Concurrent Use of Statins in Patients Undergoing Curative Intent Treatment for Triple Negative Breast Cancer: A Systematic Review and Meta-Analysis

Pre-clinical studies in triple negative breast cancer (TNBC) suggest that statins may inhibit cell proliferation, promote cell-cycle arrest, induce apoptosis, change the tumor microenvironment, and improve effectiveness of other therapies. Observational studies have demonstrated variable effects from statin therapy on oncologic outcomes in these patients. As such, we aimed to pool previous data via a systematic review and meta-analysis to elucidate the impact of concurrent statin use on oncologic outcomes for patients with TNBC. Medline, EMBASE, CENTRAL, and PubMed were systematically searched from inception through to June 2022. Studies were included if they compared patients with TNBC receiving and not receiving statin therapy concurrently with oncologic treatment for curative intent in terms of recurrence and survival in a non-metastatic setting. The primary outcomes were 5-year disease-free survival (DFS) and 5-year overall survival (OS). A pairwise meta-analyses was performed using inverse variance random effects. Risk of bias was assessed with the ROBINS-I and the GRADE approach was conducted to assess quality of evidence. From 4014 citations, 5 studies with 625 patients on statin therapy and 2707 patients not on statin therapy were included. There was a significant increase in 5-year DFS for patients on statin therapy compared to patients not on statin therapy (OR 1.44, 95% CI 1.04-1.98, P = .03). No significant difference was noted in 5-year OS between the 2 groups (OR 1.12, 95% CI 0.86-1.47, P = .40). Included studies were at moderate-to-high risk of bias. The GRADE quality of evidence was very low. This review presents very low-quality evidence that concurrent use of statins with oncologic treatment may potentially improve long-term DFS for patients with TNBC undergoing curative intent therapy. Future research by way of large, prospective study is required to further clarify the clinical utility of statins on patients undergoing treatment for TNBC.