Hormone Therapy Linked to Breast Cancer in Blacks
Risk is higher in leaner subjects
TUESDAY, April 11 (HealthDay News) -- Hormone therapy is associated with an increased risk for breast cancer in black women, especially for those with a low body mass index (BMI), according to a report in the April 10 issue of the Archives of Internal Medicine.
Previous studies showing links between hormone therapy and breast cancer have largely included white subjects, but whether the link exists in other ethnicities is not clear. Lynn Rosenberg, Sc.D., of Boston University in Massachusetts, and colleagues used questionnaire data from 23,191 women at least 40 years old enrolled in the Black Women's Health Study from 1995 to 2003.
During the period, 615 cases of breast cancer were reported and occurred more often in women with recent hormone use, with risk increasing by number of years on hormone therapy. The risk for using either estrogen alone or estrogen and progestin for greater than 10 years was 1.58, but increased to 3.08 when the analysis was limited to women with a low BMI (less than 25).
The authors suggest that hormone pills may not impose a risk in heavier women because they already have high estrogen levels from a greater amount of adipose tissue. "These results based on data from U.S. black women strengthen the evidence that use of estrogen alone and estrogen with progestin increases the risk of breast cancer, and that the association is stronger among leaner women," they conclude.