BACKGROUND: Long acting somatostatin analogues combined with platinum analogues have demonstrated an antiproliferative effect on growth of human SCLC xenographs.METHOD: 130 previously untreated SCLC patients--54 with limited disease (LD) and positive somatostatin receptors were included in the study. All patients performed 111In-Octreotide scanning before chemotherapy (CHT), every 3 months and up to 4 times. All patients were treated with paclitaxel 190 mg/m2+carboplatin AUC=5.5 for up to 6 cycles. 47/130 patients (Group A, control group) received only CHT. Forty eight hours after each CHT 43/130 patients (Group B) were also administered 30 mg somatuline® (lanreotide) by a single subcutaneous (s.c.) injection to stimulate somatostatin receptors (SSTRS) for 2 weeks. 40/130 patients (Group C) received 60 mg somatuline® autogel to stimulate SSTRS for 4 weeks. Patients in Groups A and B after the completion of the CHT continued maintenance therapy with somatuline. NSE, IGF1, VEGFA, VEGFC, VEGFR2, HER2 levels were monitored. In histological samples Bcl-2 and VEGF were also explored by immunohistochemistry.RESULTS: No statistically significant differences were observed between the 3 Groups regarding LD and extensive disease (ED) patient ratios, age and PS. Group B had a survival benefit in comparison to Groups A and C (p=0.029). LD patients of Group B had a significant benefit compared to Groups A and C (p=0.012, Breslow test). In LD Group B had a significant longer TTP (p=0.02) in comparison to Groups A and C. Adverse effects had no statistically significant difference between the Groups and toxicity was well managed.INTERPRETATION: Long acting somatostatin analogues could be used as an additive therapy in combination to antineoplastic agents in patients positive for somatostatin receptors. A dose of 30 mg improved survival only in LD SCLC patients.