Systemic chemotherapy of advanced digestive neuroendocrine tumours.

The efficacy of chemotherapy on digestive neuro-endocrine tumours is not yet fully established and depends on the tumour type and on the differentiation of the neuro-endocrine tumours. Reports have indirectly suggested the superior activity of chemotherapy for pancreatic neuro-endocrine tumours than for metastatic carcinoid tumours (response rates around 60% vs 20%). Neuro-endocrine tumour differentiation is also a major factor and a higher chemotherapy efficacy (tumour responses: 69%) has been suggested in undifferentiated or poorly differentiated neuro-endocrine tumours which respond to chemotherapy, a little like small cell lung carcinomas. The efficacy of interferons has also been reported in phase II trials only, with symptomatic and biological responses in about 50% of the cases and tumour responses in 10 to 15%; some studies have suggested an interesting tumour growth control with prolonged survival but this efficacy has still to be investigated to clearly establish the best indications. The role of chemotherapy has to be discussed with surgeons and, in slowly progressing tumours, after the use of somatostatin analogues.