Predictors of survival outcomes in patients with neuroendocrine neoplasms: a real-world retrospective study

Neuroendocrine neoplasms (NENs) are rare tumors with increasing incidence. Data on the prognosis of NEN patients in the real-world setting are limited. We aim to explore survival predictors and the impact of novel treatments in a cohort of patients with NENs from various primary sites. This was a retrospective study of subjects diagnosed with gastroenteropancreatic (GEP) or thoracic NENs and referred to a single institution over more than a decade (2010-2023). The primary objective was to describe the overall survival (OS) and progression-free survival (PFS) of patients with advanced-stage disease undergoing first, second, and third-line therapy. The secondary objectives were to identify predictors of OS and PFS. We included 239 NEN patients. Systemic antineoplastic therapies were administered to 149 subjects (62.3%). In patients treated only with first-line therapy, the OS rate was 75 and 74% at 12 and 18 months, respectively. We observed significant univariable associations between Ki-67 index, primary tumor site, morphology, clinical stage, and OS. The multivariable analysis confirmed a significant association between Ki-67 index, clinical stage, and OS. In patients undergoing second-line therapy, the OS rate was 72 and 61% at 12 and 18 months, respectively, and the Ki-67 index was again associated with OS in the multivariable analysis. GEP NEN patients who received 177Lu-Dotatate showed a numerically higher OS rate at 24 months compared to those who did not receive radioligand therapy. In this real-world study of patients with NENs, we confirmed Ki-67 as a strong prognostic parameter and suggested that 177Lu-Dotatate has the potential to prolong OS.