Cohypermethylation of p14 in combination with CADM1 or DCC as a recurrence-related prognostic indicator in stage i esophageal squamous cell carcinoma

BACKGROUND: The objective of this study was to discover molecular biomarkers associated with the recurrence of esophageal squamous cell carcinoma (ESCC). METHODS: The authors retrospectively analyzed the hypermethylation status of 11 genes using methylation-specific polymerase chain reaction (PCR) and the expression of epidermal growth factor receptor (EGFR), O-6 methylguanine-DNA methyltransferase (MGMT), tumor protein 53 (p53), and transforming growth factor β (TGFβ) using immunohistochemistry in 329 formalin-fixed, paraffin-embedded ESCCs. RESULTS: Recurrence was identified in 151 of 329 ESCCs (46%) at a median follow-up of 4.5 years. The recurrence was associated with hypermethylation of the genes cell adhesion molecule 1 (CADM1) (P =.003), deleted in colon carcinoma (DCC) (P =.04), or cyclin-dependent kinase inhibitor 2A (p14) (P =.02) in patients with stage I ESCC. Thirty-six of 37 Stage I ESCCs (97%) that had cohypermethylation of at least 2 of the 3 genes had hypermethylation of p14 plus either CADM1 or DCC or both CADM1 and DCC. The 5-year recurrence-free survival (RFS) rates were 93% in patients who had stage I disease without hypermethylation of the 3 genes and 56% in those who had cohypermethylation of p14 in combination with CADM1 and/or DCC. Patients who had stage I ESCC with cohypermethylation of p14 in combination with DCC and/or CADM1 had 7.13 times (95% confidence interval, 1.61-31.64 times; P =.009) poorer RFS compared with those who had no hypermethylation of the 3 genes after adjusting confounding factors. Hypermethylation of the other 8 genes and altered expression of 4 proteins were not associated with recurrence across pathologic stages. CONCLUSIONS: The current results suggested that cohypermethylation of p14 in combination with DCC and/or CADM1 may be an independent prognostic factor for recurrence in patients with stage I ESCC.