Radiotherapy Improves Survival In Patients With Stage Ⅳ Breast Cancer After Chemotherapy And Surgery

Background Role of radiotherapy for stage Ⅳ breast cancer remains controversial now.Therefore,we aimed to retrospectively investigate whether radiotherapy would improve the breast cancer-specific survival(BCSS)and overall survival(OS)for patients with stage Ⅳ breast cancer who received both chemotherapy and surgery,using the Surveillance,Epidemiology,and End Results(SEER)database.Patients and Methods A total of 1,211 eligible patients with stage Ⅳ breast cancer diagnosed between 2010 and 2012 were selected from the SEER database.We divided those patients into radiotherapy and non-radiotherapy groups.Kaplan-Meier analysis were computed to generate the survival curves and cox proportional hazard regression models to assess the prognostic factors and survival outcomes of stage Ⅳ breast cancer patients.Results In this study,610(50.37%)patients underwent radiotherapy,while 601(49.63%)patients did not.The median survival time of radiotherapy group versus non-radiotherapy group were 33 and 28 months,respectively.Both Kaplan-Meier and multivariate survival analysis showed that radiotherapy group presented with better prognosis than non-radiotherapy group(BCSS,hazard ratio(HR)=1.599,95%CI:1.330-1.923,P<0.001;OS,HR=1.572,95%CI:1.317-1.876,P<0.001).Furthermore,when stratified according to breast subtype,type of surgery and status of distant metastases,radiotherapy is associated with promising BCSS and OS except for HER2 positive patients.Conclusions Radiotherapy is associated with improved survival in patients with stage Ⅳ breast cancer.Therefore,we argue that radiotherapy may be the best complementary therapy for stage Ⅳ breast cancer patients who have undergone chemotherapy and surgery.