In vitro studies showed that statins have antiproliferative, antiapoptotic, antiangiogenetic and immunomodulatory effect which prevent cancer growth. As a result of the published studies and meta-analyses, there were contradictory results with statin use on breast cancer risk, but the effect on clinical and pathological properties of breast cancer with statin use was not known exactly. In this study, we aimed to investigate retrospectively the effect of statin usage on clinico-pathological characteristics and recurrence risk of patients with invasive breast cancer.
Between 1998-2015 years from 4584 patients with invasive breast cancer patients who were taking statins at the time of diagnosis were enrolled as statin users (n = 164), where the patients matched with the same age who were not taking statin were included as a control group (n = 676). A total of 840 patients were included in this study.
The median follow up of patients was 73 months. Median age of both statin users and nonusers was 55 (36-86). There were no apparent differences in histological type, grade, axillary lymph node involvement, extracapsular extension, perineural invasion, lymphovascular invasion, menopausal status, HER2 positivity and hormonal receptor status between both groups. Treatment patterns such as hormonal treatment, chemothearpy and radiotherapy were similar. But non-significantly TNM stage 3-4 were seen lower in statin users group (26.4% vs 36.4%, P = 0. 09). In patients with statin users 5-year diseases free survival (DFS) rate was 85.1% whereas it was 74.7% and in nonusers (P = 0.02). The median estimated DFS was 221 months in statin users, whereas 175 months in nonusers. In patients with statin users 5-year overall survival (OS) rate was 92.3% whereas it was 84.6% in nonusers (P = 0.01).
Despite no clinicopathological difference between two treatment arms, statin usage improved both DFS and OS significantly. Thus our evidence suggests an alternative pathway for targeted therapy in breast cancer.
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All authors have declared no conflicts of interest.