Background: Cadmium (Cd) is a toxic metal classified as a human carcinogen by the International Agency for Research on Cancer.
Objective: We evaluated the association of long-term Cd exposure, as measured in urine, with cancer mortality in American Indians from Arizona, Oklahoma, and North and South Dakota who participated in the Strong Heart Study during 1989–1991.
Methods: The Strong Heart Study was a prospective cohort study of 3,792 men and women 45–74 years of age who were followed for up to 20 years. Baseline urinary Cd (U-Cd) was measured using inductively coupled plasma mass spectrometry. We assessed cancer events by annual mortality surveillance.
Results: The median (interquintile range) U-Cd concentration was 0.93 (0.55, 1.63) μg/g creatinine. After adjusting for sex, age, smoking status, cigarette pack-years, and body mass index, the adjusted hazard ratios (HRs) comparing the 80th versus the 20th percentiles of U-Cd were 1.30 (95% CI: 1.09, 1.55) for total cancer, 2.27 (95% CI: 1.58, 3.27) for lung cancer, and 2.40 (95% CI: 1.39, 4.17) for pancreatic cancer mortality. For all smoking-related cancers combined, the corresponding HR was 1.56 (95% CI: 1.24, 1.96). Cd was not significantly associated with liver, esophagus and stomach, colon and rectum, breast, prostate, kidney, or lymphatic and hematopoietic cancer mortality. On the basis of mediation analysis, we estimated that the percentage of lung cancer deaths due to tobacco smoking that could be attributed to Cd exposure was 9.0% (95% CI: 2.8, 21.8).
Conclusions: Low-to-moderate Cd exposure was prospectively associated with total cancer mortality and with mortality from cancers of the lung and pancreas. The implementation of population-based preventive measures to decrease Cd exposure could contribute to reducing the burden of cancer.
1Department of Environmental Health Science, and 2Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA; 3Environmental Epidemiology and Cancer Unit, National Center for Epidemiology, Carlos III Institute of Health, Madrid, Spain; 4Consortium for Biomedical Research in Epidemiology & Public Health (CIBER en Epidemiología y Salud Pública–CIBERESP), Madrid, Spain; 5Fundacion de Investigacion del Hospital Clinico de Valencia-INCLIVA, Valencia, Spain; 6Institute of Chemistry, Analytical Chemistry, Karl-Franzens University, Graz, Austria; 7Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA; 8Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA; 9MedStar Health Research Institute, Hyattsville, Maryland, USA; 10Georgetown-Howard Universities Center for Clinical and Translational Science, Washington, DC, USA; 11Center for American Indian Health Research, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA; 12Missouri Breaks Industries Research Inc., Timber Lake, South Dakota, USA; 13Department of Oncology, Johns Hopkins Medical Institutions, Baltimore, Maryland, USA
Recommended Citation:
Esther García-Esquinas,1,2,et al. Cadmium Exposure and Cancer Mortality in a Prospective Cohort: The Strong Heart Study[J]. Environmental Health Perspectives,2014-01-01,Volume 122(Issue 4):363