Clinicopathological Features of Gastroesophageal Neuroendocrine Neoplasms

Gastroesophageal neuroendocrine neoplasms (NENs) are a rare entity. Recent 2019 WHO classifications reflect our understanding of tumor biology, namely, that distinct molecular characteristics underline tumor behavior and prognosis. Here, we reviewed the evidence for linking molecular findings with the clinicopathological features and treatment of gastroesophageal NENs.

Degree of differentiation and Ki-67 proliferation index are required for accurate classification of neuroendocrine tumors and carcinomas but not sufficient to distinguish between the two entities. Resection remains the mainstay treatment for early-stage gastroesophageal neuroendocrine tumors. Additional perioperative therapy may benefit mitotically active tumors. There is a role for somatostatin analogues, especially in the setting of metastatic and symptomatic disease. New radiolabeled somatostatin analogues, immunotherapy, and embolization offer multimodality treatments for distant metastases. We need to understand the specific underlying biology of the various subtypes of gastroesophageal NENs to provide tailored treatment.