Will Targeted Axillary Surgery Suffice for Adjuvant Treatment Decision-Making?

Pichardo et al discuss the preplanned prospective observational cohort study by Weber and colleagues on the association of staging information gleaned from axillary lymph node dissection (ALND) with adjuvant systemic therapy treatment decisions in 2 groups of patients with breast cancer. This study is limited by its observational design, absence of a prespecified power analysis to optimize sample size, and low numbers of patients with hormone receptor (HR)-negative/ERBB2 (formerly HER2 or HER2/neu)-positive disease. This study also did not require a standardized approach to targeted auxiliary surgery: neither dual tracer nor localization of the clipped node was required, and type of tracer was not specified, limiting quality control assessments. Although we recognize this flexibility may enable generalizability of study findings to clinical settings in which axillary localization is not possible, these limitations raise questions as to the reproducibility of TAS as an alternative to ALND and its concomitant outcomes across different surgeons, institutions, and countries.