Immunohistochemical Characterization of Antioxidant Enzymes in Human Breast Cancer

Intrinsic antioxidant enzymes (AE) are essential for protection against potential cellular damage by free radicals (FRs), which affect a variety of biological processes. The levels or activities of AEs can be abnormal in human malignancies in general, and FR production is a possible mechanism of estrogen related carcinogenesis specifically. However, the role of AEs in breast cancer ramains unclear. Immunodetectable AEs were characterized in 95 node negative cancers using rabbit polyclonal antibodies. Results were correlated with established and experimental biomarkers of breast cancer. AEs were greater than benign differentiated epithelium in more than 40% and lower in 10-14% of tumors. Patterns of staining were enzyme and tumor pattern specific. Increased immunodetectable AE was associated with large, poorly differentiated tumors, and younger age. Catalase correlated with nuclear grade and disease related death (p< 0.05), and highlighted tumor microvasculature. Additional work in this area may further elucidate the role of AEs in breast cancer growth and progression.