Why are African-Americans less likely to survive certain cancers?

Researchers followed more than 19,000 patients who were enrolled in cancer clinical trials conducted by the Southwest Oncology Group, a National Cancer Institute-funded clinical trials national cooperative. Patients of all races received the same advanced treatments by the same doctors.

"It was a level playing field for everyone, with the same quality care," said lead author Dr. Kathy Albain. "So our findings cast doubt on a prevailing theory that African Americans have lower cancer survival rates because of poverty, poor access to quality care or other socioeconomic factors." Albain is a breast and lung cancer specialist at Loyola University Health System's Cardinal Bernardin Cancer Center.

If poverty or other socioeconomic factors were to blame, then the survival gap should exist for all cancers. But the study, published in the Journal of the National Cancer Institute, found there was no statistically significant association between race and survival for lung and colon cancers, leukemia, lymphoma or myeloma.

"The good news for African Americans is that for most common cancers, they have the same survival rates as all other races," Albain said.

The cancers that did show survival gaps -- breast, prostate and ovarian -- are gender-related. The findings therefore suggest that the survival gap is due to a complex interaction of biologic factors in the tumor and inherited variations in common genes that control metabolism of drugs and hormones, Albain said. People with different patterns of these genes metabolize cancer drugs and their own hormones differently, and experience different side effects.

"We are actively conducting new research based on these findings to explore interactions among tumor biology, treatment, sex, race, inherited genes and survival," Albain said.

Dr. Patrick Stiff, director of the Cardinal Bernardin Cancer Center, said: "This groundbreaking study will provide investigators with a road map for future research that will improve outcomes of patients of all races and socioeconomic status."

Researchers identified 19,457 adult cancer patients enrolled in 35 Southwest Oncology Group clinical trials who were followed for at least 10 years after treatment. Twelve percent of the patients were African American. During the course of the study, African Americans were 49 percent more likely than other races to die from early-stage, postmenopausal breast cancer; 41 percent more likely to die from early stage, premenopausal breast cancer; 61 percent more likely to die from advanced-stage ovarian cancer and 21 percent more likely to die from advanced-stage prostate cancer.

Source: Loyola University Health System (news : web)