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.