MONDAY, Sept. 25 (HealthDay News) -- Despite similar treatments, black women with uterine cancer have higher death rates and shorter survival times than white women, new U.S. research shows.

Black women lived an average of 10.6 months compared to 12.2 months for white women with stage III, IV, or recurrent endometrial cancer, which is cancer of the uterine lining.

"African-American women with advanced endometrial cancer have worse outcomes than Caucasians even when they receive equal treatment," said Dr. G. Larry Maxwell, director of the Gynecologic Disease Center at Walter Reed Army Medical Center in Washington, D.C.

The study findings are published in the November issue of the journal Cancer.

Maxwell and his co-investigators performed a retrospective analysis of 1,151 patients -- 169 were black, 982 were white -- enrolled in one of four randomized treatment trials for advanced or recurrent endometrial cancer.

The analysis showed that black women had a 26 percent greater risk of death, compared to white women -- even if the stages of disease and treatments were similar. Blacks appeared to have lower tumor response to each of the chemotherapy regimens used in the trials, according to the study.

The study researchers looked at chemotherapy, surgery and postoperative radiation treatments. "Treatment in the general population may be a factor leading to differences in outcomes, but our findings suggested other factors need to be explored," Maxwell said. Those factors could include socioeconomic and cultural influences, he said.

The study is important because it "examines whether racial differences play a role in responses to chemotherapy and, most importantly, looks at survival in patients at high risk for recurrent endometrial cancer," said Dr. Robert Morgan, section head of medical gynecologic oncology at City of Hope cancer center, in Duarte, Calif.

The study authors looked at patients in clinical trials who received the same treatment. "This is the ideal setting to see differences in outcome with equal treatment. African-Americans have much worse survival even when we controlled for many prognostic variables that ultimately can affect survival," Maxwell said.

Morgan said the study findings "suggest that the difference in survival is biologic and that is consistent with what's reported with multiple other cancers."

There may be specific genes that mutate at different rates in tumors in blacks compared to whites, suggesting that biology -- not socioeconomic or cultural factors -- may explain the difference, Maxwell speculated. "Our group is looking at broader analyses of the entire genome," he said.

Morgan said the study findings suggest genetic causes for the differences between the races. "Although the authors hypothesize socioeconomic or cultural differences, in these well-controlled trials in which the populations are the same, I would be more inclined to believe there are biological differences," he added.

He said other studies have found differences in survival rates between races for other cancers, including breast, prostate and "a number of other" malignancies.

"This study looked at uterine cancer and shows more evidence for potential biologic differences between the races. We need to look for a scientific viewpoint focusing on genomic differences between racial groups," Morgan said.

Maxwell's group plans to do just that. It will be designing a prospective trial to determine whether genetic differences explain the disparity in survival.

In the end, however, another crucial message is clear, Morgan stressed. "The answer to patients is that early detection of endometrial cancer is almost always curative. Women of all races should know that if they have postmenopausal bleeding, they should see a gynecologist immediately. There is no normal postmenopausal bleeding," he said.

More information

To learn more about uterine cancer, visit the U.S. National Library of Medicine.