Typical and atypical carcinoid tumours: analysis of the experience of the Spanish Multi-centric Study of Neuroendocrine Tumours of the Lung

Abstract
Background: This study examines the experience of the Spanish Multi-centric Study of Neuroendocrine Tumours of the Lung with patients treated surgically for typical and atypical carcinoid tumours. Methods: From 1980 to 2002, 661 patients were treated surgically for 569 typical carcinoid tumours and 92 atypical carcinoid tumours. Three hundred and four cases were studied retrospectively from 1980 to 1997 (261 typical carcinoid and 43 atypical carcinoid tumours); the other 357 new cases (308 typical carcinoid and 49 atypical carcinoid tumours) were collected prospectively from 1998 to 2002. Tumours were classified according the 1999 classification from the WHO and the International Association for the Study of Lung Cancer (IASLC). Several variables were reviewed in all patients. Univariate and multivariate statistical analyses were performed in order to determine whether clinical characteristics were associated with significant differences in survival. Results: In the total of the patients, 5-year survival for different tumours was as follows: typical carcinoid: overall survival 97%; with nodal involvement 100%; atypical carcinoid: overall 78%; with nodal involvement 60%. A significant difference in survival was found between patients in the retrospective and prospective groups with atypical carcinoid and nodal involvement. The comparative analysis of several factors in typical and atypical carcinoid tumours showed a significant difference for mean age, tumour size, nodal involvement and distant metastases. Conclusion: Nodal involvement and histological sub-type appear as the most important factors influencing the prognosis. Adequate lung resection and systematic radical mediastinal lymphadenectomy should always be performed. Sleeve resection could be performed in central typical and atypical carcinoid tumours, avoiding pneumonectomy.