Molecular pathology and genetics of gastrointestinal neuroendocrine tumours

Abstract

Purpose of review: Neuroendocrine tumours (NETs) of the luminal gastrointestinal tract and pancreas are increasing in incidence and prevalence. Prior assumptions about the benign nature of 'carcinoids' and the clinical importance of distinguishing functional vs. nonfunctional tumours are being overturned through greater understanding of disease behaviour and heterogeneity. This review highlights the most contemporary genetic and molecular insights into gastroenteropancreatic NETs.

Recent findings: Biomarkers such as neuron-specific enolase or chromogranin A could be supplemented or supplanted by PCR-based analysis of NET genes detectable in the blood transcriptome. Conventional pathology, including Ki67 testing, could be enhanced with immunohistochemistry and exome analysis. Prognostic markers and/or putative therapeutic targets uncovered through recent studies include heparanase, Id, ATM, SRC, EGFR, hsp90 and PDGFR.

Summary: After a long-standing paucity of options for conventional cytotoxic therapy, the comprehension and treatment of gastroenteropancreatic NETs has been enriched by advancements in taxonomy, molecular pathology and genetic/epigenetic testing.