Circulating Tumor Cells and Aberrant Methylation as Tumor Markers in Patients with Esophageal Cancer

Background: This study was designed to compare the detection rates of conventional tumor markers with two molecular diagnostic approaches on blood samples from patients with esophageal squamous cell cancer. Materials and Methods: Preoperative blood samples were obtained from 44 esophageal cancer patients and were subjected to CEA-specific reverse transcriptase-polymerase chain reaction (RT-PCR) assay and methylation-specific polymerase chain reaction (MSP) assay for p16, E-cadherin and RARβ genes. Results: Circulating tumor cells were detected in 12 patients (27%); 14 patients (32%) had aberrant methylation in the promoter region of at least one gene (6, 4 and 4 patients, for p16, E-cadherin and RARβ, respectively). No abnormality was detected by either assay in control plasmas. Altogether, 23 patients (53%) had a positive result in either molecular assay. There was no correlation between either assay result and those of conventional serum markers. Conclusion: The RT-PCR and MSP assays can serve as complementary markers for screening and monitoring esophageal cancer patients.