The proliferation behavior of bone tumors investigated with the monoclonal antibody Ki-67.

Specimens of several tumor entities at various grades of malignancy were selected from the Bone Tumor Registry of Westphalia for an immunohistological study of their proliferation behavior. Using the monoclonal antibody Ki-67 directed against a nuclear antigen present in all active phases of the cell cycle (G1, S, G2, and M), we were able to demonstrate the growth fractions in tissues with an atypical rate of proliferation, implying an increased risk of malignant transformation. In the 97 cases examined we found a good correlation of the biological proliferation behavior with the expression of the nuclear antigen Ki-67. Moreover, our immunohistological results are comparable with the data from the same tumor entities obtained by other methods such as flow cytometry and autoradiography. Thus the monoclonal antibody Ki-67 provides an excellent marker for labeling the growth fraction in a human tissue. Its practical impact lies in the differential diagnostic analysis of the proliferation rate in a given tumor and its possible grading, and in pre- or posttherapeutic monitoring of patients and the establishment of a prognosis.