With each issue, Trib+Health brings you an interview with experts on issues related to health care. Here is this week's subject:
Robin Fuchs-Young is a professor in the Department of Molecular and Cellular Medicine at the Texas A&M University Health Science Center. Her research involves studying why some women are more susceptible to breast cancer than others.
Editor's note: This interview has been edited for length and clarity.
Trib+Heath: What made you interested in researching why some women are more susceptible to breast cancer than others, and why do you think it is an important subject to study?
Robin Fuchs-Young: I’ve been interested in breast cancer for a very long time, and the more I looked into it, the more I learned, the more I realized we really don’t know everything we need to know about susceptibility.
I came to this by looking somewhat at heath disparities. The thing that actually interested me the most was why women of African descent are more likely to die from breast cancer than women of European descent. On its face, that’s an important health problem, an important public health problem. And the more I dug into it the more I realized that it was a very interesting scientific and biomedical question because there are a lot of factors that play into it.
There’s socioeconomic factors, there are access to health care factors, there are all kinds of factors that lead into this or that that feed into this, but I’m interested in the biophysiological, molecular, genetic, epigenetic and environmental contributors to these heath disparities. I set about trying to understand the biophysiological, the biomedical contributors, but I acknowledge that there are a lot of sociologic, socioeconomic factors that also contribute.
Trib+Heath: What are some key factors that may determine why some women are more likely to get breast cancer than others?
Fuchs-Young: One of the things I was surprised by was how little we actually know about that. So we know, for example, that diet, body weight, the number of pregnancies early in life brought to term; we know that there are a variety of factors that include those but there are probably much more than those that can affect risks. We know there are inherited mutations in certain genes that can very substantially affect risk, but the inherited mutations that we know about represent a very small fraction of the risk factors. So we are very interested in understanding the risk factors better and understanding when and how they add to risk.
If we could really understand why some women are at greater risk than others, and why some women get the kind of breast cancer that tends to be a little bit more treatable, or a lot more treatable and much less aggressive, and why some women get the kind of breast cancer called triple negative that is both highly aggressive and fairly refractory to treatment, then at the end of the day what we ultimately want to be able to do is to prevent the disease.
Now that’s not the only place where research is needed. Obviously if somebody already has breast cancer, then we have to be able to treat it more effectively, and our work plays into that in some degree because we are interested in the mechanism by which breast cancer not only occurs but progresses. And so there’s a continuum of research from very, very basic to very, very applied, and they kind of feed together.
Our work, I hope, slides up and down that continuum. Where we’re very interested in our basic causes and contributors, we’re also interested in the translation of this to clinical medicine. In my career, I’ve spent some time looking at treatment.
Trib+Heath: In your research, are there any factors you’ve found that are maybe more likely to cause breast cancer in women than others?
Fuchs-Young: We don’t generally think in terms of absolute cause, because very rarely is there a single cause. I think that’s one of those things that is really important that we understand, is that cancer is a very complex group of diseases, and they have different kinds of causes.
The other thing is that these factors that can contribute to increased risk occur at different times in life. So some factors can make a contribution very early and some factors are more important later, and so we tend to study those factors that can occur very early in life. So we are looking at diet. We’re looking at the exposure to certain types of growth factors that can increase a women’s risk just as a result of variations from person to person within the production of certain growth factors. We look at diet. We look at genetic variations. We look at dietary variations.
Our recent work has focused on three main things. One is diet. One is insulin like growth factor-1 and one is a polymorphic variation in a gene called p53. We look at multiple contributors and we do a lot of work in vivo, [in animal models], because it allows us to understand a complicated group of [factors] that can all make a contribution.
I understand the desire to point to a thing and say, “That’s the cause. That’s it. If we can just do something about that thing.” But unfortunately that’s probably not the case. In reality, there’s a variety of things that make contributions over the course of a person’s lifetime, that ultimately end up affecting their overall lifetime risk.
Trib+Heath: Have you found any indication that certain groups of women as a whole are more likely to develop breast cancer than others?
Fuchs-Young: Well, it’s not just us. I think it’s really important that we all recognize that there’s a huge group of scientists all over the world researching this. So what we know is as a result of everyone’s work. It’s not what we’ve particularly discovered, it’s where the knowledge is at this moment. So we know, for example, that women of African descent have higher risk early in life. African-American women are more likely to develop what we call early onset disease at a younger age. White women of European descent are more likely to develop cancer post-menopause.
Our work, and the work of others, has indicated that diet and body weight, and fat and sugar, can play a role very, very early. We also have found that exposure to high levels of insulin like growth factor-1 early in life can change risk.
Trib+Heath: How do diet, body weight and exercise play into breast cancer risk?
Fuchs-Young: What we’ve found, and we are still looking at the mechanisms behind it, is that what seems to be important is the diet that someone is exposed to early in life versus the diet that they are exposed to later in life.
We did a study in mice where we looked at high fat, high sugar diets at different points in the mouse’s lifespan. We found that in mice that early exposure to high fat, high sugar diet, a highly caloric diet, followed by a mildly caloric or diet restriction later in life actually was protective.
Now we are looking at exercise or voluntary activity in these mice as well, but we don’t have the data back from that so I can't really speak about it. But we have found that the diet one has early and the diet one has late, in terms of fat and sugar, can have a profound impact on risk in mice.
Trib+Heath: How will this research on who is more susceptible to breast cancer impact how breast cancer is treated in different women?
Fuchs-Young: We’ve thought about that. If, for example, we find out that exercise changes risk; there’s a lot of research going on now to see what the impact of physical activity can be on risk both of the primary tumor and of recurrence. There’s some data out on that, but it’s not definitive. These are very difficult experiments to do.
So one could imagine how this information from these types of studies, combined with other types of treatment, could be used to reduce both the prevalence of breast cancer to start with and also the likelihood of recurrence. So it has the potential to fold into treatment.
Trib+Heath: Where would you like this research to go from here?
Fuchs-Young: We are now looking at the potential impact of various exposures on epigenetic variations, or epigenetic changes. This is something that was fairly recently discovered, where external forces and internal ones can change gene regulation without there having to be a mutation. There’s an entire field now of epigenetics, which is a mechanism whereby the environment, and in that I include diet, can affect susceptibility to a variety of diseases, including breast cancer. That’s sort of where our research is going.
Trib+Heath: Is there anything else you’d like to note?
Fuchs-Young: I guess the only thing is that, I think the good news is that there are a lot of people, a lot of scientists, working very hard to try to unravel these very difficult questions, and that we desperately need the support of the public.
So we hope that the public appreciates that these are difficult and timely and expensive experiments to do. But the good news is that there are a lot of really smart people trying to find out the answers so that they can be used to help people not only prevent breast cancer but treat it more effectively.