Role of Biomarkers in Diagnosis and Management of NETS

The discussion centered on the evolving and often confusing role of biomarkers in neuroendocrine tumors (NETs)—described by Dr. Shaheen as the “wild west” of oncology. Experts agreed that histologic biomarkers remain foundational, distinguishing well- from poorly differentiated tumors through morphology and molecular markers such as chromogranin, synaptophysin, ATRX, DAXX, TP53, and RB. Ki-67 continues to be essential for grading and prognostication, while somatostatin receptor (SSTR) expression serves as both a diagnostic and predictive biomarker guiding the use of somatostatin analogs and radioland therapy. Next-generation sequencing (NGS) is mainly reserved for neuroendocrine carcinomas and select higher-grade NETs, performed upfront in grade 3 or when tumor behavior suggests progression or atypia; rarely is it used routinely in grade 1/2 NETs, except for specific cases like thoracic or thymic neoplasms. Chromogranin, though widely ordered in the past, is now discouraged for routine use due to poor specificity; imaging and advanced molecular markers are preferred for monitoring and management decisions.