Correlation of proliferative activity with pathological features in breast carcinoma.

A presently undefined nuclear antigen recognized by the monoclonal antibody Ki-67, and the transferrin receptor (TR), both expressed by proliferating cells, were visualized in cryostat sections of 40 consecutive cases of primary breast cancer using a three-step immunoperoxidase technique. The percentages of Ki-67 and TR positive cells were determined. A strong positive correlation was observed between these two indices of proliferation (p less than 0.01). Moreover, each of them was positively related to the histological tumour grade (p less than 0.01), although the scatter in the number of proliferating cells within each grade was large. No significant relation (p greater than 0.05) was found between the percentages of Ki-67 and TR positive cells and tumor size and between these values and axillary node status. These correlations are similar to those recently reported in the relevant literature and suggest that immunohistochemical assessment of proliferative activity may prove to be an objective indicator of biological behaviour and therefore be of clinical and therapeutical importance.