Well differentiated grade 3 gastroenteropancreatic neuroendocrine tumors:new insights into diagnosis and therapeutic strategy

Abstract

Gastroenteropancreatic neuroendocrine tumor G3(GEP-NET G3) is a novel subtype of neuroendocrine neoplasms proposed in 2019,which has unique biological behavior characteristics. However,there are still many challenges and controversies in its diagnosis and treatment. There are obvious differences between GEP-NET G3 and neuroendocrine carcinoma (NEC) in genetic alterations and molecular profiles. The most frequently mutated genes in NET G3 are MEN1,DAXX/ATRX,while in NEC,TP53 and Rb are the most frequently mutated genes. Currently,the mainstream view is that NET G3 and NEC are two distinct diseases with different genetic backgrounds,and NET G3 will not develop into NEC. Several clinical and pathological factors should be considered to distinguish GEP-NET G3 and NEC,which including patients' medical history,histopathological morphology of neoplasms,Ki-67 index,immunohistochemical results of TP53,Rb,DAXX/ATRX and other markers. Multidisciplinary treatment,including radical resection,chemotherapy,targeted therapy,peptide receptor radionuclide therapy,immunotherapy should be applied in patients with GEP-NET G3. Overall,given its relatively indolent biological behavior,the therapeutic strategy should be more actively. Although the cure strategy of NET G3 has many similarities with NET G1/2,it is completely different from NEC.