Prognostic factors in ectopic Cushing's syndrome due to neuroendocrine tumors: a multicenter study

OBJECTIVE: Evidence is limited regarding outcome of patients with ectopic Cushing's syndrome (ECS) due to neuroendocrine tumors (NETs).DESIGN: We assessed the prognostic factors affecting the survival of patients with NETs and ECS.METHODS: Retrospective analysis of clinicopathological features, severity of hormonal syndrome, treatments from a large cohort of patients with NETs and ECS collected from 17 Italian centers.RESULTS: Our series included 110 patients, 58.2% female, with mean (±s.d.) age at diagnosis of 49.5 ± 15.9 years. The main sources of ectopic ACTH were bronchial carcinoids (BC) (40.9%), occult tumors (22.7%) and pancreatic (p)NETs (15.5%). Curative surgery was performed in 56.7% (70.2% of BC, 11% of pNETs). Overall survival was significantly higher in BC compared with pNETs and occult tumors (P = 0.033) and in G1-NETs compared with G2 and G3 (P = 0.007). Negative predictive factors for survival were severity of hypercortisolism (P