Abstract 855: Medication use and ovary cancer risk in the California Teachers Study

Abstract

Abstract Background: Approximately 21,000 new cases of ovarian cancer are diagnosed in the United States each year. Because inflammation is thought to affect ovarian carcinogenesis, non-steroidal anti-inflammatory drugs (NSAIDs), including aspirin and ibuprofen, and other medications such as acetaminophen and histamine receptor antagonists, may affect the risk of ovarian cancer. However, existing epidemiological evidence on these associations is mixed. Methods: We assessed the relationship between medication use and risk of invasive epithelial ovarian cancer in the California Teachers Study (CTS), a prospective cohort of former or current female public school teachers and administrators in California. Analysis included 104,184 women, of whom 420 were diagnosed with invasive epithelial ovarian cancer during follow-up through December 31, 2007. Self-reported medication use from the baseline CTS questionnaire (1995-1996) was used to classify exposures. Relative risks (RR) and 95% confidence intervals (CI) were obtained using Cox proportional hazards methods. Results: Regular use, defined as at least once a week, of aspirin (RR 0.96; 95%CI 0.76 − 1.19), non-aspirin NSAIDs (RR 1.04; 95%CI 0.80 − 1.30), acetaminophen (RR 1.13; 95%CI 0.85 − 1.50) or histamine receptor antagonists (RR 0.85; 95%CI 0.58 − 1.20) was not associated with ovarian cancer risk. Ovarian cancer risk was not associated with daily use of aspirin (RR 1.04; 95%CI 0.77 − 1.45) or non-aspirin NSAIDs (RR 0.85; 95%CI 0.56 − 1.31) but was associated with daily use of acetaminophen (RR 1.82, 95%CI 1.01 − 2.95), and the latter association persisted after excluding ovarian cancers diagnosed during the first one to five years of follow-up. Two-thirds of the daily acetaminophen users also reported using acetaminophen for more than three years, but there was no association between increasing duration of use and ovarian cancer risk. Conclusion: Our results do not support the hypothesis that these medications reduce the risk of ovarian cancer. Conversely, the finding that daily acetaminophen use was associated with increased risk of ovarian cancer differs from previous studies and may warrant further investigation. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 855.