Endocrine Abstracts

Long-acting somatostatin analogs (SSAs) have long been used for symptom control in patients with functional neuroendocrine tumors (NETs) whereas two recent prospective studies (PROMID and CLARINET) have demonstrated their efficacy in controlling tumor growth in patients with gastrointestinal NETs of different tissue origin. For both purposes currently available agents (octreotide LAR 10–30 mg i.m and lanreotide autogel 60–120 mg s.c.) have been used. In case of refractory syndromes dose escalation or shortening the injection interval form 4 to 3 or 2 weeks has been used. There is agreement that dose escalation is justified in patients with refractory carcinoid syndrome for symptom improvement and potentially the prevention of carcinoid heart disease. Long-acting SSAs have also been used in a non-prospective manner at above the upper labeled dosages for obtaining tumor growth control. The efficacy of high dose octreotide-LAR has been reported in 10 studies. Doses studied ranged from a minimum of either 40 mg per month or 30 mg per 3 wk up to a maximum of 120 mg per month and included over 260 patients. Eight studies suggested that increased doses (median 60 mg/day) could be effective at preventing tumor growth without evidence of increased toxicity. A prospective study is currently evaluating whether Lanreotide Autogel 120 mg given twice monthly may exert further tumor control in patients with established progression on 120 mg/monthly. Appendiceal carcinoids are considered to be amongst the most indolent carcinoid tumors with only a minority developing metastatic disease. As the majority of patients are identified incidentally when undergoing an appendicectomy a number of potentially adverse histopathological findings have been employed to identify patients that may require a hemicolectomy to eradicate any residual disease. Although there is relatively lack of good quality data, tumor size and grade seem to be the ones with the highest predictive value.