Carmona-Bayonas A, Jiménez-Fonseca P, Lamarca A, et al. - Using data from the Spanish Group of Neuroendocrine and Endocrine Tumors Registry (R-GETNE), researchers sought to construct and validate a progression-free survival (PFS) prediction model in somatostatin analog (SSA)-treated patients with well-differentiated, gastroenteropancreatic (GEP) neuroendocrine tumors. Represented as a nomogram and an online calculator, an accelerated failure time model was developed as well as external validation was sought in an independent series of consecutive eligible patients (The Christie NHS Foundation Trust, Manchester, United Kingdom). A total of 535 patients (R-GETNE, n = 438; Manchester, n = 97) were recruited. Primary tumor location, Ki-67 percentage, neutrophil-to-lymphocyte ratio, alkaline phosphatase, extent of liver involvement, presence of bone and peritoneal metastases, reported progression status, and the presence of symptoms when starting SSA were identified as 9 covariates that were significantly related to PFS. The stratification, based on estimated PFS, of patients with GEP neuroendocrine tumors taking SSA treatment, was enabled by the GETNE-TRASGU (Treated With Analog of Somatostatin in Gastroenteropancreatic and Unknown Primary NETs) evidence-based prognostic tool. Also, the possible utility of this nomogram was suggested for the stratification of patients with neuroendocrine tumors in forthcoming trials. In daily clinical practice, it could serve as a valuable tool for making treatment decisions.