Sublobar Resection Versus Lobectomy for Early-Stage Pulmonary Carcinoid Tumors ≤3 cm in Size

Objective: This study aimed to determine the optimal surgical procedure for early-stage pulmonary carcinoids (PCs). Background: PCs, comprising typical carcinoids (TCs) and atypical carcinoids (ACs), are rare low-grade malignant tumors. We determine the optimal surgical management for early-stage PCs using data from the Surveillance, Epidemiology, and End Results registry. Methods: Clinical and survival data of patients with early-stage PC tumors with a diameter ≤3 cm were retrieved. The Kaplan-Meier method and logrank tests were used to assess the differences in overall survival (OS). Subgroup analyses were also performed. To reduce the inherent bias of retrospective studies, two propensity score matching (PSM) analysis with (PSM2) or without (PSM1) consideration of lymph node assessment were performed. Results: In total, 2934 patients with PCs, including 2741 (93.42%) with TCs and 193 (6.58%) with ACs, were recruited. After PSM1 analysis, TC patients in the lobectomy group had a significantly better OS than those in the sublobar resection group ( P = 0.0067), which is more remarkable for patients with a tumor diameter of 2 cm <T ≤ 3 cm ( P = 0.0345) and those aged <70 years ( P = 0.0032). However, survival benefits were not found after PSM2 analysis which balanced lymph node assessment. In multivariate cox analysis, age <70 years, female, TC histology and adequate lymph node assessment were associated with better OS. Conclusions: Sublobar resection may not significantly compromise the longterm oncological outcomes in early-stage PCs ≤3 cm in size if lymph node assessment is performed adequately. Further validation in large randomized clinical trials is warranted.