MGMT and non-small cell lung carcinoma: The databases of Medline, EMBSE, CNKI and Wanfang were searched for selection of published articles of MGMT gene promoter methylation and non-small cell lung carcinoma risk.The pooled odds ratio (OR) and percentage of MGMT for lung cancer tissue of NSCLC patients compared with normal lung tissue, plasma and the bronchial lavage fluid were pooled.