Published online Oct 16, 2021. doi: 10.12998/wjcc.v9.i29.8627
Peer-review started: February 20, 2021
First decision: May 3, 2021
Revised: May 19, 2021
Accepted: August 24, 2021
Article in press: August 24, 2021
Published online: October 16, 2021
Processing time: 236 Days and 21.9 Hours
Neuroendocrine tumors (NETs) are a rare and heterogeneous disease group and constitute 0.5% of all malignancies. The annual incidence of NETs is increasing worldwide. The reason for the increase in the incidence of NETs is the detection of benign lesions, incidental detection due to the highest use of endoscopic and imaging procedures, and higher recognition rates of pathologists. There have been exciting developments regarding NET biology in recent years. Among these, first of all, somatostatin receptors and downstream pathways in neuroendocrine cells have been found to be important regulatory mechanisms for protein synthesis, hormone secretion, and proliferation. Subsequently, activation of the mammalian target of rapamycin pathway was found to be an important mechanism in angiogenesis and tumor survival and cell metabolism. Finally, the importance of proangiogenic factors (platelet-derived growth factor, vascular endothelial growth factor, fibroblastic growth factor, angiopoietin, and semaphorins) in the progression of NET has been determined. Using the combination of biomarkers and imaging methods allows early evaluation of the appropriateness of treatment and response to treatment.
Core Tip: Neuroendocrine tumors (NETs) originate from cells of the diffuse neuroendocrine system that can show both nerve and endocrine cell features and can be found in many organs in the body. NETs show different clinical and biological characteristics according to the regions where they develop. In recent years, there have been changes in the distribution of NETs within themselves, especially due to the more frequent use of screening colonoscopy and imaging methods. Using the combination of biomarkers and imaging methods allows early evaluation of the appropriateness of treatment and response to treatment.