Robert A. Hiatt, MD, PhD: Institute of Medicine Report (IOM) – Breast Cancer & the Environment

 

Dr. Robert A. Hiatt discusses the Institute of Medicine Report on Breast Cancer and the Environment: A Life-Course Approach, presented at the 34th Annual CTRC-AACR San Antonio Breast Cancer Symposium. The report urges a life-course approach to studying breast cancer because new information suggests that women and girls might be more susceptible to some risk factors during certain life stages.

Dr. Hiatt is the Director of Population Sciences and Associate Director of the Helen Diller Family Comprehensive Cancer Center and Professor and Chair of the Department of Epidemiology & Biostatistics at the University of California, San Francisco.

 

The Group Room at the 34th Annual CTRC-AACR San Antonio Breast Cancer Symposium was made possible by support from:

VIDEO TRANSCRIPT:

Selma Schimmel, Founder & CEO, Vital Options International:

Hello and welcome to the Group Room where we’re at the 34^th Annual CTRC-AACR San Antonio Breast Cancer Symposium. I’m very happy to be joined now by Doctor-Professor Robert Hiatt, who is the Director of Population Sciences and Associate Director of the Helen Diller Comprehensive Cancer Center. And he is Professor and Chair of the Department of Epidemiology and Biostatistics at the University of California, San Francisco. Welcome.

Robert A. Hiatt, MD, PhD, Dir. Of Population Sciences & Assoc. Dir. Of the Helen Diller Comp. Cancer Ctr, UCSF:

Thank you.

Selma Schimmel:

And you’re being talked a lot about here at the San Antonio meeting because of your very important work involving breast cancer and the environment which was done through the Institute of Medicine and truly many of the physicians we’re interviewing have commented on your work, and that’s what I would like to focus with you on today.

Robert A. Hiatt, MD, PhD:

Happy to talk about but it’s not me. It’s the committee – the IOM committee – that we will be channeling.

Selma Schimmel:

So let’s talk about why this is such an important piece of work, and the impact that’s going to have on our country and what we understand as far as risk factors and the environment.

Robert A. Hiatt, MD, PhD:

There was a broad overall conclusion and that was that we didn’t know enough about industrial chemicals and in particular, endocrine disrupting chemicals, which act like hormones and can have effects on synthesis metabolism that we thought were important. And we thought maybe the problem was the focus of research so far – at least in human populations has been on adult women – and you really can’t expect an adult woman to remember what kind of exposure she had when she was a child or earlier in her life, yet we feel there’s evidence that there are factors which influence breast cancer development and other sorts of development that are established early in life, maybe even in utero.

So one of the things the report stresses is the need to look at environmental exposures early in life. As a matter of fact, along the life course – that’s why the title is ‘breast cancer and environment in life course approach’ – so we think that the way forward is to measure exposures to environmental factors and windows of susceptibility during the life course. Windows of susceptibility are periods of times of open and shut in utero, pre-puberty, during puberty, age at first pregnancy, lactation, and menopause. All these times are periods when the breast is changing and potentially more susceptible to environmental agents of punitive nature.

But I want to frame what we learned in that context, so we’re saying the way to find out more is to look at the life courses approach, and that’s a strong message than as to what we can say now. We have identified a number of different factors.

One is medical ionizing radiation. We know ionizing radiation as distinct from non-ionizing radiation – I can clarify that if you wish – is a carcinogenic. We know this from the experience with the Japanese atomic bombs, we know this with the experience with medical radiation for tuberculosis treatment early in the century when doses were much higher. And the concern now is that there seems to be a lot more medical use of ionizing radiation for things like CT scans and other procedures, which may not be appropriate and if it can be cut down it would be a good thing in terms of overall risk because it’s cumulative exposure which is important.

We know that combined hormone therapy in estrogen that have been used by women post-menopausal is a carcinogenic.

Selma Schimmel:

Is the word ‘combined’ the important word here?

Robert A. Hiatt, MD, PhD:

Yes, it may be that the estrogen alone is not, for instance, a carcinogen-promoting substance, but the combination is, and we know this from the women’s health initiative.

We know that alcohol, even small doses can contribute to a slightly increased risk – it’s a clear fact. It’s not a huge risk but it’s there. We know that exposure to active smoking now is established. We know that increased weight is a risk factor for post-menopausal women, and we know on the other hand that the physical activity can be protective. These are the things we know.

And then we identified a number of circumstances or conditions or agents, which we think are possible. And they’re possible based on incomplete evidence so just to throw it out, BPA is one that’s on a lot of people’s minds these days. There’s increasing amount of evidence that this substance can act like a hormone and affect animal models in terms of early development. And there’s some very clear developing biology that has to do with genetics that my colleague, Cheryl Walker, just presented today that makes it biologically possible. But there’s virtually no human evidence that it has an effect, so we were not able to raise that to the bar that we had set for strong human evidence to make it an established risk factor.

Also, light at night, which is a phrase that reflects shift work, has been linked to breast cancer work, so this is something like nurses or service workers might be exposed to. We’re really not sure why, we’re not sure about the mechanism there but the eighth or so large epidemiologic studies that have shown an increase risk consistently with breast cancer. So it may be something to do with melatonin, a pineal hormone that’s sensitive to light, it has effects on hormones that could be a factor, we don’t know. So that fits in the biological possibility category.

We found that there needs to be more of a focus on early life and life course approaches, and we identified specific chemicals, specific substances, we’re able to categorize them into levels of risk.

Selma Schimmel:

So tell me, when a study like this comes out of the Institutes of Medicine – IOM – what happens now? What do they do with this, and how does this impact society?

Robert A. Hiatt, MD, PhD:

That’s a good question. So I think I have a pretty good answer for that and the IOM is not a funding agency and they don’t have the authority to change policy. But as you probably know the IOM is part of the National Academy of Science, which was founded under Abraham Lincoln’s presidency to provide independent, authoritative information to congress, originally, on matters of science. And over the years it’s developed so that other agencies can use the IOM for the same purpose, so Komen Foundation for the Cure.

So what you get from the IOM is an expert group knowledgeable in the area, selected very carefully who meet confidentially without influence from outside opinion, free to say whatever they feel is necessary to get at the science and they report a very heavily edited review report, and the members of the committee are sworn to secrecy for the rest of their days about what goes on in these committees. And that remarkably has been maintained. You don’t find members talking out of school, so it’s an important part of the process. So what does happen is that the IOM reports – because they are backed up by this process – are seen has highly authoritative, and agencies like the NIH, the CDC, the FDA, legislators, foundations, pay attention to them. And frequently policies will be made, or funding decisions will be made based on the IOM report, so I fully expect the Komen Foundation for the Cure will take this information as where we are now, and what we need to do next and use it for their own decision making.

Selma Schimmel:

I take this as a very empowering and positive way for people to begin to have a greater sense of control and responsibility in their lives. You may not be able to avoid easily, certain environmental risk factors but if you are conscious you can try to make choices and in that way be more engaged in how you live your life and why you make the choices you make.

Robert A. Hiatt, MD, PhD:

I think that’s certainly true but I would add to that in a sense…so let’s talk about stake holders. One stake holder is the individual who is empowered as you describe, another stake holder are those that are interested, not in themselves particularly, but in changing things at a policy level. So these are perhaps advocates, perhaps health policy individuals that take this information and use it to change regulatory or reimbursement issues. Another stake holder would be the funders, and they take information to make judgments about where to put their dollars for new research.

Selma Schimmel:

Well, in closing, what is your hope out of this body of work?

Robert A. Hiatt, MD, PhD:

I hope that will be used to refocus the search for environmental factors that influence breast cancer in a more sophisticated way in two ways. I hope that it will help us focus on the life course, and where environmental chemicals and substances which could be carcinogenic act, and that the appreciation that the matter is complex and interactive be incorporated into our thinking. We no longer are looking for one chemical or one cause, or one breast cancer outcome. Unfortunately it’s gotten more complicated, it’s not impossible to solve it’s just more difficult. And I hope we have a refocused way to do that.

Selma Schimmel:

Well thank you Doctor Hiatt. I’ve had the pleasure of meeting you before and I know you spent your entire professional life really dedicated to looking at these kinds of issues and trying to understand how we can live our lives in a better and healthier way. Professor Robert Hiatt, you are the Professor Chair of the Department of Epidemiology and Biostatistics, Director of Population Sciences, and Associate Director of the Helen Diller Family Comprehensive Cancer Center at the University of California, San Francisco.

END OF VIDEO