This systematic review and meta-analysis were conducted to investigate the association between methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms with breast cancer (BC) in Asians. Systematic searches were conducted in PubMed, EMBASE, Web of Science, and Scopus by May 2020. Inter-study heterogeneity was also assessed with a Q test, along with I² statistics. Random-effects models were applied to pooled crude ORs with corresponding 95% CIs for the genetic models. A total of 1097 identified results, along with 36 qualified studies were included: for MTHFR C677T polymorphism, a total of 36 studies was comprised of 11,261 cases and 13,318 controls and for MTHFR A1298C polymorphism, a number of 19 studies contained 7424 cases and 8204 controls. Likewise, for C677T polymorphism, an increased risk of BC was seen for the allelic (OR 1.21, 95% CI 1.09–1.33, P < 0.01, I² = 78.9%), dominant (OR 1.17, 95% CI 1.05–1.30, P < 0.01, I² = 71.8%), recessive (OR 1.43, 95% CI 1.23–1.67, P < 0.01, I² = 55.8%), and homozygous models (OR 1.48, 95% CI 1.25–1.75, P < 0.01, I² 59.9%) among BC patients compared to controls. Also, in terms of A1298C polymorphism, an association was found between the allelic (OR 1.15, 95% CI 1.04–1.28, P < 0.01, I² 70.4%) and homozygous models (OR 1.38, 95% CI 1.15–1.66, P < 0.01, I² 44.2%) with the risk of BC. In conclusion, findings revealed that MTHFR C677T variant might be a factor that predisposes BC in Asians. Furthermore, it was found that A1298C variant acts as a BC risk factor, particularly in a Western Asia population.

进行了系统的综述和荟萃分析，以研究亚甲基四氢叶酸还原酶（MTHFR）C677T与A1298C多态性与亚洲人乳腺癌（BC）的关联。到2020年5月，在PubMed，EMBASE，Web of Science和Scopus中进行了系统搜索。还使用Q检验和I ²评估了研究间异质性。统计。将随机效应模型应用于具有遗传模型的相应95％CI的汇总原油OR。总共鉴定了1097项结果，并进行了36项合格研究：对于MTHFR C677T多态性，总共36项研究包括11,261例病例和13,318例对照，对于MTHFR A1298C多态性，许多19项研究包括7424例病例和8204例对照。同样，对于C677T多态性，等位基因（OR 1.21，95％CI 1.09–1.33，P  <0.01，I ²  = 78.9％），显性（OR 1.17，95％CI 1.05-1.30，P  <0.01，I ²  = 71.8％），隐性（OR 1.43，95％CI 1.23–1.67，P  <0.01，I ²与对照相比，BC患者中的 纯合子模型（= 55.8％）和纯合模型（OR 1.48，95％CI 1.25-1.75，P  <0.01，I ² 59.9％）。此外，就A1298C多态性而言，在等位基因（OR 1.15，95％CI 1.04–1.28，P  <0.01，I ² 70.4％）和纯合模型（OR 1.38，95％CI 1.15–1.66，P  <0.01，I ² 44.2％），有BC风险。总之，研究结果表明，MTHFR C677T变异体可能是亚洲人中易患BC的因素。此外，发现A1298C变体是BC的危险因素，尤其是在西亚人群中。