Dr. Peggy Porter, head of the Breast Cancer Research Program at Fred Hutchinson Cancer Research Center, studies the molecular details of different types of breast tumors and the characteristics — such as age, ethnicity and environmental exposure — that can alter an individual’s cancer risk. With this information, she aims to help make breast cancer treatment more personalized and effective. We chatted with her about the importance of understanding the role that genetics and other factors can play in breast cancer, how a lack of comprehensive research has hampered access to treatment improvements among minority women, and how her research is designed to address this issue.
What are the goals of your research?
Outcomes are really what we’re concerned about. What is the outcome in every way: in survival, in preventing recurrence, in quality of life? We want high survivorship across all population groups.
We really have seen that the biology of genetic background related to race and ethnicity seems to play some part [in outcomes]. We showed, as many did, that African-American women have twice the rate of triple-negative breast cancer — the breast cancer subtype with no treatment targets and a poor prognosis — as Caucasian women. Hispanic women’s rate of triple-negative breast cancer is between that of black women and non-Hispanic white women.
The next step is figuring out what these differences mean, teasing apart what’s biology and what’s culture and socioeconomic disparities. Does biology tell us anything about how best to treat women from different populations?
What questions have you been asking in your research projects?
We’ve been involved in looking at tumor characteristics [in women from different ethnic backgrounds]. What are the characteristics of the tumor telling us about risk? What are they telling us about possible treatments? What is the relationship between tumor characteristics, breast cancer risk and potential treatments? We’ve tried to get as much data as possible out there.
We’re working with Dr. Beti Thompson in Public Health Sciences [at Fred Hutch], who studies inequities in our health care system, to look at the biomarkers of breast tumors in Hispanic women from New Mexico and Washington state. We’re asking how ancestry affects breast cancer subtype and presentation. We’re analyzing those data now.
We’re also collaborating with the University of New Mexico, New Mexico State University, and the International Agency for Research on Cancer, which is part of the World Health Organization, to look at the influence of ancestry on breast cancer subtype and tumor genetics. Right now we are working in five Latin American sites: Mexico, Colombia, Chile, Guatemala, Brazil, and Costa Rica.
What kinds of connections are you seeing between background and breast cancer?
We’re finding some differences in rates of breast cancer subtypes between countries, and that makes a lot of sense when you look at the ancestry of Latin American women. Indigenous, African, Anglo-European genes have all come together in different proportions. This could really change what an individual woman might be susceptible to and what her cancer might look like.
For example, African-American women have a high rate of triple-negative cancer, so a Latin American population that is much more African than indigenous in its ancestry mix — for instance, Puerto Rico — is likely to present with higher rates of triple-negative breast cancer.
We’re hoping to pull risk factor, genetics, and tumor characteristics together, not by grouping all Latin American women together, but by drawing conclusions based on country and ancestry.
The idea of tailoring cancer treatment to each individual is gaining a lot of traction right now. Are minority women getting included in this push?
Minority women have always been behind curve in terms of getting the benefit from medical advances. I look at the idea of personalized medicine as another important advance that certain populations will be slow to benefit from. It’s been true of early detection by mammography, of new treatment choices, and of inclusion in clinical trials.
We all know this. I think the push now has to be to make sure that the new advances in genetics, genomics, and personalized medicine really come to ALL women in this country and in other countries as well.
Why has knowledge lagged about minority women’s breast cancer risk, subtype, and outcomes?
Minority women and their tumors are often not included in big studies. For example, the last time we checked The Cancer Genome Atlas [a federally funded program cataloging genetic links to cancer], there were tumor samples from only 11 Hispanic women out of maybe 800 breast tumors. Most samples are from non-Hispanic white women. We and a number of people across the country are trying to correct that.
Knowing something about the population or the individual women that you’re going to treat is very important. But you can’t do it without data. That’s what we’re trying to provide with our studies.
How can researchers make sure they’re collecting much-needed data on breast cancer in minority women?
To get personalized medicine to minority women, studies have to be fully enrolled with all the ethnicities and races. They have to look at breast cancer subtype in the context of race and ethnicity. The studies need to try to understand whether risk factors, tumor characteristics and treatment responses differ by race and ethnicity.
We can get minority women into studies by educating patients and clinicians. There are ways to partner with other clinical trial sites and design trials that have diversity as a core component.
What is the current frontier in breast cancer?
If there’s one thing we’ve learned about breast cancer, it’s that it’s not one disease. Understanding the subtypes of breast cancer has been the probably biggest breakthrough in the years that I’ve been involved in studying breast cancer. We really do have a way now to identify characteristics of tumors that allow us to target treatment.
We need to continue the refinement of subtype until we can say ‘Yeah, we know how to treat you’ to any woman who comes into the clinic. We also need to better understand the risk factors associated with each subtype so we can develop and test new prevention strategies.