The effect of bicalutamide on prostate histology

Nonsteroidal antiandrogens are commonly used in the treatment of prostate cancer, but more clinical and laboratory studies on patients with benign as well as malignant prostate diseases are required to define their exact role.

Light microscopic examination of perineal prostate biopsies of 21 men with BPH was performed pretreatment, after 24 weeks of therapy with 50 mg bicalutamide (Casodex) or placebo and 24 weeks after end of treatment. We assessed whether it was possible to distinguish between patients having received bicalutamide or placebo based on a general histological examination. In addition, the volume fractions of the prostatic epithelial, luminal, and stromal compartments were determined by morphometry.

Histological changes following treatment were uncharacteristic and patients treated with bicalutamide were not identified. At morphometry prior to therapy, the prostates of the study participants consisted of 91.8% stroma (range 78.9-97.2), 5.5% epithelium (range 1.4-14.1) and 2.7% glandular lumen (range 0.8-7.5). Changes in the relative content of the three tissue components following treatment were not statistically significant.

We did not observe consistent morphological changes in the prostate following treatment with bicalutamide at a dose of 50 mg daily. However, this dose is lower than the 150 mg dose presently recommended for bicalutamide monotherapy.