Endocrine Abstracts

Introduction: Neuroendocrine neoplasms (NEN) are heterogeneous tumors, usually sporadic and non-functioning, with a favorable long-term prognosis if localized. Metastases are common and survival outcomes of metastatic patients (pts) is worse than in localized disease.

Aim: To investigate survival outcomes in a monocentric cohort of sporadic NEN.

Materials and Methods: Clinical data of pts with histologically confirmed sporadic NEN, referred to the Endocrinology Unit of Federico II University of Naples from 2012 to 2023, were evaluated retrospectively. The Kaplan-Meier method and log-rank test were used for survival analysis and comparison between groups.

Results: We included 272 pts (137 females/135 males; 50.3%/49.7%) with sporadic NEN, mean age at diagnosis 55.3 years (11-89). Mean follow up was 46.19 months (m) (range 3-276). NEN were identified as incidentalomas in 64 pts (23.5%), due to symptoms in 139 (51.1%) and after surgery in 39 (14.3%); the majority were non-functioning (245; 90%). The most common primary site was pancreas (73, 26.8%), followed by lung (47, 17.3%), and stomach (41, 15.1%); liver was the main metastatic site (80, 29.4%). Grading was G1 in 125 patients (45.9%), G2 in 118 (43.4%) and G3 in 29 (10.7%). Metastatic disease was found in 125 pts (45.9%) and with significant prevalence in male (P<0.03). G1 prevalence was significantly higher in non-metastatic group (M-) (48.3% vs. 27.2%, p: 0.0005); G2-3 prevalences were significantly higher in metastatic group (M+) (respectively 46.4% vs. 32.6%, p: 0.024 and 18.4% vs. 4 %, p: 0.001). Surgery was performed in 134 of 272 pts (50.9%). Mean overall survival (OS) was 46.2 months (m) in M+ and 56.8 m in M-. Kaplan Meier analysis showed a better survival in M- than M+, with no difference between genders (female P=0.001 and male P<0.001). Moreover, a better OS was observed in pts who underwent surgery (P=0.001) and in this subgroup metastases did not show a significant impact on OS (P<0.001).

Conclusions: These data prove that surgery improves OS in metastatic NEN, regardless of the presence of metastases, maybe due to reduced tumor burden. Moreover, metastatic disease is mainly associated with male gender and G2-3 with liver as main metastatic site.