Supplementary Material for: Clinical Significance of O-6-Methylguanine-DNA-Methyltransferase Promoter Methylation in Patients with Esophageal Carcinoma: A Systematic Meta-Analysis

2017-12-19T15:38:28Z (GMT) by Zhang Y. Tong T.
<p><b><i>Background:</i></b> The correlation between O-6-methylguanine-DNA-methyltransferase (<i>MGMT</i>) promoter methylation and esophageal cancer remains controversial. This study was conducted to evaluate the clinical effect of <i>MGMT</i> promoter methylation on esophageal carcinoma patients. <b><i>Methods:</i></b> A literature search was conducted in the PubMed, EMBASE, EBSCO, and Cochrane Library databases. The overall OR and corresponding 95% CI were calculated using the random-effects model. <b><i>Results:</i></b> Finally, 17 eligible studies were identified in this meta-analysis; these studies included a total of 1,368 patients with esophageal carcinoma and 1,489 with nonmalignant controls. <i>MGMT</i> promoter methylation was significantly higher in esophageal carcinoma tissue samples than in nonmalignant tissue samples (OR 3.64, <i>p</i> < 0.001). Promoter methylation of the <i>MGMT</i> gene was not associated with gender, cigarette smoking, drinking behavior, or tumor differentiation, but <i>MGMT</i> promoter methylation was correlated with age (≥60 vs. <60 years: OR 1.64, <i>p</i> = 0.028), lymph node status (positive status vs. negative status: OR 2.39, <i>p</i> = 0.024), and clinical stage (stages 3-4 vs. 1-2: OR 10.59, <i>p</i> < 0.001). <b><i>Conclusions:</i></b> Our findings suggest that <i>MGMT</i> promoter methylation may be correlated with esophageal cancer carcinogenesis and could be associated with age, lymph node status, and clinical stage.</p>