If it's a mutated cancer, will it take...? Once you find the genetics are different, then I presume the treatment might be different.

[Dr. Steven Narod]

Those are good questions. They're not really about screening, but you are 100% right.

I'm running an international study of 8,000 women with the BRCA1 mutation and collecting comprehensive information on their treatments. Dr. Simard published a paper two weeks ago in JNCI, which looked at BRCA1 and BRCA2 mutations in 2,500 women from many countries, including Canada. We are studying that. We do see that the treatments had different effects, certainly.

Nevertheless, I do believe preventing it is better than treating it. The best we can do with treatment.... My goal, as a physician working to cure breast cancer, is to get the survival rate to 90%. My goal, as a preventive physician working in screening, is to get the survival rate to 100%.

[The Chair, Liberal, Sean Casey]

Thank you.

Thank you, Doctor.

Ms. Larouche, you have the floor for six minutes.

[Andréanne Larouche, Bloc, Shefford, QC]

Thank you, Mr. Chair.

It's very interesting to hear what our witnesses are telling us this evening as part of this study. I think many of us have known people who have had breast cancer. I would like to take a moment to remember Nathalie, a friend who was diagnosed with breast cancer several years ago. She was in her late forties, and she passed away a few years later, just in her early fifties.

This cancer affects far too many women and takes them away from us far too soon. This brings me to the whole issue of screening and treatment.

Dr. Narod, you mentioned a study in Great Britain. That's interesting. A lot of questions have been asked by my colleagues about age and national guidelines, but what's happening internationally?

Mr. Simard, you are part of an international research group, so I invite you to comment on that as well. What could we learn from the work being done internationally?

Dr. Gordon, in your brief, you talk about statistics and data from other countries. What can these studies that are done elsewhere bring us here?

[Jacques Simard]

I'm fortunate to be part of an international consortium that studies data from 400,000 women in more than 35 countries on six continents. Thanks to these participants, we have been able to develop new tools to evaluate something called polygenic risk, which has been validated in more than a dozen prospective studies.

It should be noted that approximately one woman in 200 or 300 carries a mutation of a rare predisposition gene. So it's quite rare. We also studied the frequency of mutations in the BRCA1 and BRCA2 genes, which I was involved in discovering, in certain ethnic groups.

What we're proposing is the use of about 300 markers that are very frequent. By combining this signature with other risk factors, such as breast density, certain lifestyle patterns, and hormone factors, we could assess personal risk and stratify it into three groups.

For example, we followed 4,000 women in our study. Of these, 80% were at or near the same risk as the general population, 15% were at intermediate risk, meaning that they would have to start doing an annual mammogram at age 40, and 5% were at high risk. In their case, they should start doing an annual mammogram immediately, in addition to using magnetic resonance imaging, because there is indeed more than just mammograms. You know the statistics better than I do, but we know that 17% of all breast cancer diagnoses are made before the age of 50, so it's very important to take action.

Internationally, we are also working on risk prediction models or tools, such as genomic signatures, that are specific to various ethnic groups, such as Asians and Hispanics. It's very important.

[Andréanne Larouche, Bloc, Shefford, QC]

Thank you.

Go ahead, Dr. Gordon.

[Dr. Paula Gordon]

Thank you very much.

I'd like the committee to know how futuristic and wonderful Dr. Simard's work is, but it is futuristic. Certainly, Dr. Narod's discovery of the breast cancer gene was pivotal, but we're dealing with guidelines now that deal with average-risk women. Only 5% of women are high risk, and the vast majority of women who get breast cancer have no risk factors, not even a mother with breast cancer. In fact, having dense breasts is the most prevalent risk factor.

What the committee should understand—and I'm sorry to hear that Dr. Narod does not know this—is that the study with which Dr. Narod was associated, the Canadian national breast screening study, has been discredited. Although it was supposed to be a randomized trial, the randomization was flawed—corrupt you could say—and that explains why that study was the only randomized trial among eight others that did not show mortality reduction. We know why that study didn't show reduced deaths among women in the mammogram group.

For average-risk women, they should have a risk assessment. Right now, not all women can have the polygenic risk score that Dr. Simard spoke so well about, but women should be assessed for their risk. There are online risk tools that are free and easy to use, and average-risk women should start at age 40. If a women is shown to be at increased risk or at very high risk, she might start sooner, but otherwise, it should start at age 40 and, ideally, be annual because when women are premenopausal, the hormones made by their ovaries cause their breast cancers to grow faster.

That's why we must start screening women, especially Black, Asian and Hispanic women.... Indigenous women, in fact, have the same analogous inequities that we see for Black American women. They tend to get more aggressive cancers, and they're more likely to die from their cancers. Those inequities have to be addressed.

The other big inequity is for women with dense breasts. Now, that's something that no one can control. You can't control your breast density, yet women with dense breasts are more likely to get cancer, and we have a harder time seeing those cancers on their mammograms. We know that we can find them. We can find them with ultrasounds. If they're really high risk, we can find them with MRIs, but of course, MRIs are much more expensive and less accessible. It's not their fault that they have dense breasts. They deserve the same opportunity for early detection as women with non-dense breasts.

[The Chair, Liberal, Sean Casey]

Thank you, Dr. Gordon. That's our time for this round.

Next I recognize Mr. Davies, please, for six minutes.

[Don Davies, NDP, Vancouver Kingsway, BC]

Thank you, Mr. Chair.

Thank you to all the witnesses for being here.

Dr. Gordon, I'd like you to elaborate, please, on why breast screening guidelines, in your view, need to use inclusive and more modern evidence.

[Dr. Paula Gordon]

As you heard from Dr. Wilkinson, the Canadian task force procedures, to this point, have focused on rating the quality of evidence, if you will, and randomized control trials are always ranked the highest. The problem is that the randomized trials were all done between the 1960s and the 1980s, at a time when mammograms where done on X-ray film that you put on the light box. They are now done digitally, and we look at the images on a computer screen. They're much more accurate. We can use software, in fact, to help us decide whether a woman has dense breasts or not.

The old trials were done, as you heard, in white populations, so the guidelines discriminate against racialized women. Now, some people say, “Why don't you just do another randomized trial?” Because those old trials, even the flawed trials, prove that mammograms save lives, it would be unethical to repeat them and expect women to go in a control group that is not having any screening.

The newer observational studies.... The one this committee needs to hear about is one called the pan-Canadian study. It was published in 2014 and ignored by our task force. It looked at 2.8 million women having screening mammograms in our provincial screening programs, and it showed that, overall, women who have mammograms are 40% less likely to die than women who don't. It's even better for women in their forties; they're 44% less likely to die. However, the task force continues to use this old data, claiming that the randomized trials trump this new, modern observational data.

We have a natural experiment in the country, which you heard about from Dr. Wilkinson. Women who live in provinces that start screening at 40 are more likely to be diagnosed with early-stage breast cancer than women who live in provinces that start at age 50, and they have better survival. In provinces that don't screen until 50, the women in their forties are diagnosed more often with late-stage cancers than women in their fifties in the same province.

This is the outcome, and our task force has never audited the outcome of the current guidelines. The current guidelines are from 2018, but they are essentially unchanged since 2011. Dr. Wilkinson and colleagues, with Statistics Canada, were able to show the damage done by those guidelines. However, from what we can see, the current review under way is likely to come up with a recommendation for no change in those guidelines.

[Don Davies, NDP, Vancouver Kingsway, BC]

Dr. Gordon, one concern I've heard expressed is one of potential bias.

In May 2023, before the expedited review of the current guidelines had even started, Dr. Guylène Thériault, co-chair of the Canadian Task Force on Preventative Health Care, told the Toronto Star that she does not see any reason to change the task force's guidelines on breast screening, which means to keep it at the current age of 50. In addition, just this month, Dr. Thériault co-authored a journal article called “Debunking myths about screening”.

As a scientist, researcher and someone involved in this, what kind of confidence or lack of confidence does this give you that Dr. Thériault is able to fairly adjudicate based on the evidence?

[Dr. Paula Gordon]

She's clearly declared her bias and her conclusion.

You might be interested to hear that in that article called “Debunking myths about screening”, she claimed that earlier detection does not result in better outcomes. She said that's a myth. She said it's a myth that “newer technology produces more benefit”, and that it's a myth that screening saves lives.

I just told you that, from the pan-Canadian study, we know there are 40% fewer deaths in women who have mammograms.

[Don Davies, NDP, Vancouver Kingsway, BC]

Thank you. I understand that the United States has recently lowered the screening age to 40.

Is that right?

[Dr. Paula Gordon]

Yes. That's what's prompted this conversation. Normally the task force reissues its guidelines. The last couple have been every seven years. This has to be something....

Research is being churned out very quickly, and these guidelines have to be more nimble. They have to be able to be changed more frequently when more research is done.