Outcomes after local recurrence following breast-conserving therapy for early-stage breast cancer.

66 Background: Limited data exist for patients who develop local recurrence (LR) following breast conserving therapy (BCT) for early stage breast cancer (ESBC). This study is to evaluate outcomes and predictors of failure following LR in patients treated with BCT. Methods: 1,654 women with ESBC underwent BCT from 1980 – 2013 at a single institution. All patients had breast-conserving surgery followed by whole breast irradiation (WBI) or accelerated partial breast irradiation (APBI). Subset analysis was performed for patients who developed LR as a first event. Clinical outcomes analyzed include contralateral breast failure (CLBF), regional recurrence (RR), distant metastases (DM), cause-specific survival (CSS), and overall survival (OS). Continuous variables were analyzed with an independent samples t-test and categorical variables with χ2. Univariate analysis was performed to determine factors predictive for events after LR. Results: 112 (7%) patients developed LR (87 WBI; 25 APBI), with median time to LR...