Abstract 568P
Background
Well-differentiated neuroendocrine tumors (NETs) are relatively rare, highly vascularized neoplasms. Antiangiogenic drugs have shown efficacy in patients with advanced NETs, although the efficacy of FOLFOX-bevacizumab has been scarcely described in this setting. Hence, we aimed to report its efficacy and tolerance in patients with metastatic NETs.
Methods
We retrospectively studied the records of all consecutive patients with metastatic well-differentiated digestive or lung NETs, treated by FOLFOX-bevacizumab, in two expert centers, from 2013 to 2020. We analyzed time to treatment failure (TTF), objective response (OR) rate and toxicity. We assessed factors associated with TTF and OR using multivariate Cox proportional hazard or logistic regression models, respectively.
Results
We included 57 patients (65% male, median age 62 years), with mostly pancreatic (67%), small-intestine (14%) or lung (7%) NETs. Most patients (58%) had extra-hepatic metastases, including bone metastases in 35% of cases, and median Ki-67 index was 18% (G3 NETs, 40%). Patients had either progressive disease (82%) or were treated on first line (18%). Patients received a median of 17 cycles of FOLFOX-bevacizumab (interquartile range, 9-31), including a median 10 cycles of bevacizumab and/or LV5FU2 maintenance. The median TTF was 15.5 months (95% CI [9.8-21.2]). At multivariate analysis, age >60 years (HR 2.09, 95% CI (1.01-4.33), p=0.048) and >1 previous systemic treatment line (HR 3.55, 95% CI (1.60-7.09), p=0.002) increased the risk of treatment failure. The OR and disease control rates were 43% and 95%, respectively. The OR rate was 53% among pancreatic NETs and was higher in G3 NETs (57%) compared to G2 NETs (33%) and G1 NETs (0%). Performance status at 0 (OR 5.85, 95% CI (1.29-26.53), p=0.022) and G3 NET (OR 5.47, 95% CI (1.26-23.65), p=0.023) independently increased the probability of OR.
Conclusions
The FOLFOX-bevacizumab combination has promising efficacy in patients with progressive metastatic NETs, notably in those with G3 NETs, for which optimal treatment is ill-defined yet. Hence, it could be a relevant alternative to alkylating-based chemotherapy in this setting and should be further explored prospectively.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
APHP.
Funding
Has not received any funding.
Disclosure
All authors have declared no conflicts of interest.