First Department of Respiratory Medicine, Nanjing Chest Hospital, 215 Guangzhou Road, Nanjing 210029, China.
J Exp Clin Cancer Res. 2011 Oct 20;30(1):99. doi: 10.1186/1756-9966-30-99.
Many studies have examined the association between the CYP1A1 MspI and exon 7 gene polymorphisms and lung cancer risk in various populations, but their results have been inconsistent.
To assess this relationship more precisely, a meta-analysis and review were performed. The PubMed, Embase, Web of Science, and CNKI database was searched for case-control studies published up to June 2010. Data were extracted and pooled odds ratios (OR) with 95% confidence intervals (CI) were calculated.
Ultimately, 64 studies, comprising 18,397 subjects from 49 case-control studies of the MspI genotype and 18,518 patients from 40 case-control studies of the exon 7 genotype, were included. A significantly elevated lung cancer risk was associated with 2 MspI genotype variants (for type C vs. Type A: OR = 1.26, 95% CI = 1.12-1.42; for types B and C combined vs. Type A: OR = 1.20, 95% CI = 1.13-1.28) in overall population. In the stratified analysis, a significant association was found in Asians, Caucasians, lung SCC, lung AC and Male population, not in mixed population, lung SCLC and female population. However, inconsistent results were observed for CYP1A1 exon7 in our meta-analysis, two variants of the exon 7 polymorphism were associated with a significantly higher risk for lung cancer (for Val/Val vs. Ile/Ile: OR = 1.24, 95% CI = 1.09-1.42; for (Ile/Val +Val/Val) vs. Ile/Ile: OR = 1.15, 95% CI = 1.07-1.24) in overall population. In the stratified analysis, a significant assocation was found in Asians, Caucasians, lung SCC and Female population, not in mixed population, lung AD, lung SCLC and Male population. Additionally, a significant association was found in smoker population and not found in non-smoker populations for CYP1A1 MspI and exon7 gene.
This meta-analysis suggests that the MspI and exon 7 polymorphisms of CYP1A1 correlate with increased lung cancer susceptibility and there is an interaction between two genotypes of CYP1A1 polymorphism and smoking, but these associations vary in different ethnic populations, histological types of lung cancer and gender of case and control population.
许多研究已经检验了 CYP1A1 MspI 和外显子 7 基因多态性与肺癌风险之间的关联，但结果并不一致。
为了更准确地评估这种关系，我们进行了荟萃分析和综述。我们检索了 PubMed、Embase、Web of Science 和中国知网数据库，以获取截至 2010 年 6 月发表的病例对照研究。提取数据并计算合并的比值比（OR）及其 95%置信区间（CI）。
最终纳入了 64 项研究，其中包括 49 项 MspI 基因型病例对照研究的 18397 例患者和 40 项外显子 7 基因型病例对照研究的 18518 例患者。总体人群中，两种 MspI 基因型变异（对于 C 型 vs. A 型：OR = 1.26，95%CI = 1.12-1.42；对于 B 型和 C 型联合 vs. A 型：OR = 1.20，95%CI = 1.13-1.28）与肺癌风险升高显著相关。在分层分析中，在亚洲人、高加索人、肺鳞癌、肺腺癌和男性人群中存在显著相关性，但在混合人群、肺小细胞癌和女性人群中则无显著相关性。然而，我们的荟萃分析结果显示 CYP1A1 外显子 7 无显著相关性，外显子 7 多态性的两种变异与肺癌风险显著升高相关（对于 Val/Val vs. Ile/Ile：OR = 1.24，95%CI = 1.09-1.42；对于（Ile/Val + Val/Val）vs. Ile/Ile：OR = 1.15，95%CI = 1.07-1.24）。在分层分析中，在亚洲人、高加索人、肺鳞癌和女性人群中存在显著相关性，但在混合人群、肺腺癌、肺小细胞癌和男性人群中则无显著相关性。此外，在吸烟者人群中发现 CYP1A1 MspI 和外显子 7 基因与肺癌易感性增加相关，但在非吸烟者人群中则未发现这种相关性。
本荟萃分析提示 CYP1A1 的 MspI 和外显子 7 多态性与肺癌易感性增加相关，且两种 CYP1A1 多态性基因型与吸烟之间存在交互作用，但这些相关性在不同种族人群、肺癌组织学类型和病例对照人群的性别中存在差异。
