Association of LN Evaluation with Survival in Women Aged 70 Years or Older With Clinically Node-Negative Hormone Receptor Positive Breast Cancer

Background. Some suggest that lymph node (LN) evaluation not be performed routinely in women aged >= 70 years with clinically (c) LN-negative (-), hormone receptor (HR)-positive (+) breast cancer. We sought to determine the association of omission of LN evaluation on survival. Methods. Patients who met the above criteria and were diagnosed from 2004 to 2012 were identified in the NCDB and SEER databases. Overall survival (OS) and breast cancer-specific survival (BCSS) were determined. Results. Using the NCDB, we identified 157,584 cLN- HR+ patients aged >= 70 years in whom survival and LN evaluation data were available. A total of 126,638 patients (80.2%) had regional LN surgery. With a median follow-up of 41.6 months, there was a significant difference in OS between those who had LN evaluation and those who did not (median OS: 100.5 vs. 70.9 months, respectively, p < 0.001). After adjusting for patient age, race, insurance, income, comorbidities, tumor characteristics and treatment, patients who had undergone LN evaluation still had a lower hazard rate for death than those who had not (hazard ratio = 0.633; 95% confidence interval [CI] 0.613-0.654, p < 0.001). We then did a parallel analysis using SEER data that showed LN evaluation was associated with a lower hazard rate for both BCSS (hazard ratio = 0.452; 95% CI 0.427-0.479, p < 0.001) and non-BCSS (hazard ratio = 0.465; 95% CI 0.447-0.482, p < 0.001). Conclusions. Roughly 20% of patients older than aged 70 years with cLN-, HR+ breast cancer did not have LN evaluation. Those who did had better OS controlling for sociodemographic, pathologic, and treatment variables; however, this may be due to patient selection.