Abstract:Objective To explore the prognostic factors of early breast malignant phyllodes tumor based on Surveillance,Epidemiology and End Results(SEER) database.Methods A retrospective analysis was made on the cases of early breast malignant phyllodes tumor with complete data records in SEER database from 2000 to 2015.The influence factors of overall survival were statistically analyzed.Kaplan-Meier estimator and Cox regression model were used to analyze the effect of surgery and radiotherapy on the prognosis of stage Ⅰ-Ⅱ patients.Results A total of 835 patients were included in this study.The median age of onset was 52 years old.Univariate analysis of stage Ⅰ-Ⅱ patients showed that patients with age≥70 years old (HR=2.32,95%CI:1.17-4.61,P=0.02) and low dedifferentiation and undifferentiation(HR=2.49,95%CI:1.52-4.08,P<0.01) had worse prognosis.The prognosis of total mastectomy group was worse than that of breast-conserving therapy group (HR=4.36,95%CI:2.55-7.46,P<0.01).The prognosis of postoperative radiotherapy group was worse than that of non-radiotherapy group (HR=1.86,95%CI:1.08-3.22,P=0.03).Multivariate analysis showed that the prognosis of total mastectomy group was worse than that of breast conserving group (HR=3.39,95%CI:1.93-5.97,P<0.01).Conclusion The local treatment of early stage breast cancer patients is recommended to receive breast-conserving therapy,and postoperative radiotherapy does not bring survival benefits.