Comparative study expression of somatostatin receptors type 2 by means of RT- PCR and outcome on octreotide therapy in neuroendocrine tumours of the lung

Purpose: We have compared the expression of somatostatin receptors type 2 (SSTR2) with the outcome of 111-InDTPA-Pentetreotide scintigraphy (Octreoscan-OCT) and the effect of octreotide treatment in neuroendocrine Tumors (NET) of the lung Tissue from 7 patients operated for NET were analyzed by meens of RT-PCR Al cases were positive for SSTR2. Methods: There were 2 male and 5 female with mean age 37 years; histologically there were 5 well differentiated NET (so colled typical carcinoids and 2 moderate differentiated NET (so colled atypical carcinoids). Preoperative OCT was positive in an the patients, showing the pulmonary lesion without mediastinal or dissent metastases. These cats were confirmed by traditional radiological procedures, and by histological examinations Three patients (1 male and 2 female; 2 moderate differentiated NET and 1 well differentiated NET) developed carcinoid syndrome due to liver (1 case) and ipsilateral mediastinal metastases (2 cases) 2; 2 and 0.5 years respectively, after operation. OCT was repeated at the time of metastatic spread in al the three patients, and confirmed the recurrent NET by strong uptake in the liver sad ill the mediastinum Medical therapy with octreotide at the dose of 1500 ??g/die subcutaneously was immediately administrated; the patients were not eligible for surgery or chemoResults: The treatment resulted in relief of carcinoid Syndrome in al the cases, accompanied by regression of mediastinal metastases in 1 case and stable disease in the other, as observed in OCT and radiological controls. Conclusions: These findings indicate a positive 111-In-DTPA-Pentetreotide scintigraphy and the response to the treatment with octreotide c on elate to the presence of SSTR2, which bind octreotide with the highest affinity shown by RT-PCR. In addition, the presence of SSTR2 may be useful to select cases available of OCT at the follow-up and possible medical treatment with octreotide.