摘要Objective:The aim of the current study was to identify independent prognostic factors,evaluate differential adjuvant chemotherapy efficacy across clinicopathologic subgroups,and define adjuvant chemotherapy-sensitive populations.Methods:A retrospective analysis of 168 AAC patients undergoing curative pancreaticoduodenectomy(2011-2020)was performed.Cases were classified into intestinal(28.0％),pancreatobiliary(30.4％),and mixed subtypes(18.5％)per NCCN(v2.2025)criteria.Independent prognostic factors for AAC patients were identified through uni-and multi-variable Cox proportional hazards modeling and subgroup analyses were stratified by age range,gender,differentiation,T stage,N stage,BVI,TDs,and PNI.Results:The pancreatobiliary signature(HR=2.884,P＜0.001)and BVI(HR=2.330,P=0.001)were independent poor prognostic factors.Adjuvant chemotherapy improved overall survival(OS)in the following AAC patients:T3-T4 stage(HR=0.485,P=0.050);N1-N2 stage(HR=0.365,P=0.008);and TD-positive(HR=0.401,P=0.026).The median OS increased from 22.3-51.3 months with adjuvant chemotherapy in TD-positive patients(P=0.019).TD positivity conferred a worse prognosis in BVI-negative subgroups(OS:HR=3.840,95％CI:2.058-7.166,P＜0.001;and progression-free survival(PFS):HR=2.950,95％CI:1.550-5.617,P=0.002).Conclusions:The pancreatobiliary signature and BVI constitute critical high-risk pathologic features in AAC.TD status identified high-risk cohorts,thus enabling postoperative risk-stratified treatment strategies.In patients negative for pancreatobiliary signature or BVI,TD positivity predicted significantly worse survival.