Endoscopic Resection for GEP-NET

Abstract

Neuroendocrine tumours (NET) are rare tumours of the gastrointestinal tract. Many of these are diagnosed incidentally during routine upper and lower GI endoscopy. Complete surgical resection is the treatment of choice for localised tumours. For small tumours with no associated risk factors for metastases, endoscopic resection can be performed with curative intent. This endoscopic approach is standard of care for gastric, duodenal and rectal NET. In contrast, NET of the jejunum and ileum should not be treated endoscopically, as they exhibit a high rate of metastases independent of tumour size. The feasibility of an endoscopic resection is defined by the technical possibility of achieving an R0 resection, the complication rate of the procedure and the suspected rate of lymph node metastases. In general, endoscopic resection is recommended for tumours less than 1cm in size, since they can be successfully endoscopically resected without major complications and carry a low risk of metastases. All tumours above 2cm should be surgically resected, as endoscopic R0 resection is unlikely and risk of lymph node metastases is high. Tumours of between 1cm and 2cm could be approached by both surgical or endoscopic resection. A novel approach for these "in between" tumours is a combined endoscopic-laparoscopic rendezvous to achieve limited organ-sparing resection with maximal safety. This approach is particularly useful for duodenal NET as the risk of perforation is high for endoscopic resection.