Clinical value of serum CA19-9 levels in evaluating resectability of pancreatic carcinoma

Abstract

Aim: To evaluate the clinical value of serum CA19-9 levels in predicting the respectability of pancreatic carcinoma according to receiver operating characteristic (ROC) curve analysis.

Methods: Serum CA19-9 levels were measured in 104 patients with pancreatic cancer which were possible to be resected according to the imaging. ROC curve was plotted for the CA19-9 levels. The point closest to the upper left-hand corner of the graph were chosen as the cut-off point. The sensitivity, specificity, positive and negative predictive values of CA19-9 at this cut-off point were calculated.

Results: Resectable pancreatic cancer was detected in 58 (55.77%) patients and unresectable pancreatic cancer was detected in 46 (44.23%) patients. The area under the ROC curve was 0.918 and 95% CI was 0.843-0.992. The CA19-9 level was 353.15 U/mL, and the sensitivity and specificity of CA19-9 at this cut-off point were 93.1% and 78.3%, respectively. The positive and negative predictive value was 84.38% and 90%, respectively.

Conclusion: Preoperative serum CA19-9 level is a useful marker for further evaluating the resectability of pancreatic cancer. Obviously increased serum levels of CA19-9 (> 353.15 U/mL) can be regarded as an ancillary parameter for unresectable pancreatic cancer.

Figure 1

Distribution of preoperative serum CA19-9 levels. The horizon marker is set according to the cut-off point of CA19-9 (353.15 U/mL).

Figure 2

ROC analysis of CA19-9. Perfect discrimination has a ROC plot passing through the upper left corner (100% sensitivity, 100% specificity). The closer the ROC plot to the upper left corner, the higher the overall accuracy of the test (AUC: 0.9-1 indicating excellent; 0.8-0.9 indicating very good; 0.7-0.8 indicating good; 0.6-0.7 indicating average; 0.5-0.6 indicating poor). The AUC of CA19-9 was 0.918.