Folfirinox versus gemcitabine/nab-paclitaxel for neoadjuvant treatment of resectable and borderline resectable pancreatic adenocarcinoma: A propensity matched analysis.

Abstract

402 Background: Comparative effectiveness of FOLFIRINOX and Gemcitabine/nab-paclitaxel (G-nP) in the neoadjuvant treatment (NAT) of pancreatic ductal adenocarcinoma (PDA), remains unknown. The aim of this study was to perform a propensity matched analysis of neoadjuvant FOLFRINOX vs G-nP for resectable(R) and borderline resectable (BR) PDA. Methods: A single institution retrospective review of all R and BR PDA patients who underwent resection after NAT with FOLFIRINOX or G-nP was performed. Comparative effectiveness analysis was conducted using inverse-probability-weighted estimators. Primary endpoint was overall survival (OS) from the time of diagnosis. Results: A total of 193 patients (FOLFIRINOX=73, G-nP=120) who underwent resection from 01/11-03/17 were included. Median OS was 28.9 months (95% CI 26.1-39.7). Patients treated with FOLFIRINOX were younger (median age 63 vs. 69 y), had less comorbidities (median CCI 4 vs. 5), more frequent BR disease (79 vs. 59%), and larger tumors (median CT size 2.9 v 2.7 cm) compared to G-nP (all p < 0.05). Duration of NAT was similar and both regimens were equally effective in achieving a 50% or 80% decline in CA19-9 (logistic regression, P 0.9). Rates of R0 resection were also similar (80%), but folfirnox was associated with a reduction in pN1 disease (56% vs. 72%, p =0.028). Receipt of adjuvant therapy was similar in both groups (74 vs. 75%, p =0.79). In a multivariable cox regression analysis utilizing only preoperative variables (FOLFIRINOX v G-nP, age, gender, CT tumor size, BR vs. R, pre NAT CA19-9 and number of NAT cycles), only the number of neoadjuvant cycles was an independent predictor of survival (HR 0.49, 95% CI 0.34-0.71, p < 0.001). In a propensity matched analysis of 166 patients using the same preoperative variables, the average treatment effect of FOLFIRINOX was to increase OS by 4.9 months above G-nP (p=0.012). Conclusions: FOLFIRINOX and Gem Abraxane are viable options for neoadjuvant treatment of PDA. In this study, FOLFIRINOX was associated with a 4.9 month improvement in OS when compared to G-nP in the neoadjuvant setting after adjusting for covariates.