Extent of Resection and Lymph Node Assessment for Clinical Stage T1aN0M0 Typical Carcinoid Tumors

Abstract

The optimal extent of lung resection and lymph node (LN) assessment for surgical treatment of clinical stage T1aN0M0 typical carcinoid tumors is unclear. Using a cohort including only these patients, we aimed to determine the impact of extent of lung resection and LN assessment on overall survival. Patients undergoing lobectomy or sublobar resection for clinical stage T1aN0M0 intraparenchymal typical carcinoid tumor were identified in the National Cancer Data Base from 1998 to 2012. Kaplan-Meier analysis was used to determine overall survival. A multivariable Cox proportional hazards model was used to determine independent predictors of mortality. Of 1,495 patients, 536 (35.9%) had sublobar resection (wedge resection, n= 429; segmentectomy, n= 91) and 959 (64.2%) had lobectomy. There were 366 patients (24.5%) with no LN assessment. As tumor size increased, sublobar resection decreased and LN assessment increased. Overall, 60 patients (4.0%) were upstaged. Fifty-two patients were upstaged because of LN metastases (40 pN1, 11 pN2, and 1 pN3). The 5-year overall survival rate was 87%. It was 88% for lobectomy versus 87% for sublobar resection (p= 0.3), 65% for LN upstaging versus 89% for patients without LN upstaging, and 86% for patients with no LN assessment (p= 0.002). Independent predictors of mortality included LN upstaging, age, male sex, and Charlson comorbidity index. For patients with clinical stage T1aN0M0 typical carcinoid, sublobar resection results in similar overall survival compared with lobectomy. However, regardless of resection type, LN assessment is important to identify LN upstaging, the strongest independent predictor of overall mortality.