Pathologic changes associated with androgen deprivation therapy for prostate cancer.

Prostate glands exposed to androgen deprivation with leuprolide +/- flutamide were evaluated for pathologic changes which might be related to therapy. Comparing pretreatment and posttreatment tissue by visual discrimination using light microscopic study revealed treatment-related alterations in the size and distribution of neoplastic glands in 60% of cases. Quantitative measurements documented glandular changes in an even greater percentage of cases. Although distinctive, the histologic pattern was not specific for leuprolide/flutamide. The absence of appreciable degeneration and necrosis in tumor cells suggests that this type of androgen deprivation may act through suppression rather than ablation of prostatic cancers. The relationship between treatment-related histologic effects and initial tumor grade and clinical stage as well as expression of prostate-specific antigen was studied. Accurate histologic assessment of leuprolide/flutamide-treated prostate glands should not be a problem so long as specimens are thoroughly examined and drug-related variations in tumor morphologic features are appreciated.