Regular use of analgesic drugs and ovarian cancer risk.

Analgesics have been shown to reduce risk for colorectal cancer. Results from three recent reports (D. W. Cramer et al., Lancet, 351: 104-107, 1998; C. Rodriguez et. al., Lancet, 352: 1354-1355, 1998; L. Rosenberg et al., Cancer Epidemiol. Biomark. Prev., 9: 933-937, 2000) suggest that these drugs might be associated with decreased risk for ovarian cancer. In this hospital-based case-control study, we compared 547 patients with ovarian cancer to 1094 age-matched patients with nonneoplastic conditions. All of the participants received treatment at the Roswell Park Cancer Institute between 1982 and 1998 and completed a comprehensive epidemiological questionnaire that included information on demographics, life-style factors, and reproductive characteristics as well as frequency and duration of aspirin and acetaminophen use. Women who reported that they had used one or more of these agents at least once a week for at least 6 months were classified as analgesic users. Logistic regression was used to compute crude and adjusted odds ratios (ORs) with 95% confidence intervals (CIs). Aspirin users were not at reduced risk of ovarian cancer compared with nonusers (adjusted OR, 1.00; CI, 0.73-1.39). There was also no evidence of a decrease in risk as a function of greater frequency of use or prolonged duration of use. Regular acetaminophen use was associated with a reduced risk (adjusted OR, 0.56; 95% CI, 0.34-0.86), and risk reductions were observed for women with the greatest frequency of use (adjusted OR, 0.32; 95% CI, 0.09-1.08) and longest duration of use (adjusted OR, 0.51; 95% CI, 0.27-0.97). These data suggest that regular use of acetaminophen, but not aspirin, may be associated with lower risk of ovarian cancer.