Assessment of outcomes in typical and atypical carcinoids according to latest WHO classification

Pulmonary carcinoid tumors represent a group of malignant neoplasms comprised of neuroendocrine cells. In 1999, the World Health Organization (W.H.O.) proposed the definitive classification of neuroendocrine tumors based on the criteria from Travis and associates. The W.H.O. described two different groups of carcinoid tumors: typical carcinoids (TC) and atypical carcinoids (AC). Few reports have reviewed their data according to the current classification, and therefore, prognosis and standard therapy for TC and AC are still uncertain.

From 1980 to 2001, 98 pulmonary resections have been performed for primary bronchial carcinoid tumors in our Thoracic Department of the University of Milan. We reviewed original histology using the current W.H.O. criteria and identified 88 patients with TC and 10 with AC. We reviewed the outcomes in each group.

The 5 year-overall survival rate was 91.9% for TC and 71% for AC. The 10-year overall survival rate was 89.7% for TC and 60% for AC. The 5-year TNM-related survival rates in the TC group were: IA-B, 100%; IIA-B, 75%; and IIIA, 50%. At 10 years, they were: IA-B, 100%; IIA-B, 75%; and IIIA, 0%. The 5-year survival rates in the AC group were: IA-B, 100%; IIA-B, 100%; and IIIA, 0%. At 10 years, they were: IA-B, 100%; IIA-B, 66%; and IIIA, 0%.

Prognosis is favorable for both subtypes in the early stage. Advanced stages are related to better prognosis in TC. Recurrences rate is worse in the AC subtype. Our data suggest avoiding limited resections when feasible in AC. Parenchyma-sparing resections should be encouraged in TC.