Frozen sections in patients undergoing breast conserving surgery at a single ambulatory surgical center: 5 year experience.

OBJECTIVES: To evaluate outcomes of our breast frozen section (FS) practice in its first 5 years, including our specialized FS of margins (FSM) procedure for breast conserving therapy (BCT) patients. METHODS: One thousand two hundred and forty eight patients undergoing 1303 breast FSM and/or sentinel lymph node (SLN) FS were included. Clinicopathologic features were assessed by chart review. RESULTS: Use of SLN FS declined, from 43.5% of FS cases before to 19.2% of FS cases after 2012. FSM patients had a decline in overall reexcision to 12.3% in 2013-2014 (p = 0.063). There was also decline in reexcision for focally close margins (p < 0.0001) but no change in reexcision for extensively close margins. Reexcision was significantly associated with lobular subtype, multifocality and larger (≥T2) size. False negative FSM cases were most often influenced by extensively close or positive final (reexcised) margins sent for permanent section only (96/148; 64.9%). CONCLUSIONS: Despite changing surgical practices, FSM remains a valuable service that reduces reexcision in BCT patients.