External Validation of a Prognostic Model of Survival for Resected Typical Bronchial Carcinoids

Abstract

This study aimed to assess the reliability and the validity of a prognostic model of survival recently developed by the European Society of Thoracic Surgery Neuroendocrine Tumor Working Group to predict 5-year overall survival after surgical resection of pulmonary typical carcinoid. We retrospectively collected data on 240 consecutive patients (164 men, 76 women; median age, 58 years [interquartile range, 47 to 68]) who underwent curative lung resection for pulmonary typical carcinoid in seven centers between 2000 and 2015. For each patient, we calculated the corresponding risk class (A, B, C, D) using the following variables: male, age, previous malignancy, Eastern Cooperative Oncology Group performance status, peripheral tumor, TNM stage. Kaplan-Meier method, and Cox proportional hazards model were used for the statistical analysis. During a median follow-up of 42 months (interquartile range, 11 to 84), the 5-year overall survival was 94.2% (95% confidence interval [CI]: 90.2% to 98.2%); 15 of 240 patients died. A significantly decreasing rate of survival was observed from class A to class D (p= 0.004) with rates of 100% (95% CI: 100% to 100%), 96.3% (95% CI: 88.6% to 98.8%), 86.7% (95% CI: 63.0% to 95.7%), and 33.3% (95% CI: 0.9% to 77.4%), respectively, for class A, B, C, and D. This difference persisted also using clinical stage as a variable in the risk class calculation (p= 0.006). No differences were observed in term of overall survival among TNM stage I, II, and III patients (p= 0.94). This prognostic model of survival is easily applicable, it is validated by our independent cohort, and it appears to stratify better than the traditional TNM staging. Therefore, it may be useful in counseling patients about their outcomes from surgical treatment and in tailoring treatment for high-risk patients.