Tumor proliferation is inversely associated with survival in patients with transitional cell carcinoma of urinary bladder. Ki67 and MIBI monoclonal antibodies directed against different epitopes of the same proliferation-related antigen. Whereas
Ki67
works only on frozen section, MIBI may be used also on fixed sections. In order to determine whether MIBI is clinically a useful proliferation marker as well as prognostic one or not, MIBI expression in bladder cancers were compared with
conventional
prognostic parameters such as Ash histologic grade, and proliferation index including S-phase fraction calculated by flow cytometry.
The expression of MIBI was assessed immunohistochemically in 36 cases of transitional cell carcinoma with anti-MIBI monoclonal antibody which can recognize a formalin resistent epitope of Ki167 in formalin-fixed, paraffin wax embedded sections
after
incubation in a microwave oven. Then, image analysis was employed for quantitation of immunostained MIBI expression. MIBI expression rates were highly correlated with Ash histologic grade. And, two parameters revealed a good correlation in linear
regression analysis(Y=4.16X-3.01). Also, proliferation index and S-phase fraction calculated by flow cytometry were highly correlated with MIBI expression(r=0.92, r=0.87, respectively) therefore, MIBI immunostaining is considered as a useful
prognostic
marker in transitional cell carcinoma of urinary bladder and a reasonable substitute for the Ki67 monoclonal antibody. In addition, the advantages of MIBI immunostaining on paraffin sections include the feasibility of retrospective studies and of
obtaining clear morphologic specimens that are optimal for use with computer-assisted image analysis systems.
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