8-HYDROXYDEOXYGUANOSINE LEVELS IN DNA OF HUMAN BREAST CANCERS ARE NOT SIGNIFICANTLY DIFFERENT FROM THOSE OF NON-CANCEROUS BREAST TISSUES BY THE HPLC-ECD METHOD

8-Hydroxydeoxyguanosine (oh(8)dG) is a promutagenic DNA lesion produced by oxygen radicals, and a high level of 8-hydroxyguanine in breast cancers was previously demonstrated by the gas chromatography-mass-spectrometry method, To confirm the previous observation, the oh(8)dG levels of DNA of 22 breast cancers and corresponding adjacent non-cancerous breast tissues were analyzed by high performance liquid chromatography-electrochemical detector (HPLC-ECD) system, and the correlation of the oh(8)dG levels in breast cancer DNAs with clinical and immunohistochemical parameters was examined. However, the levels of oh(8)dG in DNA of breast cancers are not significantly different from those of corresponding non-cancerous breast tissues (P=0.084) by the HPLC-ECD method. Furthermore, the oh(8)dG levels in breast cancers were not associated with p53 and erbB-2 immunoreactions, with expression of estrogen and progesterone receptors, and with clinical stage and histological grade. Thus, in contrast to the previous data, the present study using the HPLC-ECD method does not indicate an increase of oh(8)dG levels in breast cancers.