Background: Carbohydrate antigen 15-3 (CA15-3), Kerbs von den Lungen (KL-6) and breast cancer antigen 225 (BCA225) are widely used tumor markers for breast and lung cancer respectively.
Patients and methods: We analyzed 460 Japanese volunteers for 99 items on blood examination including 27 serum tumor markers. Correlations between 27 tumor markers and the other items were statistically analyzed.
Results: Positive correlations were identified between CA15-3 vs. KL-6, CA15-3 vs. BCA225, and KL-6 vs. BCA225, with correlation coefficients of 0.84, 0.86, and 0.79, respectively.
Conclusion: This is the first report to show a positive correlation among these markers in the general population. All of these are recognized as belonging to the mucin family, and this might be the reason for the positive correlation.