P-177 - Efficасу of long-acting somatostatin analogues (SA) in patients (pts) with highly differentiated gastroenteropancreatic neuroendocrine tumors (GEP NETs)

Abstract

Introduction: Antiproliferative efficacy of SA in midgut NETs was proved in PROMID study. But this study included patients only with G1 tumors. We assessed efficacy of the SA in pts with metastatic (advanced) G1 and G2 GEP NETs, and also in patients previously treated with chemotherapy. Methods: 60 pts with morphologically proven GEP NETs; among them 18 male (30%) and 42 female (70%), 18 to 82 years old (mean age - 55 years). 28 (47%) pts were previously untreated and 32 (53%) pts had received prior chemotherapy. Primary tumor site: pancreas -19 (32%), intestine -21 (35%), the unknown primary site -20 (33%) cases. Metastases sites: liver -52 (87%), spleen -2 (3%), peritoneum - 13 (22%), lymph nodes - 24 (40%), lungs - 6 (10%), bones - 8 (13%). In all cases with unknown primary site patients had liver metastases. Pathomorphology: G1 - 22 (37%) pts, G2 - 27 (45%) pts and 11 (18%) pts had only cytological verification. Carcinoid syndrome and increased chromogranin A and serotonin serum levels and 5-HIAA urine level were reported in 52 (87%) pts. Regimens: 45 (70%) pts received only SA in the dose of 30 or 40 mg/m2 every 28 days, 13 (30%) pts were given SA in the dose of 30 or 40 mg in combination with interferon α. Results: 51 (85%) pts had stable disease (SD), 9 (15%) pts progressed (PD). Reduction and normalization of CgA, serotonin or 5 - HIAA levels were achieved in 48 (80%) pts. Symptoms control was observed in all cases. Median progression-free survival was 40 months. Median overall survival has not been reached yet. Conclusion: The long-acting somatostatin analogues are effective drugs for the treatment of highly differentiated GEP NETs.