Diagnostic and therapeutic management of neuroendocrine lung tumors: a clinical study of 44 cases.

Neuroendocrine tumors of the lung (NTL) are a distinct subset of tumors with a wide range of histological patterns and clinical behavior. Controversy still exists as to the ideal diagnostic and therapeutic approach to these neoplasms. A series of 44 consecutive NTL patients operated on at our Institution was retrospectively reviewed in order to critically analyze the diagnostic and therapeutic management. A preoperative diagnosis was obtained in 11 patients (25%). All patients underwent an anatomical surgical resection with lymphoadenectomy. Pathological diagnosis was typical carcinoid (TC) tumor in 36 cases, atypical carcinoid (AC) in three and large-cell neuroendocrine carcinoma (LCNEC) in five. One patient had preoperative chemotherapy. Node-positive patients received postoperative radiotherapy on the mediastinal area. Median follow-up time was 40 months for TC and 51.5 months for AC/LCNEC. Recurrence of disease was observed in three patients with TC and in two with AC/LCNEC. Actuarial 5-year survival was 93% for TC and 70% for AC/LCNEC. Survival was not influenced by tumor size, while lymph node metastases were associated with a worse prognosis. However, due to the limited number of patients, no statistical significance was observed. In conclusion, our study confirms findings in the literature showing that TC and AC/LCNEC are clinically different, and that a differential preoperative diagnosis and treatment is necessary. Although the results of new diagnostic techniques such as octreotide scintigraphy are encouraging, they need to be validated in a larger number of patients. Surgery, with anatomical resection and lymphoadenectomy, remains the treatment of choice in all these tumors. Laser treatment should be considered only as a palliative procedure or as a complementary technique to surgery. The role of adjuvant treatments in AC and LCNEC is uncertain and should be evaluated in larger trials. The prognostic role of biological factors such as cytometry and genetic markers requires further investigation before any definitive conclusions can be drawn.