Thus far, Dr. Petrakis said, he had found that in women with […] extractable breast fluid, the amount of lipid peroxides in the fluid was on the average seven times higher in Caucasian women than in women of Chinese de[s]cent. In addition, women with cystic breast disease, who face a higher than usual risk of breast cancer, appear to have more peroxides in their breast fluid than women with normal breasts.
Source: wiktionary