Non-steroidal anti-inflammatory drug use and risk of adult leukemia.

Epidemiological studies have suggested that regular use of aspirin and other non-steroidal anti-inflammatory drugs (NSAIDs) may be associated with reduced risk of some types of malignancy. Leukemia incidence and self-reported aspirin, as well as other NSAID use, was examined in a prospective cohort of >28,000 postmenopausal women. Eighty-one incident leukemia cases occurred during the period 1993-2000. The multivariate-adjusted relative risk of leukemia was 0.45 (95% confidence interval: 0.27-0.75) for women who reported using aspirin two or more times per week compared with women who reported no use. Similar inverse associations were observed for the two subtypes of leukemia analyzed. In contrast, for women who reported using nonaspirin NSAIDs, the multivariate-adjusted relative risk of leukemia was 1.31 (95% confidence interval: 0.77-2.22). Analyses that excluded cases diagnosed before 1995 did not notably alter results. To our knowledge, this is the first prospective study to examine the association between NSAID use and incident adult leukemia. Although preliminary, the notable differences observed in leukemia risk between aspirin and nonaspirin NSAID use warrant further investigation.