The relationship between genetic damage from polycyclic aromatic hydrocarbons in breast tissue and breast cancer

A number of polycyclic aromatic hydrocarbons (PAH) are widespread environme ntal contaminants that cause mammary cancer experimentally. We investigated whether exposure and susceptibility to PAH, as measured by PAH-DNA adducts in breast tissue, are associated with human breast cancer. We carried out a hospital-based case-control study using immunohistochemical methods to an alyze PAH-DNA adducts in tumor and nontumor breast tissue from cases and be nign breast tissue from controls. The subjects were white, African-American and Latina women without prior cancer or treatment, including 119 women wi th breast cancer and 108 with benign breast disease without atypia, PAN-DNA adducts measured in breast tumor tissue of 100 cases and in normal tissue from 105 controls were significantly associated with breast cancer (OR = 4. 43, 96% CI 1.09-18.01) after controlling for known breast cancer risk facto rs and current active and passive smoking, and dietary PAH, There was subst antial interindividual (17-fold) variability in adducts overall, with 27% o f cases and 13% of controls having elevated adducts, The odds ratio for ele vated adducts in tumor tissue compared with control tissue was 2.56 (1.05-6 .24), after controlling for potential confounders. Adduct levels in tumor t issue did not vary by stage or tumor size. Among 86 cases with paired tumor and nontumor tissue, adducts levels in these two tissues were highly corre lated (r = 0.56, P<0.001). However, the corresponding associations between case-control status and adducts measured in nontumor tissue from 90 cases a nd in normal tissue from 105 controls were positive but not statistically s ignificant. Overall, neither active nor passive smoking, or dietary PAH wer e significantly associated with PAH-DNA adducts or breast cancer case-contr ol status. These results suggest that genetic damage reflecting Individual exposure and susceptibility to PAH may play a role in breast cancer; but mo re research is needed to determine whether the findings are relevant to cau sation or progression of breast cancer.