Evaluation The Impact Of Neoadjuvant Therapy In The Borderline Resectable Pancreatic Cancer With A Meta-analysis

Purpose:Neoadjuvant therapy(NAT)may improved the surviaval and surgical outcomes of borderline resectable pancreatic cancer(BRPC),but no high-level evidence exists.This study compares neoadjuvant therapy with surgery first(SF)in the borderline resectable pancreatic cancer in terms of margin negative(R0)resection rate,overall survival(OS)and other outcomes.Methods:We searched Pubmed,Embase,Web of Science,Corchrane library to identify literatures comparing the surviaval and surgical outcomes of NAT with SF for BRPC.The primary outcomes were OS and R0 resection rate,the secondary outcomes were overall resection rate,pathologic stage,intraoperative blood loss volume,recurrence rate etc.Results:A total of 9 literatures with 855 BRPC patients were enrolled in this meta-analysis,including 1 RCT and 8 cohort studies(2 prospective and 6retrospective).Compared with surgery first,neoadjuvant therapy showed statistically significant advantage of OS in both ITT(intention-to-treat)analysis(HR=0.46,95%CI,0.35-0.61,P<0.001)and analysis of resected patients(HR=0.68,95%CI,0.52-0.89,P=0.004),so did the other primary outcome R0 resectionrate(85.2%vs52.3%,OR=6.19,95%CI,3.96-9.68,P<0.001).NAT reduced the lymph node metastasis(46.9%vs78.4%,OR=0.21,95%CI,0.08-0.55,P=0.001)and tumor diameter(MD=0.55,95%CI,0.36-0.74,P<0.001),but there was no significant difference in the earlier pathologic stage(Ⅰ,Ⅱ)(81.6%vs83.1%,OR=1.08,95%CI,0.53-2.18,P=0.83),the rate of overall resection(84.5%vs82.6%,OR=0.84,95%CI,0.55-1.28,P=0.41)and adjuvant therapy completion(59.2%vs46.5%,OR=1.28,95%CI,0.87-1.87,P=0.21)was not decreased by the NAT.In terms of surgical safety outcomes,NAT can not reduced intraoperative blood loss volume significantly(MD=-47.1,95%CI,-408.33-314.13,P=0.80),so as operate time(MD=17.03,95%CI,-11.80-45.85,P=0.25)and Clavien-Dindo grade ≥Ⅲ postoperative complications(17.1%vs23.1%,OR=0.73,95%CI,0.43-1.25,P=0.25).Recurrence rate was significantly lower in the NAT group(76.1%vs85.8%,OR=0.46,95%CI,0.28-0.75,P=0.002).Conclusions:1.NAT showes statistically significant advantage in OS;2.NAT reduce the tumor diameter and the rate of lymph node metastasis,thus increase the R0 resection rate;3.NAT reduce the rate of recurrence;4.NAT do not increase the operate time,intraoperative blood loss and grade ≥Ⅲ postoperative complications;5.NAT do not reduce the rate of overall resection and adjuvant therapy completion.