La Torre Giuseppe, Boccia Stefania, Ricciardi Gualtiero
Institute of Hygiene, Catholic University Medical School, L.go F.Vito, 1-00168 Rome, Italy.
Cancer Lett. 2005 Jan 10;217(1):53-60. doi: 10.1016/j.canlet.2004.08.020.
Susceptibility to gastric cancer may be in part attributable to inter-individual variability in metabolic activation or detoxification of carcinogens, and in this context the polymorphic GSTM1 gene has been extensively studied. Seventeen reports detailing a possible association between GSTM1 deletion and gastric cancer have been published so far. In order to examine the risk of gastric cancer associated with GSTM1 null genotype, a meta-analysis of published case-control studies was undertaken using a random effect model. Two studies were excluded because some data were missing in the results. The principal outcome measure was the odds ratio for the risk of gastric cancer. Pooling all the 15 studies identified, the overall odds ratio of gastric cancer risk associated with GSTM1 deficiency was 1.24 (95% confidence interval, 1.00-1.54). Furthermore, by pooling four studies detailing the possible interaction between GSTM1 status smoking habits and gastric cancer risk, an overall estimate of odds ratio of 2.93 (95% confidence interval, 1.56-5.47) for ever smokers with GSTM1 deficiency compared to non-smokers with GSTM1 normal genotype has emerged. These results suggest that GSTM1 status probably has no effect on the risk of gastric cancer per se, but may modulate tobacco-related carcinogenesis of gastric cancer. Greater attention should therefore be paid to the design of future studies: only well designed population-based control studies considering all the possible confounding risk factors and based on a sample size commensurate with the detection of small genotypic risk may allow a more definitive conclusion.
胃癌易感性可能部分归因于个体间致癌物代谢激活或解毒的差异，在此背景下，多态性GSTM1基因已得到广泛研究。迄今为止，已有17篇报告详细阐述了GSTM1缺失与胃癌之间可能存在的关联。为了研究与GSTM1无效基因型相关的胃癌风险，我们采用随机效应模型对已发表的病例对照研究进行了荟萃分析。两项研究被排除，因为结果中缺少一些数据。主要结局指标是胃癌风险的比值比。汇总所有确定的15项研究，与GSTM1缺乏相关的胃癌风险总体比值比为1.24（95%置信区间，1.00 - 1.54）。此外，通过汇总四项详细阐述GSTM1状态、吸烟习惯与胃癌风险之间可能相互作用的研究，与GSTM1正常基因型的非吸烟者相比，GSTM1缺乏的既往吸烟者的总体比值比估计为2.93（95%置信区间，1.56 - 5.47）。这些结果表明，GSTM1状态本身可能对胃癌风险没有影响，但可能会调节与烟草相关的胃癌致癌作用。因此，未来的研究设计应更加受到关注：只有精心设计的基于人群的对照研究，考虑到所有可能的混杂风险因素，并基于与检测小基因型风险相适应的样本量，才可能得出更明确的结论。
