LEVELS OF 5-HYDROXYMETHYL-2'-DEOXYURIDINE IN DNA FROM BLOOD AS A MARKER OF BREAST-CANCER

BACKGROUND. Oxidative DNA damage can result from numerous endogenous m etabolic processes as well as from exposure to environmental and dieta ry oxidants. One important type of oxidative DNA damage is the formati on of hydroxylated DNA bases. This type of DNA damage may have a role in carcinogenesis. METHODS. We examined the levels of a hydroxylated t hy-nine residue, 5-hydroxy- methyl-2'-deoxyuridine, in DNA obtained fr om the peripheral blood of breast cancer patients and control women. T he isolated DNA was analyzed for levels of 5-hydroxymethyl-2'-deoxyuri dine by gas chromatography with mass spectral detection. RESULTS. The levels of this modified base were significantly higher in 25 breast ca ncer patients compared with 38 controls, with levels of 0.112 +/- 0.04 6 in the cancer patients versus 0.083 +/- 0.025 in the controls, given as pg 5-hydroxymethyl-2'-deoxyuridine/ng thymidine, mean +/- standard deviation (P = 0.019). After controlling for various covariates, the adjusted mean levels of oxidative DNA damage were still significantly higher in women with breast cancer relative to controls. CONCLUSIONS. These results indicate that the levels of 5-hydroxymethyl-2'-deoxyurid ine in DNA from peripheral nucleated blood may be potentially useful a s a marker of breast cancer. (C) 1996 American Cancer Society.