Modified Radical Mastectomy in De Novo Stage IV Inflammatory Breast Cancer.

BACKGROUND: There are few studies on surgical management in patients with de novo metastatic inflammatory breast cancer (IBC). The objective of this study is to examine the association between modified radical mastectomy (MRM) and disease-specific survival (DSS) in patients with de novo stage IV IBC.

PATIENTS AND METHODS: The Surveillance, Epidemiology, and End Result Program was queried for patients ≥18 years old with cT4d/pT4d pathology, histology type 8530 and 8533 with distant disease between 2010 and 2016. The sample was divided into two groups: (1) the MRM group, defined as MRM or mastectomy with at least ten lymph nodes removed, and (2) the no-surgery group. Sociodemographic and clinical variables were compared between the groups on bivariable analysis. After propensity score matching, Kaplan-Meier curves and a Cox proportional-hazards model examined DSS.

RESULTS: 1293 patients were included in the study, of whom 240 underwent MRM. A higher percentage in the MRM group had only one metastatic site (69.8% versus 52.2%), received chemotherapy (88.3% versus 66.1%) and radiation (58.8% versus 26.0%) compared with the no-MRM group. MRM was associated with an increase in DSS compared with no MRM [HR 0.63 (95% CI 0.50-0.80), p < 0.001]. Patients with MRM had a 5-year DSS rate of 31.4% compared with 17.7% for patients not undergoing surgery (p = 0.001). Survival time was 38 months (range 27-45 months) for the MRM group versus 27 months (22-29 months) for the no-MRM group.

CONCLUSION: MRM in patients with de novo metastatic IBC may improve DSS in a subset of patients.