Clinical value of serum cancer antigen 19-9 as a tumor screening marker among healthy individuals.

PURPOSE To investigate the clinical value of serum cancer antigen 19-9 (CA 19-9) as a tumor screening marker among healthy individuals. METHODS CA 19-9 levels were measured in 1921 healthy individuals and were compared to reference values. Analysis based on gender was also carried out. Individuals who had higher CA 19-9 values were advised to undergo imaging examinations and start follow-up. The incidence rate of tumors in these individuals and their prognoses were monitored. RESULTS High CA 19-9 levels were found in 30 -1.5%- individuals without tumor diagnosis at that time. The overall positive detection rate was 15.62 per 1000 population; the rate was higher in males than in females -9.29 and 32.56 per 1000 population, respectively; p<0.01-. Tumors were diagnosed in 7 -0.36%)cases -6 men and 1 woman-; 6 of 30 individuals had CA 19-9 levels that were 5-fold higher than the highest reference value, without tumor specificity. CONCLUSION CA 19-9 has a low positive rate and is non-specific; routine screening is not recommended for healthy individuals.