A National Study of Nodal Upstaging After Thoracoscopic Versus Open Lobectomy for Clinical Stage I Lung Cancer

Abstract

Nodal upstaging after surgical intervention for non-small cell lung cancer (NSCLC) occurs when unsuspected lymph node metastases are found during the final evaluation of surgical specimens. Recent data from The Society of Thoracic Surgery (STS) database demonstrated significantly lower nodal upstaging after thoracoscopic (VATS) lobectomy than after thoracotomy. STS data, however, may be biased from voluntary reporting, and survival was not investigated. We used a complete national registry to compare nodal upstaging and survival after lobectomy by VATS or thoracotomy. The Danish Lung Cancer Registry was used to identify patients who underwent lobectomy for clinical stage I NSCLC from 2007 to 2011. Patient demographics, comorbidity, preoperative staging, surgical approach, number of lymph nodes harvested, final pathology, and survival were evaluated. Nodal upstaging was identified by comparing cT N M with pT N M. Lobectomy for clinical stage I NSCLC was performed in 1,513 patients: 717 (47%) by VATS and 796 (53%) by thoracotomy. Nodal upstaging occurred in 281 patients (18.6%) and was significantly higher after thoracotomy for N1 upstaging (13.1% vs 8.1%; p<0.001) and N2 upstaging (11.5% vs 3.8%; p<0.001). Overall unadjusted survival was significantly higher after VATS, but after adjusting for differences in sex, age, comorbidity, and pT N M by Cox regression analysis, we found no difference between VATS and thoracotomy (hazard ratio, 0.98; 95% confidence interval, 0.80 to 1.22, p=0.88). National data confirm that nodal upstaging was lower after VATS than after open lobectomy for clinical stage I NSCLC. Multivariate survival analysis, however, showed no difference in survival, indicating that differences in nodal upstaging result from patient selection for reasons not captured in our registry.