ABSTRACT Epidemiologic studies have indicated that n-3 polyunsaturated fatty acids (PUFAs) supplementation may reduce the incidence of breast cancer, also in vivo and in vitro studies have shown that n-3 PUFAs have an inhibitory effect on breast cancer cells. One important n-3 PUFA are eiocosapentaenoic acid (EPA), which are metabolized to five regioisomeric epoxyeicosatetraenoic acids (epoxy-EPAs) ...