Higher serum zinc levels may reduce the risk of cervical cancer in Asian women: A meta-analysis

Objective This meta-analysis was conducted to examine the possible association between serum zinc concentration and cervical cancer risk. Methods PubMed, WanFang, China National Knowledge Infrastructure, and SinoMed databases were searched for relevant articles published between January 1980 and September 2017. Results were combined using a random-effects model, and pooled standardized mean differences (SMD) and 95% confidence intervals (CI) were calculated to compare serum zinc levels in patients with cervical cancer versus controls. Publication bias was evaluated using Begg's funnel plot and Egger's regression asymmetry test. Results Twelve articles regarding serum zinc levels and cervical cancer were included in this meta-analysis. Combined results showed that serum zinc levels in cervical cancer cases were significantly lower than in controls without cervical cancer (summary SMD -1.379, 95% CI -1.527, -1.231), with high heterogeneity (I-2 = 98.8%). Analysis of data stratified by geographic location showed a significant association between serum zinc levels and cervical cancer risk in Asian populations (summary SMD -1.391, 95% CI -1.543, -1.239). Conclusions Higher serum zinc levels may be a protective factor for cervical cancer in Asian women.