Postoperative serum tumor markers-based nomogram predicting early recurrence for patients undergoing radical resections of pancreatic ductal adenocarcinoma

BACKGROUND Early recurrence(ER)is associated with dismal outcomes in patients undergoing radical resection for pancreatic ductal adenocarcinoma(PDAC).Approaches for predicting ER will help clinicians in implementing individualized adjuvant therapies.Postoperative serum tumor markers(STMs)are indicators of tumor progression and may improve current systems for predicting ER.AIM To establish an improved nomogram based on postoperative STMs to predict ER in PDAC.METHODS We retrospectively enrolled 282 patients who underwent radical resection for PDAC at our institute between 2019 and 2021.Univariate and multivariate Cox regression analyses of variables with or without postoperative STMs,were performed to identify independent risk factors for ER.A nomogram was constructed based on the independent postoperative STMs.Receiver operating characteristic curve analysis was used to evaluate the area under the curve(AUC)of the nomogram.Survival analysis was performed using Kaplan-Meier survival plot and log-rank test.RESULTS Postoperative carbohydrate antigen 19-9 and carcinoembryonic antigen levels,preoperative carbohydrate antigen 125 levels,perineural invasion,and pTNM stage III were independent risk factors for ER in PDAC.The postoperative STMs-based nomogram(AUC:0.774,95%CI:0.713-0.835)had superior accuracy in predicting ER compared with the nomogram without postoperative STMs(AUC:0.688,95%CI:0.625-0.750)(P=0.016).Patients with a recurrence nomogram score(RNS)>1.56 were at high risk for ER,and had significantly poorer recurrence-free survival[median:3.08 months,interquartile range(IQR):1.80-8.15]than those with RNS≤1.56(14.00 months,IQR:6.67-24.80),P<0.001).CONCLUSION The postoperative STMs-based nomogram improves the predictive accuracy of ER in PDAC,stratifies the risk of ER,and identifies patients at high risk of ER for tailored adjuvant therapies.