Efficacy of frozen section in sentinel lymph node biopsy in early breast cancer - An Australian single-centre experience.

Introduction: Sentinel lymph node biopsy (SLNB) is the standard of care for axillary staging in patients with clinically lymph node negative early breast cancer, reducing the need for axillary lymph node dissection (ALND) and its associated risks. Intra-operative frozen section is a method of rapid pathological assessment of the sentinel node to identify the presence of metastatic disease and potentially avoid the need for a second operation in patient who will require an axillary lymph node dissection. Methods: A retrospective review of a prospectively collected breast cancer database was performed. All patients with breast cancer who underwent SLNB and/or ALND at our institution, between May 1st 2017 to June 1st 2022 were identified. There were 565 patients who were included in the study. Results: Intra-operative frozen section was able to accurately identify 71% of patients who had macrometastasis in their sentinel lymph node, thus allowing them to immediately proceed to ALND and avoid a second operation. In patient who had a false negative frozen section result, only 6.5% required ALND. The majority of false negative results were due to isolated tumour cells or micrometastasis, and therefore would not have required further intervention. Conclusion: Intra-operative frozen section of sentinel lymph node biopsy in breast cancer is useful in reducing the need for a second operation, allowing staging of the axilla to occur more efficiently and with high diagnostic accuracy.