Evaluation of immunohistochemical staining of breast tissue by an oestrogen-regulated protein, 24K according to epidemiological and radiological breast cancer risk criteria.

The staining characteristics of monoclonal antibodies (MAb) are often determined on small numbers of biopsies. The true staining profile can only properly be determined when large numbers of biopsies are stained. We have examined the staining profile of 24K MAb on 146 benign breast biopsies. The staining characteristics were then grouped according to whether the patients were at high or low risk of breast cancer by current epidemiological or radiological risk criteria. This was done to detect whether 24K MAb could be used as a marker of cancer risk. Only Wolfe coded risk criteria showed staining differences between the two risk categories. Cytoplasmic staining was more common in the low risk Wolfe coded groups (P = 0.03, Fisher's exact test). We recommend that further studies be undertaken to evaluate the role of 24K MAb as a marker of cancer risk.