PC20. LONG-TERM CANCER RECURRENCE RATES FOLLOWING NIPPLE-SPARING MASTECTOMY: A 10-YEAR FOLLOW UP STUDY

Abstract

PURPOSE: Although nipple-sparing mastectomy (NSM) is a widely accepted and popular technique, limited data exists examining long-term cancer recurrence rates associated with it. This study sought to analyze rates of breast cancer recurrence in patients who underwent therapeutic NSM with a median of 10 years of follow-up. METHODS: A single institution retrospective review identified all patients who underwent NSM with a median of 10-years of follow-up. Analysis focused on patient demographics, mastectomy specimen pathology, and oncologic outcomes including cancer recurrence. Independent risk factors for locoregional recurrence were assessed via univariate logistic regression. RESULTS: 158 therapeutic NSMs were performed on 152 patients. Invasive ductal carcinoma (48.7%) and ductal carcinoma in situ (35.4%) were the most common tumor types seen on pathology. Multifocal/multicentric disease and lymphovascular invasion were present in 34.1% and 12.8% of specimens, respectively. Sentinel lymph node biopsy rate was 82.9%, with 15.2% reported as positive. Rates of positive frozen and permanent subareolar biopsy were 5.4% and 8.3%, respectively. Low cancer stages were overwhelmingly more common, with stage I and stage 0 representing 40.5% and 35.4% of the population, respectively. Incidence of recurrent disease was 3.2% per mastectomy and 3.3% per patient. Univariate analysis did not identify any variables that were independent risk factors for locoregional recurrence. CONCLUSION: At a median of 10 years of follow-up, overall cancer recurrence rates are low in patients who undergo NSM, further suggesting the safety of this technique. Regardless, close surveillance should remain a goal to ensure prompt detection of any sign of recurrence.