Endocrine Abstracts

Background: Although neuroendocrine tumours (NET) constitute a very heterogeneous group, most of them express somatostatin receptors that enable treatment with somatostatin analogues(SA), which proved to be effective both as bio- or radiopeptide therapy. However, little is now about combining this two treatment modalities.The aim of our prospective study was to evaluate results of radiolabeled somatostatin analogues (PRRT) with or without long lasting ‘cold’ SA as consolidation treatment.

Materials and methods: Only patients without carcinoid syndrome were included into the study. All were treated with PRRT (four to five cycles repeated every 6–12 weeks). After the last cycle of PRRT treatment response was evaluated with scintigraphic, radiological and biochemical examination. Thereafter patients were randomly assigned either to treatment with SA or observation group. Initiation of next line of therapy was left to discretion of treating physician.

Patients were followed-up at 4–12 months intervals with radiological examinations (CT or MRI) and receptors scintigraphy. Median time to progression was measured from the start of PRRT treatment till the day of disease progression confirmed in radiological or scintigraphic examination.

Results: patients (79 in SA and 46 in observation group) were included into the study. Twenty-eight patients (57%) from observation group started SA treatment due to development of carcinoid syndrome.

After median follow-up of 34 months, 81 (65%) of patients progressed and 48 (38%) died. Median time to progression was 29 months. There was no difference between patients in SA and observation group. SA treatment after PRRT was well tolerated and no G3-4 side effects were observed.

Conclusions: Preliminary results suggest that consolidation treatment with SA did not improve results of PRRT. However, larger number of patients and longer follow-up is necessary.