To investigate the clinicopathological features, metastasis and treatment of patients undergoing first diagnosis and postoperative surgery for stage Ⅳ breast cancer, and to explore the influence on prognosis.

The clinical data of 266 patients with stage Ⅳ primary breast cancer undergoing surgery for the first time admitted to two hospitals from February 2007 to December 2017 were retrospectively analyzed. Follow-up started at the time of diagnosis and ended at the time of death or December 31, 2020. Age, chief complaint time, first clinical T/N stage, metastasis, postoperative molecular marker expression, operation time, postoperative resection margin, vascular cancer embolus, postoperative pathological T/N stage and treatment were included to study the prognostic factors of patients undergoing surgery. Stata 15.0 software was used for statistical analysis. Log-Rank test was used for univariate analysis of prognosis, and Cox regression model was used for multivariate analysis of prognosis. P<0.05 was considered statistically significant.

Univariate analysis of prognosis: clinical N stage, first diagnosis metastasis, postoperative ER and PR expression, postoperative Ki-67 expression level, postoperative resection margin, postoperative pathological T and N stage and postoperative primary site radiotherapy were correlated with patients' OS (P<0.05). Multivariate analysis of prognosis: The first diagnosis of metastasis, the expression level of Ki-67 after surgery, the T and N stages of postoperative pathology, and the radiotherapy of the primary site were all independent prognostic factors affecting the patients' OS (P<0.05).

The postoperative pathological T and N stages of the patient were low, the oligometastases were stable at the first diagnosis, and the postoperative Ki-67 was less than 20%. The survival of the patient with radiotherapy in the primary site was more beneficial.