Environmental cadmium and lead exposure and prostate-specific antigen among US men

Background Cadmium (Cd) and lead (Pb) are environmental pollutants acting as endocrine disruptors that may alter hormonal-related cancer risks. This study examined the association between blood Cd and Pb and prostate-specific antigen (PSA), a biomarker for prostate cancer detection. Methods Using data from 2007-2010 National Health and Nutrition Examination Survey, men aged 40 years and older with serum PSA and blood Cd and Pb measures were studied (n=2,189). Total PSA level (tPSA) and percent free/total PSA ratio (%fPSA) were outcomes of interest. The alternative cutpoints were used to categorize higher risks of prostate cancer (tPSA ≥10 and ≥4 ng/ml; %fPSA ≤ 25%). Blood concentration of Cd and Pb (μg/L) was defined as quintiles. Multivariate logistic regression was applied to estimate odds ratios (OR) and 95% confidence interval (CI). Results Adjusting for potential confounders, higher Pb concentrations was associated with increased odds of having higher tPSA (≥10 ng/ml, OR associated with fifth to first quintile = 7.95, 95% CI=1.46-43.18, p for trend=0.024) and lower %fPSA (≤25%, OR [fifth vs. first quintile] = 1.64, 95% CI=1.14-2.35, p for trend <0.001). Such association was not seen between Cd and tPSA or %fPSA. However, men with higher Cd concentration (≥2 µg/L) had increased odds of having lower %fPSA (≤25%) compared to those with lower Cd in blood (OR=2.71, 95% CI=1.35-5.46). Conclusion Cd and Pb in blood were associated with PSA biomarkers in the US population. Further studies are necessary to investigate potential mechanisms of the finding. Monitoring environmental exposure to such pollutants may be helpful on prostate cancer prevention.