Serum CA 19.9 Levels in Patients With Benign and Malignant Disease: Correlation With the Serum Protein Electrophoretic Pattern

Aim: To confirm that the carbohydrate antigen 19.9 (CA 19.9) protein can be evaluated by determining changes in the beta 2 zone in protein electrophoresis. Materials and Methods: A total of 75 patients (64 with cancer, 11 with benign diseases) with abnormal serum CA 19.9 level were included. Results: Patients with cancer had significantly higher serum CA 19.9 concentrations than those with benign diseases (p < 0.001). Similar CA 19.9 levels were observed in patients with normal (median 1129 U/ml), weakly positive (median 699 U/ml) and positive (2333 U/ml) beta 2 fraction in protein electrophoresis. In contrast, changes in the protein pattern of the beta 2 fraction were related to an inflammatory pattern with significantly higher C-reactive protein concentration (p < 0.0001), independently of serum CA 19.9 level. Conclusion: The intensity of the beta 2 fraction in protein electrophoresis is related to inflammation and not to CA 19.9 in patients with cancer or other diseases.