Introduction: There has been little research on whether Contralateral Prophylactic Mastectomy (CPM) improves overall survival in patients with Hormone Receptor (HR) negative breast cancer. Our study aimed to determine whether CPM would bring survival benefits for the patients diagnosed with HR-negative breast cancer. Methods: All data were derived from the SEER database (version 8.3.6.1). We used LASSO regression analysis and stepwise regression method to screen the variables related to prognosis. The survival curves of breast cancer patients were drawn by the Kaplan-Meier method, and we used the Log-rank test to calculate statistical differences in survival curvesResults: The Overall Survival (OS) was significantly better for patients in the CPM group than the Non-CPM group, the pooled Hazard Ratio (HR) was 0.46 (95% CI: 0.14-0.78), multivariate Cox regression analysis after Propensity Score Matching (PSM) showed the same results, the CPM-group showed a significantly improved prognosis than the Non-CPM group, the pooled HR was 0.66 (95%CI:0.50-0.83), statistically significant. Conclusion: Our study confirmed that CPM could improve the prognosis of patients with HR-negative breast cancer and significantly extend overall survival. Simultaneously, clinicians should fully consider the advantages and disadvantages of the operation before performing CPM on patients to avoid patients’ decision regret.
