Intraoperative frozen section analysis of margins in breast conserving surgery significantly decreases reoperative rates: one-year experience at an ambulatory surgical center.

Intraoperative frozen section (FS) margin evaluation is not common practice for patients undergoing breast conservation therapy (BCT), but offers a significant reduction in reoperation. In this study, a technique to allow for more effective freezing of breast tissue was developed to perform FS evaluation of lumpectomy margins (FSM) for all patients undergoing BCT at an ambulatory surgery center. FS evaluation of sentinel lymph node biopsy specimens was performed concurrently. One hundred eighty-one study and 188 control patients, with and without FS evaluation, were compared. Reexcision was reduced 34% (from 48.9% to 14.9%) and reoperation was reduced 36% (from 55.3% to 19.3%) with FS evaluation. Most of the decrease in reoperative rate was because of a decrease in the need for margin reexcision. The number of patients requiring 1, 2, or 3 operations to complete therapy was 84, 92, and 12, respectively, in the control group, and 146, 33, and 2, respectively, in the study group. Lobular subtype, multifocal disease, and larger tumor size (≥2 cm) were significantly associated with failure of FSM to prevent reoperation, but reoperation rates were still significantly decreased in this subgroup of patients (from 75.5% to 43.8%) with FSM. This study highlights an innovative yet simple and adaptable FS approach that resulted in a nearly 3-fold reduction in reoperation for patients undergoing BCT.