Age and Receptor Status Do Not Indicate the Need for Axillary Dissection in Patients With Sentinel Lymph Node Metastases

Abstract

Background

ACOSOG Z0011 demonstrated the safety of omitting axillary dissection (ALND) in women with <3 positive sentinel lymph nodes (SLNs) undergoing breast-conservation therapy (BCT). Since most were postmenopausal with ER-positive cancers, applicability to younger patients or those with triple-negative (TN) or HER2 overexpressing (HER2+) tumors remains controversial.

Methods

From 8/2010–12/2015, patients undergoing BCT for cT1-2N0 disease and found to have positive SLNs were prospectively followed. ALND was indicated for >2 positive SLNs or gross extracapsular extension. Clinicopathologic characteristics, axillary surgery, nodal burden, and outcomes were compared between high-risk (TN, HER2+, or age<50 years), and the remaining patients, termed average-risk.

Results

Among 701 consecutive patients, 242 (35%) were high-risk: 31 (13%) TN, 48 (20%) HER2+, 130 (54%) age<50, and 33 (14%) >1 high-risk feature; 459 (65%) were average-risk. High-risk patients were younger, with higher-grade tumors (p<0.0001), and more often had abnormal nodes imaged (p=0.02). SLNB alone was performed in 85% high-risk vs. 82% average-risk cases (p=0.39): median 4 vs. 3 SLNs excised (p=0.04), and median of 1 positive SLN in both groups. 62% high-risk vs. 65% average-risk (p=0.8) had additional positive nodes at ALND, with a median of 3 positive nodes in both groups. At median follow-up of 31 months, there were no isolated axillary recurrences.

Conclusions

ALND was no more likely to be indicated in high-risk patients. In patients undergoing ALND, nodal burden was similar. ALND is not indicated based upon age or subtype in patients otherwise meeting Z0011 clinical eligibility criteria.