Meta-regression analysis in cancer vs. control.

<p>Meta-regression analysis in cancer vs. control.</p

The Correlation of <i>MGMT</i> Promoter Methylation and Clinicopathological Features in Gastric Cancer: A Systematic Review and Meta-Analysis

<div><p>The silencing of the tumor suppressor gene O-6-methylguanine-DNA methyltransferase (<i>MGMT</i>) by promoter methylation commonly occurs in human cancers. The relationship between <i>MGMT</i> promoter methylation and gastric cancer (GC) remains inconsistent. This study aimed to evaluate the potential value of <i>MGMT</i> promoter methylation in GC patients. Electronic databases were searched to identify eligible studies. The pooled odds ratio (OR) and the corresponding 95% confidence interval (95% CI) were used to evaluate the effects of <i>MGMT</i> methylation on GC risk and clinicopathological characteristics. In total, 31 eligible studies including 2988 GC patients and 2189 nonmalignant controls were involved in meta-analysis. In the pooled analysis, <i>MGMT</i> promoter methylation was significantly associated with GC risk (OR = 3.34, P < 0.001) and substantial heterogeneity (P < 0.001). Meta-regression and subgroup analyses based on the testing method, sample material and ethnicity failed to explain the sources of heterogeneity. Interestingly, <i>MGMT</i> methylation showed a trend associated with gender, and methylation is lower in males compared with females (OR = 0.76, 95% CI = 0.56–1.03). We did not find a significant association in relation to tumor types, clinical stage, age status or <i>H</i>. <i>pylori</i> status in cancer (all P > 0.1). <i>MGMT</i> promoter methylation may be correlated with the prognosis of GCs in disease free survival (DFS) or overall survival (OS) for univariate analysis. <i>MGMT</i> promoter methylation may play a crucial role in the carcinogenesis and prognosis of GC. <i>MGMT</i> methylation was not correlated with tumor types, clinical stage, age status, <i>H</i>. <i>pylori</i> status. However, the result of the association of <i>MGMT</i> methylation and gender should be considered with caution.</p></div

The correlation of <i>MGMT</i> promoter methylation and clinicopathological features.

<p>The correlation of <i>MGMT</i> promoter methylation and clinicopathological features.</p

The summary of OR in cancer vs. control.

<p>The summary of OR in cancer vs. control.</p

Forest plot of the correlation between <i>MGMT</i> methylation and gender.

<p>Forest plot of the correlation between <i>MGMT</i> methylation and gender.</p

Flow chart of the literature search strategy.

<p>Flow chart of the literature search strategy.</p

Forest plot of the correlation between <i>MGMT</i> methylation and GC.

<p>Forest plot of the correlation between <i>MGMT</i> methylation and GC.</p