It is a medical puzzle: Why are death rates for black men with prostate cancer almost 2.5 times the rate of white men in the United States?
Part of the reason is unequal access to health care.
But even that doesn’t fully explain the disparity, said Timothy Rebbeck, a professor of epidemiology at the Harvard T.H. Chan School of Public Health.
“It’s very clear you can minimize that difference or that disparity if you can get black and white men to have equal access to care, early intervention, and screening, but the effects don’t seem to entirely go away,” Rebbeck said Wednesday at a discussion of cancer disparities held at the UMass Club in Boston. Therefore, “there are probably biological differences that lead to more aggressive cancers in men of African descent in general.”
Understanding those biological differences is difficult, however, because many ethnic and racial groups are underrepresented in genomic studies and in the cell lines and clinical trials used to test new drugs, said Franklin Huang, an oncologist at Dana-Farber Cancer Institute.
“It’s a major challenge,” Huang said.
To address the gap, cancer researchers must first confront the lack of trust in the medical establishment that is felt in minority communities that have been historically mistreated by medical researchers, said Jill Macoska, director of the Center for Personalized Cancer Therapy at UMass Boston.
Such historical injustices include the notorious Tuskegee Syphilis Study, a research project that ran from 1932 to 1972 and involved hundreds of poor African-American men in Macon County, Ala., who were never treated for the disease, even after penicillin became the drug of choice for syphilis in 1947.
In another notorious case from the 1950s, researchers took cancer cells from Henrietta Lacks, a poor African-American woman, and cultured them without her knowledge or permission to develop a cell line, called HeLa, that became a vital tool of medical research. Lacks’ story was recently the subject of a major book and movie.
Macoska said some researchers are now working with churches and other groups to inform diverse communities about what happens to specimens donated for research and what the advantage are of participating in clinical trials.
Huang’s work looks specifically at disparities in prostate cancer deaths. He is taking tumors from Caribbean men with the disease, isolating the DNA, and then sequencing it to pinpoint the genes that are mutating and giving rise to the cancer.
He said he hopes to identify genes that are more commonly mutated in men of African ancestry than in men of European ancestry — a difference that could help explain the sharp disparity in death rates.
Others are trying to diversify the life sciences workforce.
People of color make up 30 percent of the US population, but just 12 percent of the nation’s science and engineering labor force, said Karen Burns White, deputy associate director of the Initiative to Eliminate Cancer Disparities at Dana-Farber.
White said she is seeking to recruit promising college students, expose them to research opportunities, and find them mentors who can guide them into medical and scientific careers.
Rebbeck said the National Institutes of Health and the National Cancer Institute are also trying to diversify cancer research.
He pointed to the NIH’s “All of Us” program, which aims to gather data on more than 1 million Americans to improve research and health outcomes.
“We should have been doing this 20 years ago,” Rebbeck said, “but at least there are large efforts trying to find out how to make this happen now, so we should be optimistic about what can happen in the future.”
The event, called “Cancer Disparities + Diversity in Life Sciences,” was presented as part of HUBweek, an innovation-themed festival sponsored by Harvard, MIT, Massachusetts General Hospital, and The Boston Globe.Michael Levenson can be reached at email@example.com