Association Between Acetaminophen or Nonsteroidal Antiinflammatory Drugs and Risk of Developing Ovarian, Breast, or Colon Cancer

Study Objective. To explore the association between exposure to acetaminophen (paracetamol) or nonsteroidal antiinflammatory drugs (NSAIDs) and risk of developing ovarian, breast, or colon cancer. Design. Retrospective case‐control study. Setting. General practice offices. Subjects. Four hundred eighty‐three women with ovarian cancer and 1877 women matched for age, years of medical history in computer record, general practice attended, and calendar time; 3706 women with breast cancer and 14,155 matched control subjects; and 635 women with colon cancer and 2434 matched control subjects. Intervention. United Kingdom‐based General Practice Research Database was searched for women aged 50–89 years with a first‐time diagnosis of ovarian, breast, or colon cancer and for matched controls to assess prescription analgesic exposure. Measurements and Main Results. Regular acetaminophen exposure (30 prescriptions) was associated with a slightly decreased risk of developing breast (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.7–1.0) but not ovarian (OR 1.0, 95% CI 0.6–1.5) or colon (OR 1.0, 95% CI 0.7–1.4) cancer. Regular NSAID exposure was associated with a reduced risk of colon (OR 0.5, 95% CI 0.3–0.9) but not ovarian or breast cancer. Conclusion. We found no evidence for a decreased ovarian cancer risk for women with regular acetaminophen or NSAID exposure.