Background: For a variety of human malignancies, static DNA cytophotometry and immunostaining for the Ki-67 antigen using the antibody MIB-1 have provided significant prognostic information.
Methods: Surgical specimens of 58 renal cell carcinomas (RCCs) were investigated by conventional histology, DNA cytophotometry, and MIB-1 immunostaining.
Results: The MIB-1 indices and DNA data were found not only to be significantly correlated with various other morphologic parameters, but also to the clinical behavior of RCC. In the course of this study (median observation period: 31 months), 27% of patients died from RCC. None of these patients belonged to the group of 37 patients with RCCs exhibiting diploid or euploid DNA histograms. Lethal outcome occurred in only 16 of the 21 patients (76%) with noneuploid or aneuploid histogram tumors (P < 0.0001). According to their MIB-1 indices and upon choosing different cutoff levels, the 58 RCCs were categorized into 2 groups with either low or high proliferative activity. Using the median and the mean MIB-1 index as cutoffs, none of the patients with tumors showing low proliferative activity had died, whereas 16 of 29 patients (55%) or, respectively, 16 of 25 patients (64%) with tumors exhibiting high proliferative activity, had died from RCC (P < 0.0001).
Conclusions: In addition to tumor grade and stage, both a high MIB-1 index and a noneuploid or aneuploid DNA histogram of a given RCC have the potential to identify tumor patients with an impaired prognosis.