The chances of dying from breast cancer are greater in black women than white women, but other cancers do not show a survival gap between the races, according to two studies published online today in the Journal of the National Cancer Institute (JNCI).

In one study, researchers found a higher risk of death for black women among a group of nearly 250,000 women diagnosed with breast cancer from January 1990 through December 2003, especially in the first few years after diagnosis.

Dr. Idan Menashe, of the National Cancer Institute in Rockville, Maryland, and colleagues say these differences “may reflect racial differences in response and access to innovations in breast cancer treatment, as well as other biological and non-biological factors.”

But access to treatments may not explain all of the differences: In a related study on racial disparities in cancer survival published in JNCI today, a separate group of researchers reports that, even when black women with cancer get the same care as other patients, their survival rates are lower for breast, prostate and ovarian cancers.

In this study, Dr. Kathy S. Albain of Loyola University Medical Center in Maywood, Illinois, and colleagues identified more than 19,000 patients who participated in cancer clinical trials conducted by the Southwest Oncology Group and were followed for at least a decade after treatment. Twelve percent of the patients were black.

“In our analysis, the playing field was level,” Albain told Reuters Health: All patients had the same doctors and received the same state-of-the-art treatments.

Despite this equality of care, during the course of the study, African Americans were 49% more likely than other races to die from early postmenopausal breast cancer; 41% more likely to succumb to early premenopausal breast cancer; 61% more likely to die from advanced ovarian cancer and 21% more likely to die from advanced prostate cancer.

At the same time, survival rates were equal for other major cancers including lung cancer, colon cancer, leukemia, lymphoma and myeloma.

“Our findings dispel the myth that African Americans always do worse,” Albain said, “and that is really good news.”

“For most of the cancer types we studied, there was no disparity in survival. However, for the three cancers specific to one sex (breast, ovary, prostate), the disparity was there, despite the same treatment,” Albain said.

Thus, “access” is not the issue for these particular cancers, she explained. “Instead, there is something that ‘tracks’ with African ancestry only in these three diseases.”

That “something” potentially is an interaction between tumor biology, inherited gene variations that determine how the body handles toxins and drugs, and the physiologic hormonal environment, she explained.

“We most certainly are not talking about genetic inferiority here,” Albain emphasized. “If that were the case, then all 10 cancer groups in our study would have the disparity.”

SOURCE: Journal of the National Cancer Institute, July 7, 2009.