Post-mastectomy immediate breast reconstruction is oncologically safe in well-selected T4 locally advanced breast cancer: a large population-based study and matched case-control analysis.

ABSTRACT

PURPOSE: Although it is well accepted that the survival outcome is most probably unaffected by immediate breast reconstruction (IBR) for T1-T3 tumors, the safety of IBR in T4 locally advanced breast cancer (LABC) remains unclear. METHODS: By using data from the Surveillance, Epidemiology, and End Results (SEER) database, the trend of IBR for female T4 LABC patients undergoing mastectomy, chemotherapy and radiotherapy was explored. The predictors of IBR in T4 LABC were evaluated by multivariate logistic regression. The survival outcomes were compared by means of Cox hazards models adjusting for known clinicopathological variables and stratifying on the T stage and contralateral prophylactic mastectomy (CPM). RESULTS: Altogether 714 cases underwent IBR between 1998 and 2015. The IBR cohort had a lower percentage of cases with T4d disease whereas higher percentage with CPM. The IBR rate was 10.1% and increased from 4.1% in 1998 to 17.7% in 2015. Since 2009, the rate of implant-based IBR exceeded that of the autologous tissue method. An age less than 45 years (OR 2.930, 95% CI 2.299-3.735) and CPM (OR 2.758, 95% CI 2.306-3.299) were the strongest predictors of IBR. In the 12 matched case-control analysis, IBR was not an independent prognostic factor for breast cancer specific-survival (BCSS) (HR 0.893, p = 0.236, 95% CI 0.741-1.077) and overall survival (OS) (HR 0.886, p = 0.183, 95% CI 0.741-1.059). BCSS and OS were similar among patients undergoing IBR whether they underwent CPM or not and whether they were inflammatory breast cancer (IBC) or not. CONCLUSIONS: IBR is oncologically safe in well-selected T4 LABC.