[Comparative studies of K1-67 expression between the primary tumor and breast cancer metastases to regional lymph nodes].

Breast cancer is often relatively slow growing, but at diagnosis about 40% of patients have regional spread to at least one axillary node. It has been shown that unrelated clones are in primary breast carcinomas. There is possibility that only a small subpopulation of the cells of the primary tumour (PT) metastasis. It has been shown that Ki-67 protein is a useful marker in histopathology, which is present during all active phases of the cell cycle and making possibility to assess growth fraction of tumour cells. The purpose of the study was to evaluate the expression of Ki-67 and comparison between the PTs and MRLNs as well as to estimate the relationships between Ki-67 and the chosen anatomoclinical features of the breast cancer. Immunohistochemical analyses for Ki-67 were performed on the PTs (69 cases without primary chemotherapy) and MRLNs (33 cases) of breast cancer. Increased expression of Ki-67 in PTs significantly correlated with pT2 stage of tumours (p < 0.05) and grade G3 (p < 0.04), but there was not relationship with lymph node status. Expression of Ki-67 positively correlated between PTs and MRLNs (p < 0.001). Comparison between PTs and matching MRLNs revealed that 23 (69.7%) cases showed a convergence between PTs and matching MRLNs with regard to negative or positive staining. We would like to emphasize the importance of studies concerning the proteins involved in proliferation in MRLNs, because knowledge about heterogeneity between PTs and MRLNs could shed light on tumour biology and may lead to development of more effective anti-cancer therapies.