Number of lymph nodes identified at axillary dissection: Effect of neoadjuvant chemotherapy and other factors

BACKGROUND: Several reports have shown a significantly lower number of axillary lymph nodes (AxLNs) found at axillary lymph node dissection (ALND) after neoadjuvant chemotherapy. The objective of the current study was to investigate the factors affecting the number of AxLNs identified at ALND. METHODS: Medical records of patients seen at the study institution, a tertiary center, from 2004 to 2007 who underwent ALND for breast cancer were reviewed. RESULTS: Among the 698 patients who met study criteria, the mean number of AxLNs resected was 20.4. There were 649 (93%) patients with at least 10 AxLNs recovered. Seventy-one (10%) patients received neoadjuvant chemotherapy and 627 (90%) underwent surgical resection first. The mean number of AxLNs in the patients treated with neoadjuvant chemotherapy was 21.9 (range, 4-56 AxLNs) compared with 20.2 (range, 5-65 AxLNs) in the group treated with surgical resection first (P=13). The number of patients with <10 AxLNs found at ALND was 44 of 627 (7.0%) in the surgical resection first group and 5 of 71 (7.0%) in the neoadjuvant chemotherapy group (P=1.0). The mean number of AxLNs was higher in the 599 (86%) ALNDs performed at the study center compared with the 99 cases from outside institutions (21.2 vs 15.2 AxLNs; P <.001). Among the cases performed at the study institution, 367 (61%) were performed by surgeons with oncologic training and 232 (39%) were not. Surgical oncologists recovered an average of 23 AxLNs, which was significantly higher than the 18.4 resected by the remaining surgeons (P <.001). CONCLUSIONS: The number of AxLNs recovered at ALND does not appear to be affected by neoadjuvant chemotherapy. Surgeons with oncologic training appear to retrieve more AxLNs.