Elevated polycyclic aromatic hydrocarbonDNA adducts in benign prostate and risk of prostate cancer in African Americans

CarcinogenDNA adducts, a marker of DNA damage, are capable of inducing mutations in oncogenes and tumor suppressor genes, resulting in carcinogenesis. We have shown previously that polycyclic aromatic hydrocarbon (PAH)DNA adduct levels in prostate cancer cases vary by cellular histology and that higher adduct levels are associated with biochemical recurrence. A nested casecontrol study was conducted in a historical cohort of 6692 men with histopathologically benign prostate specimens. PAH-DNA adduct levels were determined by immunohistochemistry in benign prostate specimens from 536 prostate cancer case-control pairs (59% White and 41% African American). We estimated the overall and race-stratified risk of subsequent prostate cancer associated with higher adduct levels. Prostate cancer risk for men with elevated adduct levels (defined as greater than control group median) was slightly increased [odds ratio (OR) 1.28, 95% confidence interval (CI) 0.981.67, P 0.07]. After race stratification, elevated adduct levels were significantly associated with increased risk in African American men (OR 1.56, CI 1.002.44, *P 0.05) but not White men (OR 1.14, CI 0.821.59, P 0.45). Elevated PAH-DNA adduct levels were significantly associated with 60% increased risk of prostate cancer among cases diagnosed 14 years after cohort entry (OR 1.60, CI 1.072.41) with a greater risk observed in African Americans within the first 4 years of follow-up (OR 4.71, CI 1.9711.26, ***P 0.0005). Analyses stratified by age or tumor grade revealed no additional significant heterogeneity in risk. Increased prostate cancer risk associated with high PAH-DNA adduct levels in benign prostate was found only in African Americans; risk was greatest within 4 years of follow-up, possibly reflecting a carcinogenic process not yet histologically detectable.