Abstract
Purpose Carcinoembryonic antigen (CEA) is cell-surface 180-200 kDa glycoprotein that is overexpressed in breast, stomach pancreas, lung, and colorectal cancers. CEA was first described in 1965 by Gold and Freedman and then serum CEA of colorectal cancer patients was first measured in 1969 by radioimmunoassay by Thomson. CEA is currently most widely used tumor marker in the clinic for management of colorectal cancer. Various CEA test kits have been developed and commercialized. CEA kits from different manufacturers might have different test results because of different reagents and protocol. The purpose of this study was to compare results of four commercial available CEA kits. Materials and Methods This study was designed to evaluate four commercially available CEA kits using serum samples acquired from 120 patients who visited our clinic. Test results were compared and analyzed according to the respective test methods. High concentration samples were diluted with saline and diluted solution. Results All of the four kits showed a significant correlation within the reference value. However, three of the four kits used for the dilution test using high concentration samples showed the hook effect. Conclusion Results of the present study showed that It is important to establish the standardized dilution standards for the high-concentration specimens to manage the error of the test result by the hook effect.