Association of Promoter Methylation of <i>RUNX3</i> Gene with the Development of Esophageal Cancer: A Meta Analysis

<div><p>Background</p><p>Runt-related transcription factor 3 (<i>RUNX3</i>) is a member of the runt-domain family of transcription factors. Emerging evidence indicates that RUNX3 is a tumor suppressor gene in several types of human cancers including esophageal cancer. However, the association between <i>RUNX3</i> promoter methylation and esophageal cancer remains unclear. Here we conducted a systematic review and meta-analysis to quantitatively evaluate the effects of <i>RUNX3</i> promoter methylation on the incidence of esophageal cancer.</p><p>Methods</p><p>A detailed literature search was made on Medline, Pubmed and Web of Science for related research publications written in English and/or Chinese. Methodological quality of the studies was also evaluated. The data were extracted and assessed by two reviewers independently. Analysis of pooled data were performed, the odds ratios (OR) were calculated and summarized respectively.</p><p>Results</p><p>Final analysis of 558 patients from 9 eligible studies was performed. The result showed that <i>RUNX3</i> methylation was significantly higher in esophageal cancer than in normal squamous mucosa from the proximal resection margin or esophageal benign lesions (OR = 2.85, CI = 2.01–4.05, P<0.00001). The prevalence of lymph node involvement, tumor size (T1–T2 vs T3–T4) and histological grade was significantly greater in <i>RUNX3</i>-negative cases (<i>RUNX3</i> unmethylated groups) than in <i>RUNX3</i>-positive cases (OR = 0.25, CI = 0.14–0.43, P<0.00001). <i>RUNX3</i> methylation was significantly higher in esophageal adenocarcinoma (EAC) than Barrett’s esophagus (OR = 0.35, CI = 0.20–0.59, P<0.0001). In addition, the pooled HR for overall survival (OS) showed that decreased <i>RUNX3</i> expression was associated with worse survival in esophageal cancer (HR = 4.31, 95% CI = 2.57–7.37, P<0.00001).</p><p>Conclusions</p><p>The results of this meta-analysis suggest that <i>RUNX3</i> methylation is associated with an increased risk, progression as well as worse survival in esophageal cancer. <i>RUNX3</i> methylation, which induces the inactivation of <i>RUNX3</i> gene, plays an important role in esophageal carcinogenesis.</p></div

The funnel plots were largely symmetric suggesting there were no publication biases in the meta-analysis of <i>RUNX3</i> methylation/expression and clinicopathological features as well as overall survival respectively.

<p>The funnel plot from 6 studies comparing esophageal cancers and normal squamous mucosa (A). The funnel plot from 4 studies in determining <i>RUNX3</i> hypermethylation in advanced stage (T3–T4) and early stage (T1–T2) (B). The funnel plot from 2 studies in determining <i>RUNX3</i> hypermethylation in Barrett’s esophagus (BE) and esophageal adenocarcinoma (EAC) (C). The funnel plot from 4 studies in determining the relationship between <i>RUNX3</i> hypermethylation and overall survival (OS) in esophageal cancer (D).</p

The pooled OR from 6 studies including 347 esophageal cancers and 246 normal squamous mucosa OR = 2.85, CI = 2.01–4.05, P<0.00001.

<p>The pooled OR from 6 studies including 347 esophageal cancers and 246 normal squamous mucosa OR = 2.85, CI = 2.01–4.05, P<0.00001.</p

<i>RUNX3</i> methylation significantly higher in esophageal adenocarcinoma (EAC) than Barrett’s esophagus (BE), OR = 0.35, CI = 0.20–0.59, P<0.0001.

<p><i>RUNX3</i> methylation significantly higher in esophageal adenocarcinoma (EAC) than Barrett’s esophagus (BE), OR = 0.35, CI = 0.20–0.59, P<0.0001.</p

Forest plot of odds ratio (OR) in 263 patients pooled in 4 studies in serum/cancer tissues DNA from advanced stage, including tumor size (T1–T2 vs T3–T4), lymph node involvement, lymph and blood vessels metastasis, and recurrence in esophageal carcinomas.

<p>The prevalence of lymph node involvement, tumor size (T1–T2 vs T3–T4) and histological grade was significantly greater in <i>RUNX3</i>-negative cases (<i>RUNX3</i> unmethylated group) than in <i>RUNX3</i>-positive cases, OR = 0.25, CI = 0.14–0.43, P<0.00001.</p

All four included studies estimated the relationship between OS and <i>RUNX3</i> methylation/expression.

<p>The pooled HR for OS showed that decreased <i>RUNX3</i> expression was associated with worse survival in esophageal cancer, HR = 4.31, 95% CI = 2.57–7.37, P<0.00001.</p

Flow chart of study selection.

<p>Flow chart of study selection.</p