RETRACTED: Meta-analysis of the association between GSTT1 null genotype and risk of nasopharyngeal carcinoma in Chinese (Retracted article. See April, 2017)

Glutathione S-transferase T1 (GSTT1) null genotype has been proven to be associated with risks of many cancers. There were also many studies assessing on the association between GSTT1 null genotype and nasopharyngeal carcinoma risk in Chinese, but the findings from those studies were inconsistent. We performed a meta-analysis to provide a more precise assessment on the effect of GSTT1 null genotype on nasopharyngeal carcinoma risk. The PubMed and Wanfang databases were searched to identify eligible case-control studies on the association between GSTT1 null genotype and risk of nasopharyngeal carcinoma in Chinese. The pooled odds ratios (OR) with corresponding 95 % confidence intervals (95 % CI) were used to assess the association. Eight case-control studies with a total of 3,702 individuals were finally included in the meta-analysis. Meta-analysis of a total of eight studies showed that GSTT1 null genotype was significantly associated with increased risk of nasopharyngeal carcinoma in Chinese (OR = 2.27; 95 % CI 1.41-3.67; P = 0.001). The finding from cumulative meta-analysis showed that there was a trend of more obvious association between GSTT1 null genotype and risk of nasopharyngeal carcinoma in Chinese as data accumulated by publication year. Therefore, the GSTT1 null genotype is significantly associated with increased risk of nasopharyngeal carcinoma in Chinese.