Establishment of reference intervals of tumor markers in Korean adults

Background : The sensitivity and specificity of tumor markers for detecting cancer could be significantly changed by the reference intervals of tumor markers. We established reference intervals of tumor markers in Korean adults and evaluated its importance, since the reference intervals recommended by the manufacturers were determined in the Caucasian population and have sometimes been adopted without verification. Methods : We established the reference intervals of alpha fetoprotein (AFP), carcinoembryonic antigen (CEA), cancer antigen (CA)125, carbohydrate antigen (CA)19-9, total prostate specific antigen (TPSA), cytokeratin fragment (Cyfra)21-1, and neuron specific enolase (NSE) according to the CLSI guideline in a maximum number of 1,364 healthy adults aged 20-60 yrs who visited a health promotion center from January to February 2007. Results : Reference intervals of all tumor markers except for AFP were not in agreement with those recommended by the manufacturers. Reference intervals of CEA, TPSA, CA 19-9, CA125, and Cyfra21-1 were age dependent. The mean reference values of NSE, CA125, and CEA were statistically different according to gender (11.72 vs 10.78 ng/mL, menopause status (18.89 vs 12.62 U/mL, and smoking status (2.60 vs 2.12 vs 1.80 ng/mL for smokers, past smokers, and non-smokers, respectively), respectively. Conclusions : With the verification and establishment of reference intervals of tumor markers in a Korean local population, we found the reference intervals significantly different by either age, gender, smoking or menopause status.