[Mid gut neuroendocrine tumors: News on medical treatment]

Abstract

Context: Mid gut neuroendocrine tumors (NET) are rare tumors whose incidence is increasing. Curative surgery remains the gold standard for the treatment of NETs of the small intestine. Surgery should be considered as soon as possible even if a metastatic stage is diagnosed. The management of unresectable well-differentiated metastatic NETs of the small intestine recently changed with the publication of trials demonstrating the benefit of targeted therapies and metabolic radiotherapy, leading to a change of practices and update of French and international recommendations.

Objective: The objective of this review is to present the recent data consisting of three phase III studies, which modify the management of well-differentiated metastatic midgut NETs and make an inventory of the available treatment options.

Documentary sources: The documentary sources used were gathered through the PubMed website using keyword searching (neurendocrine tumor, mid gut, treatment). We also referred to recommendations of the European Society of neuroendocrine tumors (ENETS) trials presented at ESMO Congress 2015 (European Society for Medical Oncology).

Study selection: We excluded studies of exclusive extra-digestive NETs, poorly differentiated NETs, surgical treatments and phase I studies.

Results: We discussed three randomized phase III trials: CLARINET, RADIANT and NETTER studies. These studies demonstrated the efficacy of respectively somatostatin analogues, mTOR inhibitors and metabolic radiotherapy.

Conclusion: This review highlights the validation by randomized studies of an mTOR inhibitor and metabolic radiotherapy in metastatic non-pancreatic digestive NETs unresectable well-differentiated grade of G1/2 in progression under somatostatin analogues.