Comparison of serum aberrant methylation and conventional tumor markers in gastric cancer patients

BACKGROUND/AIMS: This study was designed to compare a methylation-specific polymerase chain reaction (MSP) assay for three genes [p16, E-cadherin, and retinoic acid receptor beta (RARbeta)] and conventional serum tumor markers using blood samples from gastric cancer patients. METHODOLOGY: Preoperative blood samples obtained from 63 consecutive patients with gastric cancer were subjected to MSP and conventional serum marker assays. RESULTS: MSP assay detected hypermethylation of p16 in 17 patients (27%), E-cadherin in 15 patients (24%), and RARbeta in 11 patients (17%). Altogether, 32 patients (51%) showed hypermethylation in serum samples. By contrast, only 21 (33%) patients exhibited elevations of serum carcinoembryonic antigen or carbohydrate antigen 19-9. There was no correlation between MSP results and conventional tumor markers. CONCLUSIONS: The detection rate for MSP was higher than that of conventional tumor markers in serum of gastric cancer patients. Both assays can serve as complementary markers that allow for selection of cases requiring more intensive screening or aggressive postoperative treatment.