The relationship between post-diagnostic statin usage and breast cancer prognosis varies by hormone receptor phenotype: a systemic review and meta-analysis

Background Preclinical studies and epidemiologic data had indicated statins had antineoplastic properties in breast cancer patients. Since breast cancer treatment is based on its phenotype, it is important to explore influence of post-diagnosis statin usage on breast cancer patients with different phenotypes. Methods We searched the related studies between inception and August, 2019 from MEDLINE and EMBASE. A total of 7 studies with 24,541 patients were identified. Stata/SE 15.0 and Review Manager 5.3 were used to analyze data. Inconsistency index was used to estimate heterogeneity. Begg's and Egger's regression test was used to examine publication bias. Results Overall post-diagnostic statin use was associated with improved recurrence free survival (recurrence free survival (RFS); hazard ratio (HR) 0.74; 95% confidential interval (95% CI) 0.57-0.98), overall survival (overall survival (OS); HR 0.53; 95% CI 0.31-0.91) and cancer-specific survival (cancer-specific survival (CSS); and HR 0.61; 95% CI 0.41-0.91). In hormone receptor positive patients, statin use was associated with improved CSS (HR 0.74, 95% CI 0.65-0.84). No protective effect was found in either OS or RFS. In hormone receptor negative patients, statin was associated with reduced OS (HR 2.19, 95% CI 1.34-3.59) and reduced RFS, but without statistical significance. Conclusions Post-diagnostic statin use was associated with improved RFS, OS and CSS in breast cancer patients. Subgroup analysis indicted that the benefits of statin usage varied from hormone receptor phenotype type. Prospective randomized trial with patients of different hormone receptor types might be needed to help identify which subtype of breast cancer patients would benefit from post-diagnostic statin usage.

Automated summary

Post-diagnostic statin use was found to be associated with improved recurrence free survival, overall survival, and cancer-specific survival in breast cancer patients. The benefits of statin usage varied based on the hormone receptor phenotype, with potential harm in hormone receptor negative patients. Further prospective randomized trials are needed to determine the optimal use of statins for different subtypes of breast cancer patients.