Association of urinary cesium with breast cancer risk

The aim of this study is to examine the association of urinary cesium with breast cancer risk.

We collected survey data and urine specimens from 240 women with incident invasive breast cancer before their treatment and 246 age-matched female controls between October 2009 and July 2010. Urinary concentrations of cesium were determined by inductively coupled plasma mass spectrometry. Interviews were conducted by face-to-face to obtain information on potential breast cancer risk factors. Logistic regression analysis was used to estimate the associations.

Creatinine-adjusted levels [median (25th, 75th) ug/g] of cesium in cases and controls were 17.6 (13.1, 24.0) and 19.3 (15.3, 25.7), respectively. After adjustment for potential risk factors, women in the second and highest tertile of cesium showed a decreased risk of breast cancer in a dose-dependent manner as compared with those in the lowest tertile [ORs and 95% CIs: 0.75 (0.46- 1.22) and 0.50 (0.30-0.82), respectively]. This decrease was more evident in women with ER positive or localized clinical stage in an exploratory stratification analysis.

These findings suggest that cesium may have anticancer efficacy and urinary cesium has potential as a biomarker for breast cancer risk assessment.