Oral contraceptives and breast cancer among African American women and white women

The higher incidence of breast cancer among African-American women younger than 50 as compared to white women points to the need to examine exposures that are common among younger women, including exposure to oral contracepti ves (OC). We examined patterns of OC use and their associations with breast cancer in a population-based, case-control study conducted in North Caroli na between 1993 and 1996. The study population was comprised of 858 cases a nd 789 controls, of whom 40% were African-American women. There was little evidence that breast cancer was associated with OC use among older women (a ge >50) of either race, most of whom discontinued use in the distant past. Among younger women, there was a modest, but nonsignificant, increase in ri sk associated with ever use of OCs for both African-American and white wome n. There was a trend of increasing risks with more recent use among African -American women, whereas no such trend was apparent for white women. Overal l, we found more substantial age differences than race differences in patte rns of OC use and the risk of breast cancer associated with their use. The similarity of the associations between African-American and white women sug gest that racial differences in breast cancer incidence are not likely to b e attributable to OC use.