A 10-year trend analysis of sentinel lymph node frozen section and completion axillary dissection for breast cancer: Are these procedures becoming obsolete?

Background: Recent results from the ACOSOG Z0011 trial question the use of intraoperative frozen section (FS) during sentinel lymph node (SLN) biopsy and the role of axillary dissection (ALND) for SLN-positive breast cancer patients. Here we present a 10-year trend analysis of SLN-FS and ALND in our practice. Methods: We reviewed our prospective SLN database over 10 years (1997-2006, 7509 SLN procedures) for time trends and variation between surgeons in the use of SLN-FS and ALND in patients with cN0 invasive breast cancer. Results: Use of SLN-FS decreased from 100% to 62% (P < 0.0001) and varied widely by surgeon (66% to 95%). There were no statistically significant trends in the performance of ALND for patients with SLN metastases detected by FS (n = 1370, 99-99%) or routine hematoxylin and eosin (H&E) (n = 333; 69-77%), but only for those detected by serial section H&E with or without immunohistochemistry (n = 438; 73-48%; P = 0.0054) or immunohistochemistry only (n = 294; 48-28%; P < 0.0001). These trends coincided with an increase in the proportion of completion versus immediate ALND (30-40%; P = 0.0710). Conclusions: Over 10 years, we have observed a diminishing rate of SLN-FS and, for patients with low-volume SLN metastases, fewer ALND, trends that suggest a more nuanced approach to axillary management. If the Z0011 selection criteria had been applied to our cohort, 66% of SLN-FS (4159 of 6327) and 48% of ALND (939 of 1953) would have been avoided, sparing 13% of all patients the morbidity of ALND.