The value of the intraoperative assessment of the SLN via frozen section in the post Z0011 era.

Introduction: Sentinel node (SN) assessment via frozen section (FS) has declined since the publication of Z0011 which modified the management of a specific group of patients with positive SN. The risk of misleading the surgeons to a preventable ALND and the cost are among the main factors for that. The aim of our study is to assess the value of FS in the post Z0011.

Material And Methods: 244 patients out of 434 were eligible for an upfront SLNB. Based on the final histology and the clinical data we selected the eligible for breast conserving surgery patients (55.4%). 78 patients had positive SN and 26 of them fulfilled the criteria of Z0011. We assessed the false negative findings, the impact on the management and the indications and value of FS in the post Z0011 era.

Results: Overall, there were 12 FN cases out of which 7 were macrometastases (8.97%). Only in one case there were > 2 positive LN and 3 patients needed mastectomy. The remaining cases fulfilled the criteria of Z0011 and needed no further surgery hence in 96.1% of the cases the axillary status was correctly assessed via FS and the reoperation rate was 1.2%. On the contrary, if FS was not used, at least 21.3% of the patents would have needed reoperation based on the today's guidelines.

Discussion: We believe FS is still valuable and may spare a significant percentage of patients from a second operation (SNB) without leading to axillary overtreatment if used wisely.