Improved Lymph Node Staging in Early-Stage Lung Cancer in the National Cancer Database

Abstract

Background: Lymph node assessment for non-small cell lung cancer (NSCLC) shows wide variation among centers. Our aim was to assess the quality of lymph node assessment in early-stage NSCLC and determine whether any factors are associated with improved lymph node harvest.

Methods: We queried the National Cancer Database to identify patients with clinical stage I NSCLC who underwent segmentectomy or lobectomy between 2004 and 2013. Patients were stratified into three groups (≤5, 6 to 15, and >15) based on the number of lymph nodes assessed.

Results: Patients (n = 51,358) met criteria, and mean lymph nodes assessed increased from 8.1 to 10.0 (p < 0.001) over the study period. There was a significant decrease in the percentage of patients with 0 to 5 nodes assessed (41.1% versus 31.1%, p < 0.001) and a significant increase in patients with more than 15 nodes assessed (10.1% versus 17.0%, p < 0.001). Patients at academic centers were less likely to have only 0 to 5 nodes assessed (27.2% versus 43.6% for community, p < 0.001). Variables associated with more than 15 nodes assessed were increasing year, age older than 65 years, male sex, non-African American race, academic centers, lobectomy, and clinical T2 disease. Patients with more than 14 nodes assessed demonstrated more nodal upstaging (17.9% versus 10.9% for 1 to 14 nodes, p < 0.001). Multivariable analysis suggests that at least 14 nodes should be assessed to maximize the probability that node-positive patients are correctly identified.

Conclusions: Lymph node assessment has improved since 2004 but varies by facility type and other characteristics. In our analysis removing at least 14 nodes was associated with more accurate staging.