Embolisation therapy in the midgut carcinoid syndrome: just tumour ischaemia?

Forty-eight patients with midgut carcinoid tumours and disseminated disease were treated at our unit 1986-1991. All patients underwent primary surgery with optimal tumour reduction. Twenty-seven patients with bilobar liver metastases had subsequent embolizations of the hepatic arteries to further reduce the functional tumour mass and were thereafter treated with a low dose of octreotide. The response to this treatment was evaluated by CT at 3 months postembolization. The patients could then be divided into 13 responders (no visible hepatic tumours or more than 50% reduction, group I) and 14 non-responders (less than 50 reduction or progression, group II). When these patients were studied biochemically and in terms of prognosis, the reduction of 5-HIAA levels postembolization was much more pronounced in group I (80 +/- 3%) then in group II (28 +/- 12%). The biochemical and radiological responses were long-lasting in group I, none of the patients needed further ischaemic treatment. Of specific interest were 3 patients with bilobar disease, who after selective unilobar embolisation normalised their 5-HIAA levels and had bilateral tumour regression. These findings indicate involvement of systemic effects in addition to tumour ischaemia alone. The initial biochemical response with marked decrease of 5-HIAA levels in combination with tumour regression may thus serve as an indicator of good prognosis.