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Scholar Feature: Dr. Katherine Reeves Studies Breast Cancer Link from BPA

Katherine Reeves headshot

One aim of public health research is to uncover ways that our environment can impact human life, both positively and negatively. Strong, evidence-based research findings can inform policymakers and the general public about environmental toxins, that may have seemed harmless when they were first introduced, or ecological hazards that contribute to diseases or other negative health outcomes in humans. Research may be an intensive, complex and lengthy process, but the hope that it will eventually lead to significant changes in our environments and/or behavior, or spur legislation to help more people avoid health risks in the future, can be immensely rewarding.

For Dr. Katherine Reeves, a CRF Family Research Scholar in 2014-15, the recent public outcry over BPA, bisphenol A, misses a major part of the epidemiological story. “BPA has been taken out of baby bottles, children’s toys, children’s feeding products. For whatever reason, there hasn’t been that sort of advocacy surrounding adult products,” says Reeves. To address this knowledge gap, the research project she described in her successful FRS proposal focuses on the potentially harmful effects that long-term BPA exposure might yield in adults.

BPA appears in a wide range of consumer products—including food and beverage cans, water bottles, and the interior lining of potable water supply pipes. During her career in public health, Reeves has explored the contribution of modifiable factors on the incidence of breast cancer, including environmental factors. She has reason to believe that chronic, low-dose BPA exposure also represents a significant risk of promoting cancer development in women.

The long-term accumulation of BPA is problematic because it has been shown to disrupt the body’s normal hormone function. Additionally, the chemical structure of BPA is similar to diethylstilbestrol, a drug that was routinely given to pregnant women in the 1960s and 1970s to prevent miscarriage, though it is no longer used. Diethylstilbestrol, also known as DES, was later linked to a disproportionate number of vaginal cancers in children born to these mothers. As these women with in utero DES exposure age, there is some evidence that they may also be at increased risk of breast cancer.

According to Reeves, “We know that DES acts as a synthetic hormone, and we’ve seen that in BPA, too. We have data showing that it [BPA] interacts with an estrogen receptor. Estrogens, and estrogen signaling, are really well known for their importance in driving cancer and causing breast carcinogenesis.”

As a result of these preliminary findings, “in the next ten to fifteen years, we think we’ll see a lot more breast cancer associated with DES. And we’re worried that the same will occur with BPA.”

Although BPA has a short half-life of only six hours, research shows that prolonged exposure to low amounts—such as one might encounter in a daily can of soup—can spike BPA levels to almost 1,000% of the normal amount found in the urine. Epidemiologists like Reeves are concerned that such an acute level of BPA might lead to similar physiological effects as those that occurred with DES. “The difficult thing about BPA is that it’s leaching from these products into our diet. If you’re eating a can of soup every day, you never get down to zero,” she cautions.

While the general scientific community has expressed some uncertainty about the problems associated with low-grade BPA exposure, and the FDA recently upheld its continued usage in a variety of consumer goods, Reeves explains that several peer-reviewed studies have already linked BPA to increased cancer risk. “There are a lot of laboratory studies showing that BPA can make breast cancer cells grow. There are animal studies showing that BPA can cause mammary tumors or can cause changes in mammary glands.” These are the type of physiological changes that generally lead to an increased risk of breast cancer in humans.

If BPA is proven to increase estrogenic activity, Reeves hopes to advocate for responsible policy reform. “BPA is a case where policy has gotten ahead of the science. There is a lot of industry pushback. One of the things they say is ‘Well, this chemical is everywhere. If you’re measuring BPA levels, how can you be sure the samples are not contaminated?’” Investigative research holds the key, she says: “We can measure BPA in its metabolized form, which is a chemical change that can only happen when BPA passes through the body.”

To help bridge the knowledge gap about BPA’s potential link to breast cancer, she has proposed a pilot study of ten women that will begin in May 2015 that she is actively recruiting for now.* If the pilot goes well, Reeves will submit a grant to the NIH later this fall. “Within the next three to four years, we may have some understanding about whether this level of BPA exposure can cause a change in estrogenic activity,” she says.

While her study may not prove that BPA directly causes breast cancer, “it provides support for a mechanism by which it could, which will in turn justify future study of breast cancer” from BPA exposure. Of course, “it would be the best case scenario!” if it turns out that BPA does not create problems and her hypothesis is disproved, she laughs.

Dr. Reeves’s latest research is a natural outgrowth of her program of research across her career. Her previous and ongoing work to identify and understand breast cancer risk has included studies of other common products that women might encounter, such as phthalates (a chemical found in many plastics) and anti-depressants. Update (May 2015): Dr. Reeves's R01 $1.5 million research grant for the phthalates project was just funded by the National Institute of Environmental Health Sciences! Read more about her continuing work in this area here.

“It’s your mother or your daughter or your granddaughter or your grandmother. It really resonates with people. And BPA is something that does matter,” she says. “We should be thinking beyond what it might do to our children but also to ourselves, to adults.”

Since 2003, CRF has offered the Family Research Scholars Program, which provides selected UMass and Five Colleges faculty with the time, technical expertise, peer mentorship and national expert consultation to prepare a large grant proposal to support their research.

* Note: Recruitment for participants in the pilot study is now underway and more women are urgently needed! Email Dr. Reeves at kwreeves@schoolph.umass.edu to learn more.

Drew Thiemann, MPPA '16