Treatment of malignant midgut carcinoid tumours with a long-acting somatostatin analogue octreotide.

Treatment with the somatostatin analogue octreotide, SMS 201-995 (Sandostatin), has been carried out in a series of 23 patients with malignant midgut carcinoid tumours. The patients received initially 50 micrograms twice a day for six months, thereafter a median of 100 micrograms twice daily. Six of 22 evaluable patients (28%) showed objective tumour response lasting for 6 to 30 months. Stable disease was observed in 8 of the 22 patients (36%) and progressive disease in a further 8 patients (36%). A subjective response with decrease of diarrhoea or flushing was noted in 11 out of 22 patients (50%). Two out of 6 patients with objective response demonstrated a significant decrease of tumour size lasting for 6 and 30 months respectively. In order to maintain the clinical response, the dose had to be increased in all 6 responders. The adverse effects included development of diabetic blood glucose levels in 8 out of 22 patients (36%). Albumin-modified serum calcium levels were significantly reduced after treatment with octreotide 50 micrograms twice a day. One patient developed symptoms of hypocalcemia which was reversed by supplementation with calcium and D-vitamins. The somatostatin analogue SMS 201-995 has a beneficial effect in the treatment of patients with the carcinoid syndrome. However, the precise role of the drug in the long-term management of these patients has to be further investigated.