Does Race Affect Cancer Survival?
Breast Cancer Deaths Higher for Black Women Despite Equal Treatment
July 8, 2009 -- Black women have a lower incidence of breast cancer than white women, but once diagnosed they are more likely to die of the disease. Now, two new studies add to the debate about the roles that access to care and biology play in this disparity.
Poverty and inferior treatment could not explain the poorer survival among black breast cancer patients compared to whites in one of the studies because all the patients received the same treatments as participants in government-sponsored clinical trials.
Black trial participants were also more likely than whites to die of prostate and ovarian cancer, but they were no more likely to die of lung cancer, colon cancer, lymphoma, leukemia, or multiple myeloma.
“The big news here is that for the majority of cancers there is no survival disparity between blacks and whites when access to care is equalized,” lead researcher Kathy S. Albain, MD, of Loyola University tells WebMD.
The fact that this was not the case with the sex-related cancers suggests an important role for as yet unidentified biologic factors, Albain says.
Albain and colleagues analyzed data of nearly 19,500 cancer patients enrolled in 35 clinical trials overseen by the National Cancer Institute (NCI).
“We don’t know what it is, but we know in our study the difference (in mortality) wasn’t related to access to care,” she says. “How could it be access when the access was the same?”
Survival Poorer for Black Women With Breast Cancer
Black women are more likely than white women to have estrogen receptor (ER)-negative breast cancers, which are more deadly than ER-positive tumors.
But this biologic difference did not explain the survival advantage among white patients in either the Albain study or new research from the NCI.
Both studies appear in the July 15 issue of the Journal of the National Cancer Institute.
NCI researchers analyzed outcomes for nearly 250,000 breast cancer patients diagnosed between 1990 and 2004.
Black women were significantly more likely than white women to die of their disease, especially in the years immediately following diagnosis, regardless of their estrogen-receptor status.
“We believe this is mostly due to poorer access to care, but you can’t rule out the possibility that biology plays a role,” lead researcher Idan Menashe, PhD, tells WebMD.
American Cancer Society chief medical officer Otis Brawley, MD, tells WebMD that the Albain study is not the first to suggest that poorer access does not completely explain the higher death rate among black patients for sex-related cancers.
Factors Influencing Cancer Survival
But he does not accept Albain’s assertion that there must be genetic or biologic differences between black and white cancer patients that affect cancer survival.
He points out that death rates from breast cancer were the same for black patients and white patients until about 1980.