Increased Lead Exposure May Raise Kidney Cancer Risk

Higher blood lead levels are associated with an elevated risk of renal cell carcinoma (RCC), according to a study.

The study, led by Robin Taylor Wilson, PhD, of Pennsylvania State University College of Medicine in Hershey, included 154 individuals with a new diagnosis of RCC and 308 matched controls. The subjects were male Finnish smokers participating in the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study. The mean follow-up time was 12.1 years for cases and 18.1 years for controls.

Compared with subjects in the first quartile of blood lead level (below 2.50 µg/dL), those in the fourth quartile (4.66 µg/dL and higher) had a twofold increased risk of RCC after adjusting for confounders, the researchers reported in Cancer Epidemiology, Biomarkers & Prevention (published online ahead of print).

Higher total serum calcium was associated with a significantly reduced risk of RCC. Compared with subjects in the first quartile of serum calcium (below 9.50 mg/dL), those in the fourth quartile (10.30 mg/dL or higher) had a 70% decreased risk.

In addition, the study showed that among cases alone, lower baseline serum calcium was significantly associated with a shorter time to RCC diagnosis after study enrollment, after adjusting for other RCC risk factors, such as age at randomization, pack-years of smoking, body mass index, and systolic blood pressure.

Mean total serum calcium levels were 9.5, 9.7, 9.8, and 9.9 mg/dL in those diagnosed from 5.0-8.9, 9.0-11.7, 11.8-15.1, and 15.2-20.9 years after study enrollment, respectively. The researchers observed a similar but nonsignificant trend with serum 25-hydroxyvitamin D levels.