School of Public Health, Guangzhou Medical University, Guangzhou 510182, People's Republic of China; Longgang Central Hospital of Shenzhen, Shenzhen 518116, People's Republic of China.
School of Public Health, Guangzhou Medical University, Guangzhou 510182, People's Republic of China.
Cancer Epidemiol. 2016 Jun;42:101-7. doi: 10.1016/j.canep.2016.04.002. Epub 2016 Apr 14.
Cadmium, a human carcinogenic heavy metal, has been reported to be associated with breast cancer risk; however, the results from the epidemiological studies are not always consistent. The objective of this study was to quantitatively summarize the current evidence for the relationship between cadmium exposure and breast cancer risk using meta-analysis methods. Six studies determining the dietary cadmium intake level and five studies evaluating the urinary cadmium level were identified in a systematic search of MEDLINE and PubMed databases, and the associations between these levels and breast cancer risk were analysed. The pooled estimates under the random-effects model suggested that higher urinary cadmium levels were associated with an increased risk for breast cancer (highest versus lowest quantile, pooled odds ratio [OR]=2.24, 95% confidence interval [95%CI]=1.49-3.35) and a 1μg/g creatinine increase in urinary cadmium led to a 1.02-fold increment of breast cancer (pooled OR=2.02, 95%CI=1.34-3.03); however, pooled estimates for dietary cadmium intake found no significant association between cadmium exposure and breast cancer risk (highest versus lowest quantile, pooled relative risk [RR]=1.01, 95%CI=0.89-1.15). These results suggest that cadmium exposure may lead to an increased risk of breast cancer, and urinary cadmium levels can serve as a reliable biomarker for long-term cadmium exposure and may predict the breast cancer risk.
镉是一种对人体有致癌作用的重金属，据报道与乳腺癌风险相关；然而，流行病学研究的结果并不总是一致的。本研究的目的是通过荟萃分析方法定量总结镉暴露与乳腺癌风险之间关系的现有证据。通过对 MEDLINE 和 PubMed 数据库的系统检索，确定了 6 项研究来确定膳食镉摄入量水平，5 项研究评估了尿镉水平，分析了这些水平与乳腺癌风险之间的关系。随机效应模型下的汇总估计表明，较高的尿镉水平与乳腺癌风险增加相关（最高与最低四分位数相比，汇总优势比 [OR]=2.24，95%置信区间 [95%CI]=1.49-3.35），尿镉每增加 1μg/g 肌酐，乳腺癌的风险增加 1.02 倍（汇总 OR=2.02，95%CI=1.34-3.03）；然而，膳食镉摄入量的汇总估计表明，镉暴露与乳腺癌风险之间没有显著关联（最高与最低四分位数相比，汇总相对风险 [RR]=1.01，95%CI=0.89-1.15）。这些结果表明，镉暴露可能导致乳腺癌风险增加，尿镉水平可以作为长期镉暴露的可靠生物标志物，并可能预测乳腺癌风险。
