Oxaliplatin and 5-fluorouracil (FOLFOX) in advanced well-differentiated digestive neuroendocrine tumors: A multicenter national retrospective study from the French Group of Endocrine Tumors (GTE).

Abstract

4104 Background: Oxaliplatin-based regimens have shown promising antitumor activity in digestive neuroendocrine tumors (NETs), however the available data are limited. Our aim was to assess the tumor response and survival in a large series of patients treated with oxaliplatin and 5-fluorouracil (FOLFOX) for advanced digestive NETs.Oxaliplatin-based regimens have shown promising antitumor activity in digestive neuroendocrine tumors (NETs), however the available data are limited. Our aim was to assess the tumor response and survival in a large series of patients treated with oxaliplatin and 5-fluorouracil (FOLFOX) for advanced digestive NETs. Methods: All patients with advanced well-differentiated digestive NETs treated with at least 3 cycles of FOLFOX between 2004 and 2018 in 12 centers of the French GTE, were retrospectively included. Best response according to the RECIST 1.1 criteria, progression-free survival (PFS) and overall survival (OS) were evaluated. The prognostic factors for PFS were investigated by multivariate analysis using a Cox proportional hazard model including variables with a p value ⩽ 0.20 in univariate analysis. Results: One hundred and forty-nine patients were included. Primary tumor location was pancreas (n = 88), small intestine (n = 37), stomach (n = 7), rectum (n = 4) and unknown without lung tumor at CT scan (n = 13). Partial response rate was of 31% for pancreatic NETs, 13% for small intestine NETs, 14% for gastric NETs, 25% for rectal NETs and 38% for unknown primary NETs. Median PFS were, respectively, 9, 9, 14, 4 and 6 months, and median OS were 30, 28, 31, 25 and 15 months. Significant poor prognostic factors for PFS after FOLFOX in digestive NETs were: progressive disease (HR = 2.5, p = 0.018), hepatic involvement > 50% (HR = 1.8, p = 0.009), prior targeted therapy (HR = 1.5, p = 0.048) and rectal primary tumor (HR = 4.2, p = 0.01). Among pancreatic NETs, the 9 insulinomas had a 22 months PFS versus 9 months for the others (p = 0.025), and serum glucose normalization was obtained in 8 out of 9 cases. Conclusions: FOLFOX has a promising clinical activity for gastroenteropancreatic NETs, especially in insulinomas.