Departamento de Genética, Facultad de Medicina, Benemérita Universidad Autónoma de Puebla, 13 Sur 2901 Col. Volcanes, C.P. 72420, Puebla, Pue, Mexico.
Laboratorio de Investigación en Fisiopatología de Enfermedades Crónicas, Centro de Investigación Biomédica de Oriente, IMSS, Km 4.5 Carretera Federal Atlixco-Metepec, C.P. 42730, Atlixco, Puebla, Mexico.
Breast Cancer. 2019 Sep;26(5):602-611. doi: 10.1007/s12282-019-00961-8. Epub 2019 Mar 15.
Previous meta-analyses have shown an ethnic dependency of the C677T and the A1298C methylenetetrahydrofolate reductase (MTHFR) polymorphisms, with no focus on the Latino population. For Latinos, many studies have examined these polymorphisms and breast cancer susceptibility, yielding no concise result. Therefore, we undertook this meta-analysis to determine the effect these polymorphisms have on breast cancer risk for Latinos.
PubMed, EBSCO, LILACS, Scopus, and Latin American-specific databases were searched for studies exploring the association between the MTHFR polymorphisms and breast cancer susceptibility in Latinos until January 2019. Genotype distributions were extracted and, depending on the level heterogeneity determined by the ψ-based Q test and the I test, fixed-effects or random-effects models were used to calculate pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) for the heterozygous, homozygous, dominant, recessive, and allelic genetic models. No publication bias was detected by the Begg-Mazumdar's test and Egger's test.
Of the 280 retrieved publications, 9 studies were included: 9 for the C677T polymorphism and 5 for the A1298C polymorphism. For the C677T polymorphism, there was an elevated risk for the homozygous (OR 1.42, 95% CI 1.05-1.92), the dominant (OR 1.16, 95% CI 1.02-1.31), the recessive (OR 1.33, 95% CI 1.01-1.75), and the allelic model (OR 1.17, 95% CI 1.03-1.33, p < 0.01). No association between the A1298C polymorphism and the risk to develop breast cancer was determined.
The results indicated that, for Latinos, the C677T polymorphism is associated with a significant risk for developing breast cancer, whereas the A1289C polymorphism does not.
先前的荟萃分析表明，C677T 和亚甲基四氢叶酸还原酶（MTHFR）A1298C 多态性存在种族依赖性，但是并没有关注拉丁人群体。对于拉丁人群体，许多研究已经检验了这些多态性与乳腺癌易感性之间的关系，但是没有得出明确的结果。因此，我们进行了这项荟萃分析，以确定这些多态性对拉丁裔人群患乳腺癌的风险的影响。
检索了 PubMed、EBSCO、LILACS、Scopus 和拉丁美洲特定数据库，以寻找研究拉丁裔人群中亚甲基四氢叶酸还原酶多态性与乳腺癌易感性之间关系的研究，检索时间截至 2019 年 1 月。提取基因型分布，并根据 ψ 基于 Q 检验和 I 检验确定的水平异质性，使用固定效应或随机效应模型计算杂合子、纯合子、显性、隐性和等位基因遗传模型的合并优势比（OR）及其 95%置信区间（95%CI）。未通过 Begg-Mazumdar 检验和 Egger 检验检测到发表偏倚。
在检索到的 280 篇文献中，有 9 项研究被纳入：9 项研究涉及 C677T 多态性，5 项研究涉及 A1298C 多态性。对于 C677T 多态性，纯合子（OR 1.42，95%CI 1.05-1.92）、显性（OR 1.16，95%CI 1.02-1.31）、隐性（OR 1.33，95%CI 1.01-1.75）和等位基因模型（OR 1.17，95%CI 1.03-1.33，p<0.01）的风险均升高。未确定 A1298C 多态性与患乳腺癌风险之间的关系。
结果表明，对于拉丁裔人群，C677T 多态性与患乳腺癌的风险显著相关，而 A1289C 多态性则没有。
