Single dose of octreotide stabilize metastatic gastro-entero-pancreatic endocrine tumours

Background and aim. Somatostatin analogues are able to control symptoms and to detect tumour localisation in gastro-entero-pancreatic endocrine tumour patients. Few studies have evaluated the efficacy of somatostatin analogues in controlling tumoural growth during long-term treatment and, generally, a low efficacy has been reported in studies using multiple daily octreotide dosages. In the present study a single daily dose of octreotide (500 μg) for 1 year was used in the treatment of 10 patients with progressive gastro-entero-pancreatic metastatic tumour. Patients. Ten consecutive patients (3 females, 7 males age range 40-62 years) were studied of whom 4 had Zollinger-Ellison syndrome (2 with MEN-1), 3 had a carcinoid syndrome, and 3 had a non-functional neuro-endocrine tumour. All patients, 6-12 months before octreotide treatment, showed tumour progression. In all patients, somatostatin receptor status was assessed by Somatostatin Receptor Scintigraphy and tumour lesions by Magnetic Resonance Imaging. Appropriate tumoural markers were also evaluated. Results. At the three-month control, two patients (non-functional) showed an aggressive progression of tumoural growth despite treatment and were excluded from the study. One patient was lost during follow-up. Of the 7 remaining patients, imaging evaluation studies revealed, after 1 year of treatment, stable disease in 6 patients, whereas a partial tumoural response was observed in one patient (gastrinoma). Biochemical tumoural markers decreased with respect to basal values of 53-78% in these seven patients at the end of therapy. Conclusions. These results suggest that one year of octreotide in a single daily dose (500 μg) is effective in the long-term stabilization of tumoural progression in metastatic gastro-entero-pancreatic tumour patients.