Comparison the efficacy and safety of different neoadjuvant regimens for resectable and borderline resectable pancreatic cancer: a systematic review and network meta-analysis

Background To date, the optimal recommended specific neoadjuvant regimens for resectable or borderline resectable pancreatic cancer (RPC or BRPC) remain an unanswered issue. Methods We systematically searched the electronic databases to identify randomized controlled trials (RCTs) comparing different neoadjuvant therapy strategies for RPC or BRPC. The primary outcome was overall survival (OS). Comprehensive analyses and evaluations were performed using the single-arm, paired, and network meta-analyses. Results Twelve RCTs involving 1279 patients with RPC or BRPC were enrolled. The paired meta-analysis showed that neoadjuvant therapy improved OS for both RPC (hazard ratio (HR) 0.69, 95% c.i. 0.54 to 0.87) and BRPC (HR 0.60, 0.42 to 0.86) compared with upfront surgery (UP-S). Neoadjuvant chemotherapy (NAC) also improved OS for both RPC (HR 0.63, 0.47 to 0.85) and BRPC (HR 0.44, 0.27 to 0.71), while neoadjuvant chemoradiotherapy (NACR) improved OS only for BRPC (HR 0.68, 0.52 to 0.89) and not for RPC (HR 0.79, 0.54 to 1.16). Network meta-analysis found that NAC was superior to NACR in OS for RPC/BRPC (HR 0.58, 0.37 to 0.90). Neoadjuvant chemotherapy based on modified fluorouracil/folinic acid/irinotecan/oxaliplatin (NAC-mFFX) and neoadjuvant chemotherapy based on abraxane/gemcitabine (NAC-AG) ranked first and second in OS for RPC/BRPC. Conclusions Both RPC and BRPC could obtain OS benefits from neoadjuvant therapy compared with UP-S, and NAC improved OS both in RPC and BRPC while NACR only improved OS in BRPC. Furthermore, NAC was superior to NACR, and NAC-mFFX and NAC-AG might be recommended sequentially as the best neoadjuvant therapy strategies.