Abstract 4678: Post-diagnosis use of lipophilic statins and breast cancer recurrence: A Danish nationwide cohort study

Abstract

Abstract Statins may affect non-cardiovascular endpoints, including cancer incidence and survival. These effects may depend on the solubility of the specific medicine. Our objective was to measure the association between post-diagnosis lipophilic and hydrophilic statin use and recurrence among non-metastatic breast cancer patients. We ascertained incident cases of stage I-III invasive breast cancer diagnosed in Denmark between 1996 and 2006 from the Danish Breast Cancer Cooperative Group registry, and linked these records to the Register of Medicinal Products (RMP), which automatically logs pharmacy transactions in Denmark. We determined statin prescriptions filled by cohort members by searching the RMP for appropriate ATC codes. Statins were classified by solubility (Table 1) and exposure status was updated yearly. Follow-up began upon completion of primary therapy and continued until the first of breast cancer recurrence, death from any cause, emigration from Denmark, or the end of 2006. Associations were estimated with time-dependent crude and multivariate Cox regression models. We enrolled 18,769 breast cancer patients, with a median follow-up of 6.2 years. Of the 3,282 women ever prescribed a statin after diagnosis, 2,518 were exclusively prescribed lipophilic statins and 210 were exclusively prescribed hydrophilic statins. Crude and multivariate models yielded similar estimates. Lipophilic (but not hydrophilic) statin use was associated with a reduced rate of breast cancer recurrence (compared with no statin use: multivariate HR for lipophilic statin use = 0.65, 95% CI: 0.55, 0.76; multivariate HR for hydrophilic statin use = 0.89, 95% CI: 0.61, 1.3). Associations were similar when estimated in the subset of women with no pre-diagnosis statin exposure. In this population-based prospective cohort study with complete information on prognostic and treatment variables, breast cancer patients who took lipophilic statins had a reduced rate of breast cancer recurrence. (a) Hazard ratios adjusted for age, menopausal status, tumor stage, ER status, adjuvant hormonal therapy, type of surgery, comorbidity, and co-prescription of aspirin. Estimates were similar in models further adjusted for chemotherapy, type of surgery, receipt of radiotherapy, and co-prescription of hormone replacement therapy, NSAIDs, anticoagulants and ACE inhibitors. 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 4678. doi:10.1158/1538-7445.AM2011-4678