Departments of Epidemiology and Preventive Medicine, Gifu University Graduate School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan.
Breast Cancer Res Treat. 2013 Feb;138(1):235-9. doi: 10.1007/s10549-013-2414-4. Epub 2013 Jan 29.
Non-occupational exposure to cadmium has been suspected to be a risk factor for breast cancer. The present study examined the association between urinary cadmium level and the risk of breast cancer in a case-control study among Japanese women. Cases were 153 women newly diagnosed and histologically confirmed with breast cancer at a general hospital in Gifu, Japan. A total of 431 controls individually matched to cases by age, menopausal status, and the period of urine sampling were selected from those who attended a breast cancer mass screening at this hospital. Urinary cadmium levels were measured using spot urine samples. Spot urine samples were collected from cases after surgery but before any cancer therapy. For controls, spot urine samples were obtained at the date of the screening visit. Information on known or suggested breast cancer risk factors was obtained by a self-administered questionnaire. The odds ratios (ORs) and 95 % confidence intervals (CIs) of breast cancer according to the tertile of the creatinine-adjusted cadmium level were calculated using conditional logistic regression models. Women in the highest tertile of the creatinine-adjusted cadmium level (>2.620 μg/g) had significantly elevated OR of breast cancer relative to those in the lowest tertile (<1.674 μg/g) after controlling for covariates [OR = 6.05, (95 % CI 2.90, 12.62)]. The trend of increase in risk with increasing cadmium level was also statistically significant [OR = 1.67, (95 % CI 1.39, 2.01) for every 1.0 μg/g increase in urinary cadmium level, P-trend <0.01]. These data suggested that exposure to cadmium was associated with a risk of breast cancer in Japanese women.
非职业性镉暴露已被怀疑是乳腺癌的一个危险因素。本研究在日本岐阜县一家综合医院对新诊断为乳腺癌并经组织学证实的 153 名女性进行了病例对照研究，以探讨尿镉水平与乳腺癌风险之间的关系。共选择了 431 名与病例按年龄、绝经状态和尿样采集期相匹配的对照，这些对照来自于该医院参加乳腺癌大规模筛查的人群。使用随机尿样测量尿镉水平。病例组在手术后但在任何癌症治疗之前采集随机尿样。对于对照组，在筛查就诊当天采集随机尿样。通过自我管理问卷获取已知或疑似乳腺癌危险因素的信息。使用条件逻辑回归模型计算按肌酐校正的镉水平三分位数的乳腺癌比值比（OR）和 95%置信区间（CI）。在校正了肌酐调整后的镉水平的三分位数后，最高三分位（>2.620μg/g）的女性与最低三分位（<1.674μg/g）相比，乳腺癌的 OR 显著升高[OR=6.05，（95%CI 2.90，12.62)]。随着镉水平的升高，风险增加的趋势也具有统计学意义[OR=1.67，（95%CI 1.39，2.01），每增加 1.0μg/g 尿镉水平，P-趋势<0.01]。这些数据表明，日本女性的镉暴露与乳腺癌风险相关。
