APOPTOSIS IN RENAL-CELL CARCINOMA - DETECTION BY IN-SITU END-LABELINGOF FRAGMENTED DNA AND CORRELATION WITH OTHER PROGNOSTIC FACTORS

Because stage and grade of renal cell carcinoma (RCC) sometimes fail t o predict the patient's outcome, additional prognostic predictors are needed. Apoptosis is a process of programmed cell death seen in both n ormal and neoplastic tissues, which has been shown to have prognostic significance in some tumor types. Forty-seven RCCs were studied for si ze, grade, stage, apoptosis, and proliferation. Fragmented DNA, a hall mark of apoptosis, was detected in situ by a process in which the frag mented DNA was labeled with a biotinylated nucleotide, which, in turn, was detected by an avidin-biotin-peroxidase labeling system. The prol iferating tumor cells were detected by immunostaining with the MIB-1 a ntibody. The apoptotic index and proliferation index of each RCC were expressed as the number of tumor cells undergoing apoptosis and prolif eration per 1,000 tumor cells. For grade I to IV RCCs, the median prol iferative index was 13, 41, 119, and 143; the median apoptotic index w as 8, 12, 39, and 73. For stage I to IV RCCs, the median proliferative index was 21, 34, 70, and 144; the median apoptotic index was 8, 9, 2 0, and 69. There was a statistically significant correlation of tumor grade, stage, and size with both proliferative index and apoptotic ind ex. There was a statistically significant correlation between prolifer ation index and apoptotic index. In conclusion. apoptosis can he easil y and reliably recognized by the in situ end labeling of fragmented DN A and may help predict the outcome of RCC. Copyright (C) 1996 by W.B. Saunders Company