The surgeon as the most important factor in lymph node harvest during axillary clearance

Current guidelines state that 10 or more lymph nodes (LNs) must be harvested in over 90% of axillary lymph node dissections (ALND), with the implication that 'more is better' during axillary surgery.

Our study included all consecutive patients from April 2010 - August 2011 at an NHS Trust (UK) who underwent ALND with the intention of clearing the axilla of LNs (level III). Data regarding harvested LNs were recorded in electronic patient records for each ALND operation. The names of the surgeon and reporting histopathologist were recorded, as well as data regarding preoperative neoadjuvant chemotherapy, prior sentinel lymph node biopsy (SLNB), and number of metastatic LNs. Statistical significance for continuous data was evaluated using unpaired t-test. Pearson correlation coefficient was used to assess the relationship between total number of LNs harvested and number of metastatic LNs.

A total of 232 patients underwent 237 ALND operations; 5/232 (2.2%) underwent bilateral surgery. The mean age (range) was 59.9 (32-94) years; the mean number of LNs (range) excised was 13.1 (0-35). The number of identified LNs was independent of whether the patient had undergone previous SLNB, or had received neoadjuvant chemotherapy. The number of LNs was independent of the histopathologist; however, there was a significant difference between surgeons (p<0.001). There was no statistically significant correlation between the total number of LNs harvested and the number of metastatic LNs harvested (r=0.301; p=0.297).

When auditing practice against guidelines for the treatment of the axilla in breast cancer, the surgeon undertaking ALND appears to be the only significant variable in affecting the completeness of dissection. However, the number of nodes harvested is unrelated to the number of metastatic nodes, challenging the idea that 'more is better' when it comes to axillary surgery.