TNM stage I pancreatic ductal adenocarcinoma patients without pathological risk may drive limited benefit from adjuvant chemotherapy

Objective In this study, we identified pathological risk factors as key determinants of whether patients with pancreatic ductal adenocarcinoma (PDAC) can benefit from adjuvant chemotherapy following radical resection. Methods This single-center retrospective study enrolled 520 patients who underwent curative-intent resection for pancreatic ductal adenocarcinoma between 2011 and 2018. To minimize potential selection bias and confounding effects, propensity score matching (PSM) was performed using a 1:2 nearest-neighbor matching algorithm without replacement, with a caliper of 0.2 standard deviations of the logit propensity score. After matching, the patients were stratified based on the presence or absence of pathological risk factors, allowing for a comprehensive evaluation of how these factors influence the efficacy of adjuvant chemotherapy. Results Based on the analysis for the whole study, the results showed that adjuvant chemotherapy could significantly improve the overall survival (OS) ( p < 0.001) and recurrence-free survival (RFS) ( p < 0.001). However, for patients in Tumor-Node-Metastasis (TNM) stage I without pathological risk factors, postoperative adjuvant chemotherapy did not significantly prolong the OS (median OS: NA vs.50.0 months, p = 0.365) and RFS (median RFS: 24 months vs.44 months, p = 0.569); for patients with pathological risk factors, adjuvant chemotherapy can significantly improve the OS (median OS: 28.0 months vs.17.0 months, p < 0.001) and RFS (median RFS: 21.0 months vs.7.0 months, p = 0.004). Conclusion The results of this study indicate that pathological risk factors play a key role in postoperative adjuvant chemotherapy for PDAC patients in TNM stage I. For patients in TNM stage I who harbored pathological risk factors, postoperative adjuvant chemotherapy was associated with a significant survival benefit. However, among those without pathological risk factors, no statistically significant association was observed between adjuvant chemotherapy and improved survival outcomes.