The value of intraoperative frozen section examination of sentinel lymph nodes in breast cancer.

BACKGROUND: Sentinel node biopsy is a standard diagnostic component for the treatment of patients with a primary mammary carcinoma. By concomitantly performing intraoperative lymph node biopsy and primary tumor resection, patients with a positive sentinel node (SN) are not subjected to the inconvenience and risks of second surgical intervention. The aim of this retrospective study was to determine the sensitivity, accuracy and long-term consequences of the frozen section (FS) examination of the SN in breast cancer patients.

METHODS: Sentinel lymph node biopsy was performed in 615 patients with an invasive tumor of the breast. Frozen sections of the SN were taken from the optimal cross-sectional surface. Serial sections were made from the remaining SN and stained using hematoxylin-eosin and immunohistochemistry.

RESULTS: Sentinel node frozen biopsy accurately predicted the state of the axilla in 559 (90.7%) patients. There were 50 false-negative findings in patients with sentinel node metastases. The sensitivity and specificity of the intraoperative frozen section examination were 71.6% and 100%, respectively. Follow-up (mean 36.3 months) of all false-negative cases showed no development of local axillary recurrence. The results demonstrated no significant relation between tumor size and frozen section sensitivity. Frozen section investigation was less sensitive in ascertaining micrometastases (sensitivity 61.1%) than macrometastases (sensitivity 84.0%, p<0.001).

CONCLUSION: Intraoperative frozen section examination of the sentinel node is a useful predictor of axillary lymph node status in breast cancer patients. Seventy-two percent of the patients with metastatic disease were correctly diagnosed and spared a second surgical procedure.