Arsenic not a risk factor for prostate cancer

Arsenic exposure in drinking water, even at high levels, does not appear to contribute to an increased risk of prostate cancer, according to a case–control study.

The study was conducted in Northern Chile where the range of exposure to arsenic was wide, between <10 and 860 µg/L. Researchers identified prostate cancer cases from cancer committees, hospitals, and medical facilities in the area. They also established a control cohort using the Chile Voter Registry, which included >90 percent of adults ages >50 years.

A total of 343 men with prostate cancer ages ≥40 years and 337 age-matched controls without prostate cancer were included in the analysis. Overall, 23 percent of men were exposed to arsenic concentrations >800 µg/L in their lifetime, which is 80 times the recommended thresholds. Cases and controls were demographically similar.

In regression models adjusted for age and smoking status, men in the highest vs lowest quartile of lifetime cumulative and average arsenic concentrations in drinking water had a 14-percent and 17-percent greater odds of prostate cancer, respectively (odds ratio [OR], 1.14, 95 percent confidence interval [CI], 0.71–1.84 and OR, 1.17, 95 percent CI, 0.73–1.89).

The findings suggest that arsenic exposure in drinking water, even at high levels, does not promote prostate cancer, according to the researchers.