A retrospective comparative cohort study of SEER database analysis of the prognostic value of breast-conserving surgery and mastectomy in patients with multifocal multicenter breast cancer.

Background: The prognosis of multifocal multicentric breast cancer (MIBC) was related to many factors, and there are different recommendations for surgical approaches. We compare the effects of breast-conserving surgery (BCS) and mastectomy on the survival of multifocal multicenter breast cancer female patients.

Methods: A total of 38,164 female patients with pathologically confirmed multifocal multicenter invasive breast cancer from 2000 to 2018 in the Surveillance, Epidemiology, and End Results (SEER) database were extracted, and the effects of different factors on the survival of these patients were retrospectively analyzed. The patients were divided into a BCS group and a mastectomy group, and the differences of breast cancer-specific survival (BCSS) and overall survival (OS) were compared between the 2 groups.

Results: Of the 38,164 patients included in the analysis, 14,533 (38.08%) underwent BCS and 23,631 (61.92%) underwent mastectomy. Multivariate analysis showed that age, grading, staging, number of lesions, radiotherapy, and BCS would affect the independent factors of BCSS and OS in patients. The median follow-up time was 108 months [interquartile range (IQR): 64-162 months). Multifactorial Cox proportional model analysis of prognostic risk showed that BCS reduced BCSS in patients older than 70 years [hazard ratio (HR): 1.35; 95% confidence interval (CI): 1.2-1.53; P<0.001], stage I and II, positive hormone receptor (HR), all 2-3 lesions, no radiotherapy (HR: 1.46; 95% CI: 1.33-1.6; P<0.001) and no chemotherapy (HR: 1.42; 95% CI: 1.28-1.57; P<0.001); BCS also reduced OS in patients over 40 years of age, stages I, II, and IIIC, all molecular subtypes, all HR-positive or negative, 2-3 lesions, and no radiotherapy (HR: 1.38; 95% CI: 1.31-1.46; P<0.001) and no chemotherapy (HR: 1.36; 95% CI: 1.29-1.44; P<0.001) patients. Multivariate Cox regression showed that BCS is an adverse factor for BCSS [adjusted HR 1.2 (1.11-1.3), P<0.001] and OS [adjusted HR 1.24 (1.19-1.3), P<0.001].

Conclusions: In early, good prognosis, treatment-sensitive patients, there is no survival advantage for BCS and more BCSS and OS benefit for mastectomy patients.