Ye Zheng, Parry James M
Data Mining Group, Department of Computing, Imperial College London, UK.
Med Sci Monit. 2003 Oct;9(10):SR83-91.
Glutathione S-transferase M1 is an important phase II enzyme involved in the detoxification of many environmental carcinogens. It has been postulated that individuals with GSTM1 deficiency have increased susceptibility to carcinogens and are more likely to develop cancer. GSTM1 status has been extensively studied as a colon cancer risk factor, although published studies have produced conflicting results. To re-examine this controversy, we have undertaken a meta-analysis investigating the relationship of GSTM1 status and colon cancer risk.
MATERIAL/METHODS: Odds ratio was employed to evaluate the risk of colon cancer and GSTM1 status. To take into account the possibility of heterogeneity across the studies, a statistical test for heterogeneity across the studies was performed. The summary odds ratios were assessed by calculating a weighted average of odds ratios for all of the studies.
The pooled odds ratio of colon cancer risk associated with the GSTM1 deficiency is 0.99 (95% CI: 0.91-1.07). If pooling studies were based on the genotyping method, the overall odds ratio of colon cancer risk associated with the GSTM1 deficiency showed no difference. Moreover, the relationship of GSTM1 deficiency and colon cancer risk was also conducted on the specific ethnic groups and tumour site.
The results of our meta-analysis does not support the hypothesis that GSTM1 alone is an important risk factor for colon cancer, and suggests that GSTM1 status has no effect on the risk of developing colon cancer.
谷胱甘肽S-转移酶M1是一种重要的Ⅱ相酶，参与多种环境致癌物的解毒过程。据推测，谷胱甘肽S-转移酶M1缺乏的个体对致癌物的易感性增加，患癌可能性更高。谷胱甘肽S-转移酶M1状态作为结肠癌的一个风险因素已得到广泛研究，尽管已发表的研究结果相互矛盾。为重新审视这一争议，我们进行了一项荟萃分析，以研究谷胱甘肽S-转移酶M1状态与结肠癌风险之间的关系。
材料/方法：采用比值比来评估结肠癌风险和谷胱甘肽S-转移酶M1状态。为考虑研究间异质性的可能性，对研究间的异质性进行了统计检验。通过计算所有研究比值比的加权平均值来评估汇总比值比。
与谷胱甘肽S-转移酶M1缺乏相关的结肠癌风险合并比值比为0.99（95%可信区间：0.91 - 1.07）。如果根据基因分型方法汇总研究，与谷胱甘肽S-转移酶M1缺乏相关的结肠癌风险总体比值比无差异。此外，还针对特定种族群体和肿瘤部位对谷胱甘肽S-转移酶M1缺乏与结肠癌风险的关系进行了研究。
我们的荟萃分析结果不支持谷胱甘肽S-转移酶M1单独是结肠癌重要风险因素的假设，并表明谷胱甘肽S-转移酶M1状态对患结肠癌的风险没有影响。
