Neoadjuvant therapy for body and tail pancreatic adenocarcinoma: Propensity score matched analysis using the National Cancer Database.

Abstract

450 Background: The role of neoadjuvant systemic therapy in the management of body and tail pancreatic ductal adenocarcinoma (PDAC) is unknown. The aim of our study was to investigate the outcomes associated with neoadjuvant therapy for early stage body and tail PDAC. Methods: The National Cancer Database (NCDB) was queried for stage I and II body and tail PDAC between 2006-2014. Groups were defined according to treatment sequencing strategies into an upfront resection group (UR), resection followed by adjuvant therapy (R+AT), neoadjuvant therapy followed by resection (NAT+R), and neoadjuvant therapy followed by resection and adjuvant therapy (NAT+R+AT). Patients who underwent neoadjuvant therapy followed by resection were matched by propensity score with patients who underwent upfront resection. Overall survival was compared using Kaplan-Meier method and Cox proportional hazards regression model. Results: 441 patients received NAT+R with or without AT compared to 1323 patient who underwent UR with or without AT. NAT+R had lower pathologic stage, lymph node positivity and a higher rate of margin negative resections compared to the matched UR cohort. In the propensity matched cohort, the median survival (MS) was higher in the neoadjuvant (NAT+R/NAT+R+AT) group compared to the upfront resection (UR/R+AT) group (28.6 vs. 22.9 mo; p<0.001). When further stratified by treatment sequencing the MS was longer in a NAT+R+AT cohort compared to the R+AT group (36.0 vs. 25.3 mo; p<0.05) (Table). However, there was no difference in MS between R+AT and NAT+R cohorts. On multivariable analysis, receipt of NAT represented an independent factor for survival (NAT+R+AT HR 0.41, 95% CI 0.32-0.54; NAT+R HR, 0.53, 95% CI 0.44-0.64; R+AT HR 0.61, 95% CI 0.53-0.70). Conclusions: There appears to be a survival benefit with neoadjuvant systemic therapy in patients with early stage body and tail PDAC. A systemic perioperative treatment sequencing approach (NAT+R+AT) appears to have the greatest survival benefit. [Table: see text]