[Immunohistochemical study of breast neoplasms cells using different markers of proliferation]

Proliferative activity was studied in 58 breast tumors: 10 benign tumors and 48 carcinomas 41 of which were invasive ductal carcinomas. Combined use of 3 proliferation markers (5-bromo-2-deoxyuridine, nuclear antigen of proliferating cells and Ki-67 antigen) which reflect different phases of mitotic cycle, enable determination of the S-phase index and estimation of the tumor proliferative pool as well as percentage of cells in S-phase and in mitosis and, respectively, relative duration of these phases. In breast carcinoma, S-phase is the longest phase of the mitotic cycle (45% of its duration), mitosis takes 5%. Proliferation indices when all three markers were used carry high positive correlation (r = 0.73-0.94; p < 0.000001). Proliferative activity of breast carcinoma is 5 times higher than in benign tumors and significantly increases in recurrent tumors and with growing histological malignancy of the tumor. A positive correlation exists between proliferative activity of the primary carcinoma and that of metastatic tumor in regional lymph nodes but proliferation in metastasis is, as a rule, less active than in the primary tumors. Antigen Ki-67 is the most optimal among the above proliferation markers because its expression reflects the tumor proliferative pool and its use does not require additional procedures and calculation of proliferating cells is simple and reliable.