Methylation Status of MGMT Gene Promoter in Patients with Adenocarcinoma of Esophagogastric Junction and Its Relationship with Prognosis

Objective To detect the methylation status of O⁶-methylguanine-DNA methyltransferase (MGMT) promoter and its protein expression in adenocarcinoma of esophagogastric junction (AEJ) tissues. The relationship of MGMT methylation status and its protein expression with clinical features and survival were also analyzed.

Methods The methylation status of MGMT promoter was detected by methylation specific polymerase chain reaction (MSP) in 107 AEJ cases. Immunohistochemistry staining was used to detect protein expression in the same group of specimen. Then, the relationship of MGMT methylation with clinical features and prognosis were analyzed.

Results The promoter methylation rate of MGMT in cancerous specimen was higher than that in adjacent normal group. However, the MGMT expression rate was opposite. A correlation between promoter methylation of MGMT and protein expression were established by Spearman correlation analysis. MGMT promoter methylation and its protein expression had significant correlation with lymph node metastasis and pTNM stage. The Cox multivariate regression analysis indicated that MGMT promoter methylation, MGMT protein expression and pTNM stage were significant risk factors.

Conclusion The promoter methylation of MGMT, MGMT protein expression and pTNM stage might be significant influence factors for 5 years survival time of AEJ patients.