PATHOLOGICAL-CHANGES IN BENIGN AND MALIGNANT PROSTATIC TISSUE FOLLOWING ANDROGEN DEPRIVATION THERAPY

Several retrospective studies, as well as prospective trials, have dem onstrated that neoadjuvant total androgen ablation therapy leads to in volutional changes in prostatic carcinoma and may have the potential t o downstage operable prostate cancer. Following androgen deprivation t herapy, virtually all prostates contain residual adenocarcinoma, altho ugh it may be extremely focal in up to 25% of cases. Morphological cha nges observed in treated prostatic adenocarcinoma include loss of glan dular architecture, cytoplasmic vacuolization, and nuclear pyknosis. I nvolutional changes may be so dramatic that pathologists unaware of th ese changes will have difficulty in identifying residual disease. Simi lar changes may be seen in metastatic sites. Electron microscopy of tr eated tumors suggest that involution is due to programmed cell death ( apoptosis). High grade prostatic intraepithelial neoplasia is present less frequently and usually only focally. Treated carcinoma exhibits a paradoxical high Gleason score but its proliferation rate and degree of aneuploidy is less than grade-matched, untreated tumors. Thus, grad ing of pretreated adenocarcinoma by conventional methods may be mislea ding and should be avoided. Treatment-related changes are also present in benign prostatic tissue and these include glandular atrophy, basal cell prominence and hyperplasia, and stromal hypercellularity. Severa l studies suggest pathologic downstaging of the tumor, but it remains unclear whether this finding will result in increased local control. ( C) 1997 by Elsevier Science Inc.