This article first was published in the Spring 2012 edition of the Association for Women In Science Magazine.

In 1995, when Lynn Rosenberg, Sc.D., Julie Palmer, and Lucille Adams-Campbell, Ph.D. began the Black Women’s Health Study (BWHS), the medical and epidemiological community already widely understood that African American women disproportionately suffer from a variety of medical conditions. In addition to being more likely to die from breast cancer, black women are three times as likely to develop uterine fibroids, Rosenberg explained. Lupus, scarcoidosis, preterm birth, diabetes, hypertension, and obesity are all more prevalent in the African American community, added Palmer. However, no one has been able to definitively address why this is the case.

Black Women and Breast Cancer

While African American women develop breast cancer at a lower rate than their white counterparts, it has become the most commonly diagnosed cancer among black women, and they seem to die from it more than any other race does. What could be causing this deadly disparity?

Researchers for the BWHS at Boston University’s Sloan Epidemiology Center think they just might have unraveled the answer and with it, a potential solution. B.U. Epidemiology Professor Julie R. Palmer, Sc.D., is a co-principal investigator for the BWHS. Palmer has devoted the better part of the past 20 years to understanding the causes of breast cancer among African American women. She explains that breast cancer comes in two varieties, estrogen-receptor positive, ER+, and estrogen-receptor negative, ER-. While the former can be treated with hormonal therapy, the latter and more deadly type requires intensive chemotherapy. This more aggressive ER- breast cancer is twice as common in black women as it is in white women. “That’s part of the reason why black women are more likely to die from breast cancer,” Palmer explains. The question remains, why is this deadlier variation more common in black women?

Among the 59,000 African American women enrolled in the BWHS, 1800 breast cancers have been diagnosed so far. Of those 1800 cases, investigators have been able to confirm and examine some 350 ER- cases.

Knowing that reproductive factors play a major role in the incidence of ER+ breast cancer, Palmer wondered if there might be a similar correlation between ER- breast cancer and reproductive history. She examined the reproductive histories of the 350 ER- women as reported in various questionnaires. In addition to categorizing women in the study by type of breast cancer, she and her fellow researchers looked at the women’s age at their first pregnancies, number of births, and history of breastfeeding. Comparison of all this data showed that women who had more than two children had about a 50% higher risk of ER- breast cancer than women who did not have any babies. However, further analysis indicated that this increased risk for ER- breast cancer did not occur in women who breastfed their children (1).

This revelation could have enormous implications for the breast health of black women if born out to be true in follow-up studies. “Breastfeeding might be a really important factor that is modifiable and that could be used to prevent breast cancer,” says Palmer. Currently, breastfeeding rates tend to be lower among African American mothers, which could explain why they are disproportionately developing—and dying from—ER- breast cancers. If further research corroborates this hypothesis, then a simple behavioral shift could have a dramatic impact on the long- term health of thousands of black mothers.

This Potentially Groundbreaking Finding Begs the Question: Why Has It Taken Us So Long To Find This Out? “Thirty or forty years ago, all the studies were of men,” said Rosenberg. “After that, all of the studies were of white men and women.” She saw black women’s health as a frontier in health care, one that had been overlooked with dire consequences.

With such little data available about this population, Rosenberg, Palmer, and Adams-Campbell decided to create a longitudinal cohort study in order to explore as many diseases as possible. The medical community had a lot of catching up to do in understanding how to best treat women of color.

It would be impossible to consider a large-scale study focusing specifically on an African American population without taking into consideration the infamous Tuskegee syphilis experiment. From 1932-1972, the U.S. Public Health Service, in conjunction with the Tuskegee Institute in Tuskegee, Alabama, studied 600 African American sharecroppers. Some 400 participants had syphilis, and in an effort to understand the progression of the disease, researchers monitored their suffering for forty years without offering any diagnosis or treatment. Outrage over this study led to stricter ethical standards for medical studies.

Rosenberg said that designing the study required some careful thinking about Tuskegee. Plans for communication with the study participants were carefully laid out. African American women were solicited to serve on an advisory board, including a physician who had investigated the history of medical research among African Americans in this country. Soon afterwards, two participants joined the advisory board.

One study participant, Jo-Anna Rorie, also a professor and a researcher at Boston University, but in a different department of the Black Women’s Health Study, said that she had run into fears stemming from the Tuskegee syphilis experiment in her own research. “Tuskegee is embedded in the memory of all communities of color.” As a participant in this study, she said that she had been impressed by the level of communication between the researchers and the participants and considered the BWHS to be a model for how information should be disseminated. As an individual study subject, she has taken some of the information included in the BWHS quarterly newsletters to heart. When a BWHS newsletter arrived in her mailbox suggesting that a stressful neighborhood could contribute to health problems, she started thinking about moving.

Black Women and Hypertension, Diabetes

For a variety of reasons, many African American women, regardless of income, tend to live in racially segregated urban neighborhoods. “We found that there was an effect over and above people’s individual behaviors, and we hypothesized that it may be the stress of living in an area where there’s more danger [that contributes to health disparities],” Palmer said. Add in the all-too-common coupling of a lack of fresh produce and an excess of fast food found in many low-income neighborhoods, and you have a recipe for diabetes.

“This cohort tends to be a middle class cohort, but we still live in low-income, sort of fringy kinds of neighborhoods,” said Rorie. “And that, in and of itself, might be causing a certain amount of stress that causes our blood pressures to go up.” Rorie, a successful researcher and professor with two master’s degrees and a nearly complete Ph.D., lives in Dorchester, Massachusetts, a largely working-class neighborhood of Boston with a reputation of high crime rates. As a controlled hypertensive at risk for pre-diabetes, she wondered if a change of scenery might be the needed prescription.

Another BWHS researcher, Patricia Coogan, Sc.D., a senior epidemiologist at Sloan Epidemiology Center, recently published in Circulation, a journal of the American Heart Association, further evidence that Rorie’s decision to move might be the right one (2). In a study of a subset of the BWHS cohort (those living in Los Angeles), she analyzed air pollution data and found a correlation between the common traffic pollutant, nitrous oxide, and incidence of diabetes and hypertension in black women. “It is well documented that African Americans tend to live in more highly polluted areas, and the incidence of diabetes and hypertension is much higher, twice as high in African American women [than in] white women,” said Coogan. She has secured funding from the National Institute of Environmental Health Science to look at this in the entire BWHS cohort.

Women in Epidemiology

Over the course of her career, Rosenberg has watched the field of epidemiology evolve and push the boundaries. When she applied for the doctoral program at the Harvard School of Public Health (HSPH), most people accepted into the program were male, medical doctors. She became one of the first women and biostatisticians to earn a doctorate in epidemiology at HSPH. Ten years later, Julie Palmer graduated from the same program along with two other women in a class of nine. Palmer said that today, the breakdown is closer to 50 percent female.

While Palmer suspected that in much of the field the professional demands on women made raising a family difficult, she found the leadership at Sloan (including Rosenberg and two male directors) fostered an environment compatible with motherhood. “I was fortunate to work in this group. The culture of this place is that family comes first and that you work when you’re at work and you don’t when you’re with your family,” she says. “Yes I would put in a 40-hour week, but I had all the rest of the time for family.”

However, BWHS is not just about women. “One thing that we’ve tried to do in this study, in addition to studying African American women, is to mentor African American scientists. It’s a long process moving up in the sciences, and it requires a lot of mentoring.” Palmer said that they had taken six to eight doctoral students from Boston University and Harvard under their wings. In addition, they mentored two junior faculty members and one postdoctoral researcher.

The Way Forward

In addition to making up for lost time and conducting research that should have been done long ago, the BWHS is pushing to bring knowledge of black women’s health into the 21st century.

In hopes of adding to the genetic data available for African Americans – currently most genetic data is from Europeans and Asians – Palmer has managed to secure DNA samples from more than 27,000 participants. Like all information gathered throughout the study, the samples were collected by mail. Participants used a relatively new technique to preserve their saliva samples; they swished with mouthwash and spit into a cup. The alcohol in the mouthwash acted as a preservative until the sample arrived at Sloan. Palmer plans to analyze the DNA samples in conjunction with data for incidence of breast and colon cancers, lupus, uterine fibroids, and sarcoidosis. Understanding genetic predispositions for these diseases could lead to additional treatments.

The daughters of BWHS participants are currently an untapped resource. Rosenberg said participants were surveyed to see whether they would consider having their daughters included in the study. “The response was not overwhelming,” she said. Palmer added that while it would be helpful to study a younger generation, current funding limits will not afford any expansion of the cohort. Because the study has many aims, funding must come from a variety of grants. Rosenberg and Palmer are trying to think creatively about how to push the study forward, always juggling the need to secure funding, design new studies, analyze data, and publish outcomes while hoping that women like Rorie, their daughters, and granddaughters will be better off.

Since forming the BWHS, Rosenberg, Palmer, and their fellow researchers have published over 100 articles in peer-reviewed journals examining the underlying causes heightened prevalence of a variety of health problems among African American women. With each paper, researchers shed additional light on a vastly understudied population. Palmer’s hypothesis that breastfeeding could reduce risk for estrogen-receptor negative breast cancer is one example of the potential benefits of widening this understanding. Coogan’s purported link between air pollution and diabetes and hypertension could be used to influence emissions policy and urban planning should the findings be confirmed. However, as with all scientific research, individual studies only reveal so much. Additional studies and independent research are needed to corroborate or disprove each finding.

References

1. Palmer, Julie R., et al. (September 2011). Parity and lactation in relation to estrogen receptor negative breast cancer in Afri- can American women. Cancer Epidemiol Biomarkers Prev 20(9): 1883-91. Available at http://www.ncbi.nlm.nih.gov/ pubmed/21846820

2. Coogan, Patricia F., et al. (January 2012). Air pollution and in- cidence of hypertension and diabetes in African American women living in Los Angeles. Circulation 125:767-772. Available at http://circ.ahajournals.org/content/early/2012/01/04/CIRCU- LATIONAHA.111.052753.abstract