Significance Of Zic1Promoter Methylation In DNA Prepared From Plasma For Early Diagnosis Of Gastric Carcinoma

ObjectiveTo investigate the value of Zicl promoter methylation in DNA prepared from plasma as a novel molecular marker for early diagnosis of gastric carcinoma and cancerization monitoring.MethodMethylation-specific PCR (MSP) was used to detect the methylation status of Zic1promoter in DNA prepared from plasma samples taken from15healthy persons,22gastric intraepithelial neoplasia patients and30gastric cancer patients. Besides, we analyzed the correlation between the detection rate of plasma Zicl promoter methylation with clinical and pathological data of the gastric cancer patients and intraepithelial neoplasia patients. In addition, we investigate the significance of combining CEA and Zic1promoter methylation to diagnosis gastric cancer.Results1)67studied cases included15healthy control patients,22intraepithelial neoplasia patients and30gastric cancer patients, mean age (55.9±12.2) years,34cases of male and33cases of female.2) The detection rates of Zic1promoter methylation in plasma samples of healthy control group was0%,in intraepithelial neoplasia group, gastric cancer group, high grade intraepithelial neoplasia plus early stage of gastric cancer group were31.8%,50% and55.6%, respectively. They all were significantly higher than that in healthy control group (P＜0.05), and the specificity was100%. The positive predictive value of plasma Zicl promoter methylation to diagnosis intraepithelial neoplasia and gastric cancer was100%, negative predictive value was33.3%.3) The methylation status in gastric cancer group was not correlated with age, gender, tumor size, tumor site, tumor differentiation, lymph node metastasis, TNM staging, tumor invasion and Hp infection (P＜0.05).4) The sensitivity of CEA in gastric cancer group, intraepithelial neoplasia group and high grade intraepithelial neoplasia plus stage of gastric cancer group were21.4%,17.5%and16.7%, respectively. In all the three group above, the sensitivity of Zicl promoter methylation was significantly higher than CEA (P＜0.05). In addition, Zicl promoter methylation combined CEA (parallel test) can improve the sensitivity and be complementary.ConclusionThe detection rates of Zic1promoter methylation in DNA prepared from plasma has important significance for early screening of gastric carcinoma. However, it still needs further study to do blinding test to explore the value for clinical screening.Zicl promoter methylation combined CEA (parallel test) can improve the positive rate and specificity.