Accuracy of intraoperative frozen section evaluation of sentinel lymph node biopsy in breast cancer: Our experience in Bahrain.

INTRODUCTION: Intraoperative frozen section of sentinel lymph nodes (SLN) in clinically node-negative breast cancer patients is performed to stage the axilla and allows axillary lymph node dissection (ALND) to be avoided in the same operative setting. The aim of this study was to evaluate our institutional experience on the accuracy of intraoperative frozen section of sentinel lymph node biopsy (SLNB) in breast cancer patients.

METHODS: Clinicopathological data from patients who underwent surgery for breast cancer with SLNB from January 2013 to May 2017 at Salmaniya Medical Complex (SMC) in Bahrain were collected retrospectively. Results of intraoperative frozen section were compared to paraffin section to determine accuracy, sensitivity, specificity, positive-predictive value (PPV), negativepredictive value (NPV) and false-negative rate (FNR).

RESULTS: A total of 104 patients with breast cancer underwent breast surgery with SLNB and intraoperative frozen section evaluation of SLNB. Frozen section correctly identified a positive or negative result in 97 cases (accuracy 93.2%). The sensitivity was 77.7%. The specificity was 98.7%. The PPV was 95.4%. The NPV was 92.6%. The overall FNR was 22.3%.

CONCLUSION: Our results show that intraoperative frozen section can reliably evaluate the status of SLNB in patients with breast cancer, allowing us to avoid second stage surgery in most women.