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Breast Cancer Disparities May Have a Biological Basis, Study Suggests

One of the most puzzling of all minority health disparities is that African-American women have a lower risk of developing breast cancer than white women yet are much more likely to die from the disease. The question of what could cause such a dramatic difference in mortality rates has engendered much debate in the medical community. Could there possibly be some biological or genetic difference that causes breast cancer to behave more aggressively in black women? A more likely theory, many experts believe, is that the disparity is due to socioeconomic factors, like poverty and racism, that prevent many black women from receiving timely, high-quality medical care.

However, the findings of a research study presented at the annual San Antonio Breast Cancer Symposium this past December have not only reopened this debate but also sparked controversy by suggesting that the biological/genetic theory may not be so far-fetched after all. The study of more than 6,500 women taking part in clinical trials of breast cancer drugs found that even when all other factors were equal--including income, education, age, body mass and tumor size--black women still had lower survival rates than all other racial/ethnic groups. Overall, the African-American participants were about 40% more likely to relapse or die than white women receiving the exact same treatment.

“It’s clear that other variables [besides sociodemographic factors] are involved,” says the study’s leader, Dr. Kathy Albain of Loyola University Medical Center in Maywood, Illinois. “It’s true that poverty is more prevalent among African Americans and access to good care is worse. But [our findings suggest that] even if you fixed all the other inequities, you still wouldn’t solve the problem.”

Albain adds that future studies of breast cancer disparities should focus on biological, genetic and epidemiological factors that might predispose African-American women to develop more aggressive types of breast cancer or respond differently to available treatments. A recent article in the Chicago Tribune reports that Albain’s research collective, Southwest Oncology Group, has begun looking for racial profiles in the gene signatures of tumors stored in its tissue bank and for racial differences in specific genes that metabolize drugs.

Still, some African-American health experts remain unconvinced by the Albain study’s findings. The Tribune article quotes Dr. Otis Brawley, former director of the Office of Special Populations Research at the National Cancer Institute, as saying, “The biggest reason for the disparity is not that the treatments don’t work in black patients, it’s that blacks don’t get the treatments. People are always looking for biological reasons, which allows [them] to accept the disparity and not look at the other reasons.”

For example, Brawley argues, many African-American breast cancer patients may get less than the full dose of chemotherapy or radiation because they can’t afford to take time off work, they lack transportation to get to the treatment facility or they have other illnesses that make the cancer treatment too toxic.