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A carcinoid tumor is a rare malignant disease which can be cured when localized and treated by surgery. Chemotherapy is not effective, and somatostatin is used for palliation. Rarely is the disease aggressive, and thus does not contribute to a shortening of patient survival. The aim of this study was to define the treatment and survival of patients with primary lung carcinoid tumors. Forty-three patients (26 males, 17 females; median age 43 years, range 11-73 years), from 1993 to 2007, were included in this study. All patients had histologically confirmed carcinoid tumors. The site of the disease at diagnosis was the lung in all 43 patients. All patients underwent surgery which involved mainly typical or sleeve lobectomy. Eight patients had a pneumonectomy. One patient had the primary tumor excised for palliation as there were metastases in the liver. Somatostatin palliative treatment was administered to 4 patients; 1 with liver and 3 with lung recurrence. Two of the 43 patients died within 2 years after surgery. The median survival was not reached as all patients, apart from 2, were alive after a median follow-up of 5 years (mean survival 159 months). As a rule, a carcinoid tumor is an extremely slow-growing disease with some rare exceptions. All of our patients had primary lung disease. All, apart from 2, were alive at the end of the study, and 93% were without recurrence for a duration of 6 months to 13 years. The patients with liver metastases who underwent no specific treatment had a median survival as long as 8 years.

The possible causes and genetic mechanisms of pulmonary carcinoid tumor development are unclear. In this study, we examined genetic alterations at the MEN1 locus in archival material from 15 pulmonary carcinoids. We employed, for the first time in this setting, real-time PCR with melting curve analysis in order to identify loss of heterozygosity (LOH) or microsatellite instability (MI) in two polymorphic markers (PYGM, D11S449) at the MEN1 locus and one additional marker (D11S906) of a putative oncosuppressive region distal to the MEN1 gene. Sequencing data were available in a selected subset of tumors in order to verify the reliability of real-time PCR analysis. We observed LOH at PYGM in 38% of the cases and MI in 13.3% of the cases. Our data indicate that real-time PCR with melting curve analysis is a reliable technique for LOH and MI detection and indicate that genetic errors at the MEN1 locus but also distal to it may be involved in the development of sporadic pulmonary carcinoid tumors.