Impact of lymph node evaluation standard in patients undergoing lung resection for clinical stage IA pulmonary adenocarcinoma and squamous cell carcinoma

Background: The American College of Surgeons Commission on Cancer (CoC) revised operative quality standards recommending resection of lymph nodes from at least one hilar station and three different mediastinal stations in all curative-intent pulmonary resections. This study evaluated the prognostic value and factors associated with adherence to this new CoC standard in patients with resected clinical stage IA non-small cell lung cancer (NSCLC). Methods: Retrospective review of 654 patients who underwent pulmonary resection for clinical IA NSCLC. The study population was divided into patients that met and did not meet the CoC standard. Results: The CoC standard was met in only 254 (38.8%) patients. Factors associated with meeting the CoC standard included left-sided resections, open technique, and type of pulmonary resection. CoC standard was met in 51.6% of lobectomies, 29.9% of segmentectomies, and 17.1% of wedge resections (P<0.001). Nodal upstaging was more frequent in patients meeting the CoC standard (21.3% vs. 12.5% when standard not met; P=0.004). Time to recurrence [adjusted hazard ratio (aHR): 0.86, 95% confidence interval (CI): 0.63-1.17, P=0.33] and overall survival (aHR: 0.78, 95% CI: 0.58-1.05, P=0.10) were not different between CoC standard groups. However, patients not meeting the CoC standard and classified as pN0 exhibited an overall survival that resembled that of patients with pN1 disease. Conclusions: Left-sided resections, open technique and lobectomy were associated with meeting the CoC standard. However, this standard did not have a significant impact on long-term outcomes. Larger studies with longer follow-up are needed to clarify the role of the CoC standard in patients with resected stage IA NSCLC.