Prognostic Values of SUVmax Value of PET/CT and CA19-9 as Biologic Markers in Patients with Pancreatic Ductal Adenocarcinoma

Abstract

Among various prognostic factors of pancreatic cancer, most of clinical information before surgery is obtained by imaging modality. However tumor biologic characteristics also should be considered to decide treatment plan. Purpose of this study is to evaluate clinical usefulness of preoperative standard uptake value in 18F-fluorodeoxyglucose positron emission tomography and carbohydrate antigen as biologic markers for prognosis of resectable pancreatic ductal adenocarcinoma. 189 patients with pancreatic adenocarcinoma underwent preoperative FDG-PET testing were studied. SUVmax was calculated for each primary lesion. Patients who underwent neoadjuvant chemotherapy, R2 resection, and sequential resection were excluded. Analysis about correlation between SUVmax and clinicopathologic parameters was performed. C-tree statistical method was drawn to estimated cutoff values of SUVmax and CA19-9 for survival rate. Multivariate analysis was conducted to identify prognostic factors for overall survival. Median duration of overall survival was 26 months, five-year survival rate was 22.4%. C-tree analysis revealed the optimal cutoff values for SUVmax was 5.5 and that of CA19-9 was 150 about survival rate. When subjects were divided into three groups according to combination of SUVmax and CA19-9 values from C-tree (high group, SUVmax >5.5 and CA19-9>150, intermediate group and low group, SUVmax≤5.5 and CA19-9≤150), there was a significant 5YSR difference (5.6%, 24.3% and 36.5%, p < 0.001) The multivariate analysis revealed low BMI and high SUVmax and venous invasion were prognostic factor in overall survival. As biologic markers, SUVmax and CA19-9 are prognostic factors in pancreatic cancer patients. Especially, patients with high SUVmax and CA19-9 are not indication to upfront sugery.