Elevated serum CA19-9 level is a promising predictor for poor prognosis in patients with resectable pancreatic ductal adenocarcinoma: a pilot study

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive human cancers. Several studies have reported that the carbohydrate antigen 19-9 (CA19-9) level is a useful marker for predicting the prognosis for PDAC after resection. However, the cutoff value of CA19-9 used to predict prognosis varied among these reports. The aims of this study were to evaluate whether the serum CA19-9 level is a significant predictor for survival and to determine the optimal cutoff value of CA19-9 for predicting prognosis. Methods: A total of 120 consecutive patients who underwent surgery for potentially resectable primary PDAC were retrospectively analyzed. The variables included the following: age, sex, the location of the tumor, the maximal tumor size, the histological differentiation, the margin status, the tumor stage, serum CA19-9 levels, and serum total bilirubin (TBil) levels. Results: The overall 1-year survival rate was 62.5%. The receiver operating characteristic (ROC) curve indicated a significant result for the level of CA19-9 in predicting death within 1 year after surgery (Area under the curve (AUC), 0.612; 95% confidence interval (CI), 0.505-0.720; P=0.040). The optimal cutoff point was 338.45 U/mL (sensitivity, 60.0%; specificity, 66.7%; accuracy, 64.2%). The strongest univariate predictor among the categorized CA19-9 values was CA19-9 greater than or equal to 338.45 U/mL. In the multivariate Cox proportional hazards mode analysis, the serum CA19-9 level, age and the histological differentiation were significant independent prognostic factors that were associated with the overall survival. Conclusions: The preoperative elevated CA19-9 level is a promising independent factor for predicting a poor prognosis in PDAC, and the optimal cutoff value is 338.45 U/mL.