[Plasma methylation-specific polymerase chain reaction as a diagnostic tool for esophageal cancer patients].

: This study was designed to perform methylation-specific polymerase chain reaction (MS-PCR) assay for p16, E-cadherin, and retinoic acid receptor beta genes on peripheral blood samples from patients with esophageal squamous cell cancers, and compare the results of MS PCR with conventional serum tumor markers and the CEA-specific reverse transcriptase polymerase chain reaction (RT-PCR) assay. Preoperative blood samples were obtained from 30 patients with esophageal cancer, and were subjected to MS PCR and RT-PCR assays. Eleven patients (37%) showed aberrant methylation of the promoter region of at least one gene. On the other hand, circulating tumor cells were detected in 11 patients (37%). There was no correlation between both results and conventional tumor markers. The MS-PCR and RT-PCR assays can serve as complementary diagnostic markers for screening and monitoring patients with esophageal cancers.