血清半胱氨酸与肿瘤相关性meta分析

Relationship between plasma cysteine and cancer risk:a meta-analysis

目的:半胱氨酸是一碳单位代谢过程的关键组分,在甲基化过程中发挥着重要作用。许多流行病学研究评估了半胱氨酸与肿瘤风险之间的相关性,但结果不一致。本荟萃分析的目的是评估血清半胱氨酸与肿瘤风险之间的关联。方法:检索PubMed和EMBASE数据库,收集2017年11月之前国内外发表的关于血清中半胱氨酸含量与肿瘤风险关系的研究,共有8篇文章符合纳入标准。使用相对危险度(relative risk,RR)及其相应的95%CI来评估半胱氨酸与肿瘤风险关系的强度。结果:高水平的血清半胱氨酸可以降低肿瘤风险(RR:0.72,95%CI:0.62～0.83),未观察到显著异质性(P=0.052,I2=45.1%),剂量效应分析显示当血清半胱氨酸浓度大于275μmol/L时,半胱氨酸水平越高,其发生癌症的风险越低。结论:本研究结果表明较高的半胱氨酸水平可能会降低患癌症的风险。

Objective:Cysteine,a key component in the one-carbon metabolism,is of great importance in methylation. Many epidemiologic studies have assessed the association between cysteine and risk of cancer,but results are inconsistent. The objective of our meta-analysis is was to assess the association between plasma cysteine and cancer risk. Methods:Comprehensive searches were performed on PubMed and Embase databases up to November 1,2017 to identify relevant studies. Eight separate studies containing 11 comparisons were included in the meta-analysis. Relative risk(RR)and their corresponding 95% confidence intervals(95% CIs)were used to estimate the strength of relationship between cysteine and cancer risk. Results:The pooled RR of cancer risk for the highest versus lowest categories of blood cysteine level was 0.72(95%CI:0.62~0.83)with no significant heterogeneity observed(P=0.052,I2=45.1%). Dose-response analysis showed that when plasma cysteine concentration was higher than 275 μmol/L,the higher cysteine level,the lower risk of cancer. Conclusion:Generally,our results indicated that higher concenteation of cysteine may decrease the risk of cancer.