Salvage Mastectomy Versus Second Conservative Treatment for Second Ipsilateral Breast Tumor Event: A Propensity Score-Matched Cohort Analysis of the GEC-ESTRO Breast Cancer Working Group Database

Purpose Second conservative treatment has emerged as an option for patients with a second ipsilateral breast tumor event after conserving surgery and irradiation. We aimed to address the lack of evidence regarding by comparing oncologic outcomes or mastectomy. Methods Materials Oncologic were analyzed using propensity score-matched cohort analysis study on who received diagnosis between January 1995 June 2017. Patient data collected from 15 hospitals/cancer centers in 7 European countries. Patients offered mastectomy lumpectomy plus brachytherapy. Propensity scores calculated logistic regression multiple imputations. Matching (1:1) was achieved nearest neighbor method, including 10 clinical/pathologic related event. The primary endpoint 5-year overall survival salvage date. Secondary endpoints cumulative incidence third event, regional relapse distant metastasis, disease-free specific survival. Complications investigated cohort. Results Among 1327 (mastectomy, 945; treatment, 382), 754 matched score 377; 377). median follow-up 75.4 months (95% confidence interval [CI], 65.4-83.3) 73.8 CI, 67.5-80.8) respectively (P = .9). In analyses, no differences noted (88% [95% 83.0-90.8] vs 87% 82.1-90.2], P .6 2.3% 0.7-3.9] 2.8% 0.8-4.7], .4, respectively). Similarly, observed all secondary endpoints. Five-year 3.1% 1.0-5.1). Conclusions To our knowledge, this is largest combining brachytherapy events. Compared mastectomy, does not appear be associated any terms outcome. Consequently, could considered viable treatment.