PROGRESSIVE INCREASE OF APOPTOSIS IN PROSTATIC INTRAEPITHELIAL NEOPLASIA AND CARCINOMA - COMPARISON BETWEEN IN-SITU END-LABELING OF FRAGMENTED DNA AND DETECTION BY ROUTINE HEMATOXYLIN-EOSIN STAINING

Objective.-Apoptosis has attracted significant attention in the study of tumors during recent years. The first goal of this study was to eva luate the number of apoptotic cells and bodies in benign glands, in hi gh-grade prostatic intraepithelial neoplasia, and in malignant prostat ic glands. The second objective was to compare the effectiveness of in situ end-labeling of fragmented DNA (ISEL) with the use of routine he matoxylin-eosin (H&E) stains in the assessment of apoptosis rates. Met hods.-The percentage of apoptosis was measured with ISEL and H&E stain s in sections from 16 prostatectomies performed for previously untreat ed peripheral prostatic adenocarcinomas. Results.-Both methods showed progressive increase of the rates of apoptosis from benign glands (0.3 4% to 0.38%), to high-grade prostatic intraepithelial neoplasia (1.44% to 1.39%), to carcinoma (2.69% to 2.75%). The increase in apoptosis r ate in prostatic intraepithelial neoplasia and carcinomas is one more indication of the continuum in the pathogenetic process leading to inv asive prostatic carcinoma. Student's t test revealed no statistically significant difference in the percentage of apoptosis rendered by ISEL and H&E staining. Conclusions.-From a practical point of view, evalua tion of apoptosis with H&E stains can be readily performed using routi ne clinical material. The procedure is inexpensive, and it gives good tissue morphology. However, quantitative measurements may be time-cons uming and observer-dependent. The apoptotic bodies are clearly identif iable with ISEL, making quantitation easy and even amenable to automat ed counting methods. Disadvantages of ISEL are significantly higher co sts and poor tissue morphology. We conclude that accurate evaluation o f apoptosis may be performed reliably with both routine H&E staining a nd the ISEL method. The decision to choose one method over the other d epends on the economic resources available and the amount of material to be evaluated.