. 2019 Jan 4;188(4):34–43. doi: 10.1093/aje/kwaa035

Table 3.

Modification by Selenium: Association Between Each Metal and Breast Cancer Within Categories of Selenium (Time-Corrected Metal Levels) (n = 1,217 Sister Pairs), Sister Study (2003–2009) and Two Sister Study (2008–2010), United States

Trace Element^a	Overall		Selenium Level ≤ 0.941 μg/g^b		Selenium Level > 0.941 μg/g^b		P Value for Heterogeneity by Selenium Level
Trace Element^a	OR^c	95% CI	OR	95% CI	OR	95% CI	P Value for Heterogeneity by Selenium Level
Arsenic	1.27	0.95, 1.70	1.24	0.91, 1.69	1.31	0.91, 1.89	0.75
Cadmium	0.90	0.67, 1.21	0.95	0.69, 1.30	0.85	0.59, 1.23	0.54
Cobalt	1.15	0.88, 1.52	1.15	0.78, 1.70	1.15	0.88, 1.52	1.00
Chromium	1.09	0.84, 1.42	1.03	0.77, 1.39	1.16	0.84, 1.59	0.53
Copper	1.22	0.89, 1.68	1.02	0.71, 1.46	1.49	1.05, 2.13	0.04
Mercury	1.07	0.77, 1.48	0.95	0.64, 1.41	1.19	0.84, 1.68	0.21
Molybdenum	1.16	0.83, 1.61	1.19	0.84, 1.67	1.12	0.75, 1.68	0.76
Lead	1.09	0.83, 1.44	1.15	0.81, 1.64	1.04	0.77, 1.39	0.55
Tin	1.21	0.90, 1.63	1.19	0.83, 1.72	1.23	0.89, 1.71	0.87
Vanadium	1.36	0.85, 2.17	1.43	0.86, 2.37	1.29	0.79, 2.12	0.58

Abbreviations: CI, confidence interval; OR, odds ratio.

^a Time-corrected trace element levels. All models were adjusted for age and educational level. Data are shown for those with element levels greater than the median (0.944 μg/g); the reference group were those with element levels less than or equal to the median.

^b The median value was 0.944 μg/g.

^c Adjusted for selenium.