Impact of axillary dissection in women with invasive breast cancer who do not fit the Z0011 ACOSOG trial because of three or more metastatic sentinel lymph nodes

AimThe objective of this study was to determine the effects of axillary lymph node dissection (ALND) versus sentinel lymph node biopsy alone (SLNB) on the survival of patients with 3 or more metastatic lymph nodes (MLN) in invasive breast cancer.MethodsData of 9521 patients with invasive T1-2M0 breast carcinoma and initial treatment with SLNB completed or not by ALND and 3 or more MLN were extracted from the SEER database. Univariate and multivariate analyses were performed.ResultsOverall, 9521 patients were included in the study. SLNB-alone compared with ALND did not result in different overall survival (OS) or specific survival (SS) for patients with 3 or more MLN (p = 0.46 and 0.58, respectively). In subgroup analyses, OS was comparable between SLNB-alone and ALND when patients had only 3 or more than 3 MLN. When patients had 3 MLN, the 5-year SS was significantly better for patients with ALND compared with SLNB-alone: 91.5% and 85.1%, respectively (p = 0.02). The Hazard Ratio (HR) for OS comparing SLNB-alone with ALND adjusting for age, adjuvant radiotherapy, tumor size, estrogen receptor status, grade and tumor type resulted in an HR of 1.05 (95% CI, 0.72–1.54, p = 0.77).ConclusionIn conclusion, patients with a T1–T2 invasive breast cancer and at least 3 MLN do not benefit from ALND after SLNB for specific and overall survival, thus limiting ALND to a staging procedure. A subgroup of patients with 3 MLN had a better SS with ALND, possibly due to an under-staging of the SLNB-alone group.