Prognostic Accuracy of ypTNM Stage in Patients with Pancreatic Cancer in the Era of Modern Neoadjuvant Therapy

Background: The American Joint Committee on Cancer (AJCC) 8th edition TNM staging manual, which provided ypTNM for patients undergoing neoadjuvant therapy (NAT), has not been comparatively assessed against pTNM for prognosis in pancreatic cancer. This study aimed to compare the prognosis between ypTNM and pTNM stages. Patients and Methods: Clinicopathological data from 586 patients who underwent pancreatic cancer surgery at a tertiary center between 2018 and 2022 were analyzed to compare survival outcomes between ypTNM and pTNM stages and identify prognostic factors. Results: The analysis included 541 patients (100 ypTNM, 441 pTNM). Significant differences in overall survival (OS) were observed among patients stratified by TNM stage (p < 0.001). However, no significant difference in OS was found between the ypTNM and pTNM groups (2-year survival rate (YSR): 76.8% vs. 66.7%, p = 0.094). Subgroup analysis by stage I (82.4% vs. 76.2%, p = 0.577) and II (68.8% vs. 61.6%, p = 0.715), and III (53.0% vs. 49.8%, p = 0.596) revealed similar survival rates. Multivariate analysis identified factors associated with OS: age > 65 years (HR 1.763, p < 0.001), CA19-9 > 150 U/mL (HR 1.439, p = 0.014), preoperative biliary drainage (HR 1.405, p = 0.029), pathologic T2 stage (HR 1.961, p = 0.004) and T3/4 stage (HR 2.830, p < 0.001) versus T0/1 stage, lymphovascular invasion (HR 2.220, p < 0.001), and adjuvant treatment (HR 0.251, p < 0.001). Conclusions: This study confirms comparable survival outcomes between ypTNM and pTNM stages in surgically resected pancreatic cancer, affirming the applicability of the TNM staging system after NAT. The results highlight the utility of TNM staging in guiding therapeutic decisions for patients undergoing NAT.