Background/aims: Recently, Herfarth et al. reported that a subset of colorectal cancers was characterized by a specific methylation pattern in the MGMT promoter associated with reduced MGMT expression.
Methodology: Methylation status of the MGMT gene was examined in primary carcinomas and the corresponding normal tissues derived from 48 patients with colorectal cancer using quantitative methylation-specific PCR (qMSP) and the correlation between the methylation status and the clinicopathological findings was evaluated.
Results: Aberrant methylation of the MGMT gene was detected in 10 out of the 48 (21%) primary colorectal cancers. The present study results suggested that the aberrant methylation of the MGMT gene was specific and frequently observed in colorectal cancers. The clinicopathological data were correlated with the methylation results. No significant correlations were observed between the presentation of abnormal methylation in the colorectal carcinomas and patient gender or age, maximal tumor size, tumor extent, tumor site, histology, lymph node metastasis, and Dukes stage.
Conclusion: All stages of colorectal cancers presented MGMT methylation, indicating that the MGMT gene has been methylated from the early stages of colorectal cancers.