Preoperative CA19­9 level and dual time point FDG­PET/CT as strong biological indicators of borderline resectability in pancreatic cancer: A retrospective study.

ABSTRACT

Tumor resectability, which is increasingly determined based on preoperative chemotherapy, is critical in determining the best treatment for pancreatic cancers. The present study evaluated the usefulness of serum carbohydrate antigen 19-9 (CA19-9) and the preoperative 8F-fluorodeoxyglucose positron emission tomography/computed tomography standardized uptake value (SUV) percentage change (SUVmax%=[(SUVmax2-SUVmax1)/SUVmax1] ×100, where SUVmax1 and SUVmax2 represent the initial and delayed phases, respectively) as biological factors indicative of tumor resectability. The present study included patients with resectable pancreatic cancer who underwent complete surgical resection, for whom both CA19-9 and SUVmax% were documented using cut-off values of 500 U/ml and 24.25%, respectively. Patients were classified as follows i) High CA19-9 and SUVmax% both CA19-9 and SUVmax% were elevated; ii) high CA19-9 or SUVmax% either CA19-9 or SUVmax% were elevated; or iii) low CA19-9 and SUVmax% neither value met the cut-off. Relapse-free survival (RFS) and overall survival (OS) were calculated, for which univariate and multivariate analyses were performed. Of the 86 patients included, 39 were classified as high CA19-9 or SUVmax% and 12 as high CA19-9 and SUVmax%, with the former group having a significantly worse RFS (vs. low CA19-9 and SUVmax%; P<0.001; vs. high CA19-9 or SUVmax%; P=0.011) and OS (vs. low CA19-9 and SUVmax%, P=0.002; vs. high CA19-9 or SUVmax%, P<0.001). Therefore, high CA19-9 and SUVmax% was an independent predictor of worse RFS (P<0.001) and OS (P=0.003). In conclusion, CA19-9 and SUVmax% can be utilized as biological indicators of resectability.