BOSTON — Long-term use of nonsteroidal anti-inflammatory drugs other than aspirin may significantly reduce breast cancer risk in African American and Caucasian women, according to data from a multiethnic study.
Among women overall, however, no associations were seen between breast cancer risk and the use of aspirin or other nonsteroidal anti-inflammatory drugs (NSAIDs), Jasmeet Gill, Ph.D., reported at the annual international conference of the American Association for Cancer Research.
Previous studies looking at NSAID use and breast cancer have yielded mixed results, said Dr. Gill, a postdoctoral fellow at the University of Hawaii, Honolulu. “Although the relationship between cyclooxygenase-2 expression and breast cancer has been shown to be biologically plausible, the use of NSAIDs to reduce the risk of breast cancer is not well established,” she said.
Dr. Gill and her colleagues identified 4,010 incident breast cancer cases among American women who participated in the University of Hawaii/University of Southern California Multiethnic Cohort Study from 1993 to 2002, and reviewed NSAID exposure data gleaned from a self-administered questionnaire completed at baseline. The study includes African Americans, Caucasians, Japanese, native Hawaiians, and Hispanics from Hawaii and Los Angeles County.
Cox regression analyses showed no association overall between breast cancer risk and duration of aspirin use, other NSAID use for 6 or more years, or total NSAID use for 11 or more years. Neither were there consistent associations between medication use and breast cancer risk across strata of ethnicity, body mass index, tumor stage, or patient age, Dr. Gill reported in a poster presentation.
“The only associations observed were for other NSAID use among African American and Caucasian women,” she said. The use of NSAIDs other than aspirin for 6 or more years was associated with a 54% reduction in breast cancer risk among African American women and a 31% reduction in risk among Caucasian women.
“It is unclear why aspirin use was not associated with breast cancer risk reduction as has been shown in other studies, although we are intrigued by the reduced risk associated with other NSAID use in African American and Caucasian women,” Dr. Gill said. She had no financial disclosures related to her presentation.