Abstract 3724: Use of aspirin, other nonsteroidal anti-inflammatory drugs (NSAIDs), acetaminophen and risk of postmenopausal breast cancer

Abstract

Abstract Background Aspirin is widely used for cardiovascular disease prevention and has been consistently shown to be associated with a 20-30% lower risk of colon cancer. However, the associations between uses of aspirin, other NSAIDs, and acetaminophen and breast cancer incidence are uncertain. In addition, limited epidemiological studies have assessed these associations with breast cancer subtypes defined by hormone receptor status. Further, no known prospective cohort studies have been conducted on other clinical relevant subtypes including Triple-negative, Luminal A, Luminal B, HER2 positive, COX-2 negative and COX-2 positive. Design We followed 84,602 postmenopausal women, free of cancer in 1980, until June 2008. During this time, we prospectively collected data on analgesic use, reproductive history, and other lifestyle factors every two years. A Cox proportional hazard model was used to estimate multivariable relative risks (RRs) and 95% confidence intervals (CIs) by adjusting for age, reproductive factors and other important risk factors for breast cancer. Results A total of 4,754 pathologically confirmed incident invasive breast cancer cases were identified during 18 years of follow-up. Comparing with never use of aspirin, multivariable relative risks of regular aspirin use (at least 2 tablets/wk) for more than 20 years were 0.91 for overall breast cancer (95%CI: 0.81-1.01, P trend = 0.16), 0.90 for ER+PR+ breast cancer (95%CI: 0.77-1.06, P trend = 0.17), 1.03 for ER+PR- breast cancer (95%CI: 0.76-1.38, P trend = 0.94), and 0.92 for ER-PR- breast cancer (95%CI: 0.68-1.23, P trend = 0.98). Results did not vary substantially by past or current use, or frequency (days per week) of use. Use of other NSAIDs and acetaminophen also was not significantly associated with risk of breast cancer. Results were not changed after mutual adjustment for each of the drug. In addition, results were not modified by body mass index, alcohol consumption, family history of breast cancer, or postmenopausal hormone use. Further, no substantial associations were noted for other subtypes of breast cancer (ER-PR+, Triple-negative, Luminal A, Luminal B, HER2 positive, COX-2 negative and COX-2 positive). Conclusions Although a small reduction in breast cancer risk cannot be excluded, our study suggest that use of aspirin, other NSAIDs, and acetaminophen was not importantly associated with incidence of postmenopausal breast cancer overall or other specific breast cancer subtypes. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 3724. doi:10.1158/1538-7445.AM2011-3724