Review article: the investigation and management of gastric neuroendocrine tumours

Abstract

Summary Background Gastric carcinoids (GCs) or neuroendocrine tumours (NETs) are increasingly identified at endoscopy, and account for 0.6–2% of all gastric polyps identified. The SEER database in the US has demonstrated a rising incidence of gastric NETs amongst all NETs; from 2.2% between 1950 and 1969 to 6.0% between 2000 and 2007. Aim To review the literature and assist clinicians in managing patients with GCs. Methods A literature search was conducted through MEDLINE using search terms: gastric, carcinoid, neuroendocrine tumour, therapy, endoscopy, mucosal resection, submucosal dissection. Relevant articles were identified through manual review. The reference lists of these articles were reviewed to include further appropriate articles. Results There are three types of GCs with important epidemiological, pathophysiological, histological and endoscopic differences that affect prognosis and management. Type 1 and 2 GCs develop in the context of hypergastrinaemia that originates from achlorhydria in atrophic gastritis and a gastrinoma, respectively. Type 3 GCs occur sporadically and independent of gastrin. The histological type, grade and Ki67 index are used to determine prognosis and direct clinical management. Type 1 GCs >1 cm in size and type 2 GCs should be assessed for invasion beyond the submucosa with EUS prior to endoscopic resection with EMR or ESD. Type 3 GCs should be managed as per recommendations for gastric adenocarcinoma. The treatment of advanced disease is multimodal. Conclusions Patients with gastric carcinoids should be discussed in a specialist neuroendocrine tumour multidisciplinary meeting to ensure all treatment options are explored in localised and advanced disease. Areas of controversy exist that need further research.

Early diagnosis and treatment of gastrointestinal neuroendocrine tumors

“…Treatment for metastatic NETs includes, surgery, radiotherapy, chemotherapy and palliative care, depending on the individual case (28). If a tumor is limited to the mucosa or submucosa, it may be resected by surgery or by endoscopy using endoscopic mucosal resection or endoscopic submucosal dissection (15,16,(29)(30)(31). Endoscopic resection is not only a curative method, but it also exhibits minimal trauma and a lower cost than other surgical procedures.…”

A single center series highlights on incidence and management of gastric neuroendocrine tumours with literature review

“…The response to medical therapy should be followed clinically and biochemically every 3 months and radiolgically 6 months for 5 years [35]. Gastric neuroendocrine cases, should be discussed individually to tailor the best management in specialised neuroendocrine tumour multidisciplinary meetings [2].…”

Gastric neuroendocrine tumors: management and challenges

“…Overall, tumor invasion beyond the submucosa into the muscularis propria or lymph node and liver involvement occurs in 5-12% of cases. 10 Type II gastric NETs are also associated with hypergastrinemia, but the feature that distinguishes them from type I tumors is their association with ZES and multiple endocrine neoplasia type 1 (MEN1) syndrome, which are hypersecretory states. Up to 30-50% of patients with MEN1 syndrome will develop gastric NETs, especially if ZES is present.…”

“…Up to 30-50% of patients with MEN1 syndrome will develop gastric NETs, especially if ZES is present. 10 Type II gastric NETs unsurprisingly have a high rate of loss of heterogyzosity at the MEN1 gene locus of 75-100%. Interestingly, 17-73% of type I gastric NETs and 25-50% of type III gastric NETs carry the same mutation, suggesting that MEN1 mutations cannot be used to distinguish among the 3 types of gastric NETs.…”