[Evaluation of Ki67 antigen using MIB1 antibody as a prognostic factor in renal pelvic and ureteral cancer].

(PURPOSE). Recently, several reports showed that immunohistochemistry using MIB-1 antibody, which recognizes Ki-67 antigen, is one of the useful methods to determine the proliferative activity in various cancer. To evaluate the prognostic usefulness of the MIB-1, antibody we assessed the cell proliferation immunohistochemically in urothelial cancer. (METHODS). The proliferative activity of thirty cases of renal pelvic and ureteral cancer has been investigated immunohistochemically using MIB-1 antibody, which recognizes Ki-67 antigen, a human nuclear antigen expressed in proliferating cells. (RESULTS). The Ki-67 index correlated with prognostic factors such as pathological stage and histological grade. The patients with early stage or low grade tumors had lower Ki-67 indices. And the Ki-67 index significantly correlated with recurrence and prognosis. The tumors of patients with recurrence or cancer death had higher Ki-67 indices. When the patients were suggrouped according to Ki-67 indices (more than 22%) had significantly worse prognosis even in the same grade. Especially in the grade 2 group, all the four patients in the higher Ki-67 index subgroup had recurred and died of cancer, whereas, in the subgrouped patients with tumors of lower Ki-67 indices, only three patients had bladder cancer recurrence, and no patients had died of cancer, except one case with advanced tumor (T4, N3, M0) resected incompletely. (CONCLUSIONS). These results indicate that the Ki-67 index is a useful prognostic factor and may enhance the prognostic accuracy determined by conventional morphological grading systems.