Levels of 5-hydroxymethyl-2 '-deoxyuridine in DNA from blood of women scheduled for breast biopsy

Systemic oxidative stress is thought to contribute to risk of various cance rs, including breast cancer. DNA repair ability also has been associated wi th breast cancer risk. In this work, we examined levels of oxidative DNA da mage as an indication of breast cancer risk in women because oxidative DNA damage levels should reflect the net balance of oxidative stress and DNA re pair ability. Levels of 5-hydroxymethyl-2'-deoxyuridine, one form of oxidat ive DNA damage, were measured in DNA from blood of women scheduled for brea st biopsy. The blood samples analyzed included women whose biopsy results i ndicated invasive breast cancer, high-risk lesions (atypical hyperplasia or carcinoma in situ), or benign lesions, Mean levels of 5-hydroxymethyl-2'-d eoxyuridine were significantly higher in blood of women who had high risk o r invasive breast lesions versus women with benign lesions. If atypical hyp erplasia or carcinoma in situ are precursor lesions for breast cancer, then these results suggest that oxidative DNA damage may be involved in the can cer process before invasive cancer develops.