Abstract 3805: Pre-diagnostic statin use among breast cancer patients - the relation to HMG-CoA reductase expression and disease-free survival

Abstract

Background: The purpose of this study was to investigate whether pre-diagnostic statin use was associated with tumor expression of HMG-CoA reductase (HMGCR) and disease-free survival (DFS) in breast cancer. Previous studies have shown anti-carcinogenic properties of statins and a significantly longer survival among breast cancer patients using statins. We recently showed, that the target of statins, HMGCR, was up-regulated in breast cancer among patients preoperatively treated with statins in a window-of-opportunity trial. Methods: A population-based cohort of primary breast cancer patients in Lund, Sweden was assembled between October 2002 and June 2012. Patients completed a questionnaire including information on medication use. Statin use in relation to DFS was analyzed in 985 patients. Tumor tissue microarrays were constructed and stained with a polyclonal HMGCR antibody to assess HMGCR expression (n=848). Results: Patients were followed for up to 11 years (median follow-up time 5.0 years). In the present study, pre-diagnostic statin use was neither associated with HMGCR expression (P=0.53) nor with DFS (P=0.92), overall or separately in any of the HMGCR expression groups (negative, weak, moderate/strong). Moreover, statin use was not associated with clinical tumor characteristics (tumor size, axillary lymph node involvement, histological grade, hormone receptor status or HER-2 amplification). Conclusion: In contrast to previous studies, the present study did not show any significant association between pre-diagnostic statin use and DFS. It is possible that patients who already used statins have developed tumors that are less dependent on cholesterol metabolism and consequently less influenced by statin treatment. The timing of statin use in relation to breast cancer diagnosis and prognosis should be evaluated in another cohort with preferably longer follow-up time. Citation Format: Helga Tryggvadottir, Emma Gustbée, Andrea Markkula, Maria Simonsson, Björn Nodin, Karin Jirström, Carsten Rose, Christian Ingvar, Signe Borgquist, Helena Jernström. Pre-diagnostic statin use among breast cancer patients - the relation to HMG-CoA reductase expression and disease-free survival [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3805. doi:10.1158/1538-7445.AM2017-3805