Prescription drug use and risk of acute myeloid leukemia by French-American-British subtype: results from a Los Angeles County case-control study.

Chemotherapy is a well-established risk factor for acute myeloid leukemia (AML) but little is known about other prescription drugs and AML risk. We report data from a population-based Los Angeles County study in which 299 matched case-control pairs had complete data on prescription drug use and 88% of cases were subtyped according to the French-American-British (FAB) criteria. Cases were diagnosed between 1987 and 1994. Prescription nonsteroidal anti-inflammatory drug (NSAID) use for at least 4 weeks in the 2 to 10 years before diagnosis was associated with decreased risk (odds ratio = 0.5, 95% confidence interval=0.3, 1.0; p=0.04) with dose-response most evident for FAB subtype M2 (OR = 0.6, CI: 0.1, 2.9 for duration < or =6 months; OR = 0.2, CI: 0.0, 1.6 for >6 months). For subtype M4, ORs increased with increasing duration of benzodiazepine use in the 2 to 10 years before diagnosis (OR = 1.5, CI: 0.3, 9.0 for < or =6 months vs. OR = 5.0, CI: 0.6, 42.8 for >6 months). These results suggest that prescription drugs other than chemotherapy may have FAB subtype-specific effects on AML risk.