BU Takes On Cancer: Racial Disparities
Genetics can trump income, access to care
In part one of a five-part series, BU Today examines the many ways BU researchers areworking to demystify, treat, and prevent cancer.
When epidemiologists Julie Palmer and Lynn Rosenberg launched the Black Women’s Health Study in the early 1990s, they could state with confidence the number of long-term health studies of African American women previously undertaken: zero. While it was clear that black women have higher rates of breast cancer at young ages, as well as a greater incidence of many illnesses, such as hypertension, diabetes, stroke, and lupus, scientists could only guess at the reasons.
Since then the national study has tracked the health of 59,000 African American women. The breast cancer conundrum in particular sent Palmer (SPH’85), senior epidemiologist at BU’s Slone Epidemiology Center and a School of Public Health professor of epidemiology, and her collaborators on the Medical and Charles River Campuses into the laboratory to probe the role of genetics and the nature of subjects’ malignancies. As data rolled in, the BU team began to uncover patterns of cancer and its outcomes in a population formerly neglected by good science. During their tenure with the study, Palmer and Rosenberg (GRS’65), Slone associate director and an SPH professor of epidemiology, have learned many counterintuitive things from this virtual community of willing, conscientious subjects. Chief among these is the discovery that cancers can behave differently in different populations, so the medical establishment needs to stop treating them as if they were the same.
The phrase cancer disparities refers to more than racial or socioeconomic gaps in access to cancer diagnosis and treatment. As it turns out, all other things being equal, race and ethnicity account for significant differences in the incidence and survivability of certain cancers and in how well people respond to standard treatments. For example, according to Palmer, cumulative findings from several studies indicate that, regardless of their incomes and how early they are diagnosed, African American women are more likely to die from breast cancer than their white counterparts. “At all ages mortality from breast cancer is higher for black women, and it’s clear now that it’s not due to differences in access, care, or treatments,” Palmer says.
As ambitious as it is, the Black Women’s Health Study is just one example of how BU has become a national leader in identifying, understanding, and working to correct cancer disparities, defined by the National Cancer Institute as differences in the incidence, prevalence, mortality, and burden of cancer among specific populations. In fact, the study of cancer disparities is “a distinguishing factor” of BU’s cancer research program, says Douglas Faller, director of the Boston University/Boston Medical Center Cancer Center and a School of Medicine professor and vice chair of the division of medicine. The program is a collaborative effort across campuses, spanning the fields of epidemiology, oncology, genetics, and public health. Historically lagging far behind other lines of inquiry, research in cancer disparities is making up for lost time—and lost lives—at BU.
But recruiting minority patients for research is not easy. At Boston Medical Center (BMC), researchers are conducting about 70 clinical trials involving a range of cancers, most under the umbrella of the Cancer Center. Among African Americans in particular, a historic, justifiable mistrust of the medical establishment (a result of a legacy of abuses, including the notorious Tuskegee syphilis study of the 1930s to 1972) is compounded by the rigors of the 20-page consent form (the primary language of 30 percent of BMC patients is not English) and the misguided notion among sick people that they might receive a placebo (in fact, studies compare experimental treatments with conventional treatment).
“The process scares cancer patients,” says oncology nurse Kathleen Finn, director of cancer clinical trials at BMC. But its practice of investing, as Finn puts it, one-on-one “time and respect” in patients, who are prescreened for eligibility, has rewarded BU with more than double the national rate of participation in cancer clinical trials.
“We have about 1,600 new cases diagnosed per year and about 9 percent of patients enrolled in a clinical trial, with 35 percent of those patients being minority,” says Finn. The national average is about 3 percent of patients diagnosed with cancer enrolled in a clinical trial and even lower for minority patients. And with the help of a 2010 minority-based $700,000 grant from the National Cancer Institute, Finn’s team is educating specially trained clinical navigators at greater Boston community health centers—a role combining that of educator and advocate—about clinical research and what it’s like to be in a clinical trial.
“Research is a moving target,” says Finn. “We’re small, but we’re special in that we understand the minority patient, and we stick with our patients from diagnosis through follow-up,” which can last 10 years. “We don’t give up on them.”
Black women and cancer
For the majority of participants, the Black Women’s Health Study, like its well-known counterparts, the Framingham Heart Study, begun in 1948 by the National Heart, Lung, and Blood Institute and run by BU since 1971, and the Nurses Health Study, ongoing since 1976, amounts to a lifelong commitment. Every six months, subjects receive newsletters that sum up recent study findings, include interviews with new staff, and offer straightforward information about diseases like diabetes and glaucoma. As part of the BWHS, Palmer and her team collect questionnaire data every two years, when they are asked about weight, diet, education level, lifestyle, pregnancies, and illnesses. If a subject reports cancer, the team seeks permission to get a pathology report from the women’s doctors. Over the last decade, 20,000 of the women have provided saliva samples for DNA testing of risk factors, including markers for breast cancer.
Participants answer questions about a long list of health conditions, and when respondents go missing after several cycles (each questionnaire draws about an 80 percent response rate) the team runs participants’ names through the National Death Index. The index provides information on the cause of death.
BWHS participants, whose mean age was 38 at the study’s start, are aging along with the study, and Palmer is now seeing occurrences of lung and colon cancers, the second and third most common cancers overall in women, as well as in breast cancer, the most common. Palmer’s team is in the process of investigating these cancers, but when it comes to breast cancer disparities, results have challenged the conventional wisdom about the disease and paved the way for improved treatment and survival among black women.
“The accepted wisdom about breast cancer and reproductive factors is that it’s good to have babies and the more you have, the lower your risk of breast cancer, and it’s good to have your first baby at a young age,” says Palmer. “But in our study we found that for young black women, having more births seems to increase the rate of an important subtype of breast cancer, which is more common in black women, and that finding has been replicated by other studies.”
Nearly 2,000 women in the BWHS have developed breast cancer, making it possible to analyze the cancers according to subtype, Palmer says. Breast tumors with estrogen—so-called estrogen-positive—have a better prognosis than estrogen-negative tumors. They can be treated by removing estrogen, in addition to chemotherapy, whereas chemotherapy alone is more toxic, Palmer explains. The BU study has shown that among black women, estrogen-negative cancer is twice as common (35 to 36 percent) as it is among whites (18 to 20 percent).
“My goal is to identify modifiable factors related to that cancer to reduce mortality,” says Palmer, adding that her findings also show that, sure enough, having more births reduced the risk of estrogen-positive cancers, but increased the risk of developing estrogen-negative breast cancers.
The next frontier has been made possible by a 2011 National Cancer Institute five-year, $19.3 million grant to BU and two partner institutions to study genetic and other risk factors for more lethal breast cancer types in African American women. It is a study of 5,500 African American women that will pool DNA data from the BWHS with data from the University of North Carolina Lineberger Comprehensive Cancer Center and the Roswell Park Cancer Institute in Buffalo, N.Y. Palmer and other investigators at BU will work with the partner institutions to identify environmental factors and pool information for genetic analysis—factors like number of births and breastfeeding. “I really think we’re going to find something interesting from that.”
Cancer prevention: spreading the message
The wealth of data from the BWHS encompasses far more than its compelling findings on breast cancer. For experts in cancer prevention and control, its trove of information on risk factors, from obesity to smoking, is a blueprint for other BU researchers who are trying to stop cancer in its tracks in minority communities.
“Julie’s work is a compass,” says Deborah Bowen, an SPH professor and chair of community and health sciences and a regional Cancer Prevention Network investigator. BWHS data reflect trends in a range of diseases and help direct the prevention network target risk factors, Bowen says. And here again, cancer disparities can defy logical assumptions; for example, black women tend to smoke less than white women, but the rate of lung cancer among both groups is the same, according to the American Lung Association.
The Cancer Center’s Cancer Prevention and Control in Diverse Populations Program has about 30 members who work in the field in teams of 6 to 10, particularly in Boston-area public housing, to screen residents for diabetes, high blood pressure, high cholesterol, and obesity and to help them quit smoking. They offer more than benevolent advice; Bowen is overseeing a smoking cessation program that gets National Cancer Institute funding to pay for nicotine gum or patches for low-income people who want them and to study the effectiveness of the approach. Increasingly, these programs are carried out by health navigators, residents of public housing themselves, who are trained in health screening and outreach.
One of these navigators, Janelle Pocowatchit, was on the grounds of the sprawling Charlestown public housing complex on a balmy March afternoon trolling for residents who might want to take advantage of Project Heart open house, a day of free health screening offered by SPH at the complex’s community resource center. “I love this kind of work,” says Pocowatchit, as she amiably approaches an elderly man in a tracksuit. “I take my blood pressure medicine, watch my diet, and walk every day, just like my doctor told me,” the man says.
Pocowatchit is a reminder that while BU’s epidemiologists crunch their numbers to find the causes of disparities in cancer and other diseases and community health researchers like Bowen reach out to populations who have traditionally been understudied and underserved, the picture is hopefully changing.
Tomorrow, in part two of “BU Takes On Cancer,” working to detect lung cancer earlier.1 Comments