Background: Recent studies suggest that surgical lymph node (LN) evaluation may be omitted in select elderly breast cancer patients as it may not influence adjuvant therapy decisions. To evaluate differences in adjuvant therapy receipt and overall survival (OS), we compared clinically node-negative (cN0) elderly patients who did and did not undergo axillary surgery.
Methods: Patients aged ≥70 years in the National Cancer Database (2004-2014) with cT1-3, cN0 breast cancer were divided into two cohorts-those with surgical LN evaluation (one or more nodes removed) and those without (no nodes removed). Propensity scores were used to match patients based on age, year of diagnosis, tumor grade, cT stage, estrogen receptor status, and Charlson-Deyo comorbidity score. A Cox proportional hazards model was used to estimate the effect of LN surgery on OS.
Results: Overall, 133,778 patients were matched, of whom 102,247 patients (76.4%) underwent nodal surgery. Patients undergoing nodal surgery were more likely to receive chemotherapy (pN1-3: 22.2%; pN0: 5.8%; cN0-no nodal surgery: 2.8%; p < 0.001), radiation (pN1-3: 49.7%; pN0: 47.5%; cN0-no nodal surgery: 26%; p < 0.001), and endocrine therapy (pN1-3: 72%; pN0: 58.5%; cN0-no nodal surgery: 46.5%; p < 0.001). After adjustment for known covariates, patients who did not undergo nodal surgery had a worse OS (hazard ratio 1.66, 95% confidence interval 1.61-1.70).
Conclusions: For elderly cN0 breast cancer patients, axillary surgery was associated with higher rates of adjuvant therapy and improved OS. A selective approach to omitting nodal surgery should be considered in elderly patients with cN0 breast cancer as axillary staging may influence subsequent treatment decisions and long-term outcomes.