Risk Factors for Disease Progression in Advanced Jejunoileal Neuroendocrine Tumors.

Background: Knowledge of clinical course in advanced jejunoileal neuroendocrine tumors (NETs) is poor. Aim: To investigate progression-free survival (PFS), overall survival (OS), and possible predictors for disease progression (DP) in advanced jejunoileal NETs. Patients and Methods: We carried out a multicenter, retrospective analysis of incoming patients with sporadic advanced jejunoileal NETs. PFS and OS were assessed by Kaplan-Meier analysis. Risk factors for progression were analyzed by the Cox proportional hazards method. Results: Of the 114 patients enrolled, 46.5\% had functioning tumors, 93.9\% had stage IV disease, and 57.3 and 42.7\% were G1 and G2 tumors, respectively. During a median follow-up of 48 months (interquartile range 29-84 months), DP occurred in 61.4\% of patients, after 19 months (interquartile range 10-41 months) from diagnosis. Median PFS was 36 months. The 2-year and 5-year PFS were 59 and 33\%, respectively, while 5-year OS was 77.5\%. Ki67 was the sole strong independent risk factor for unfavorable outcome according to multivariate analysis, being significantly associated with both PFS and OS. Conclusions: DP occurred in the majority of patients with advanced jejunoileal NETs, with median PFS being 36 months. Ki67 was a significant predictor of DP and should be considered in determining appropriate treatments and planning follow-up for these patients.