Efficacy of neoadjuvant bicalutamide and dutasteride as a cytoreductive regimen before prostate brachytherapy

To evaluate the cytoreductive effectiveness of combined neoadjuvant bicalutamide and dutasteride before prostate brachytherapy for clinically localized prostate cancer.

From April 2003 to May 2005, 31 patients opted for cytoreduction with bicalutamide (50 mg daily) and dutasteride (0.5 mg daily). Before, and at 3 months (90 +/- 5 days) after, the initiation of medical therapy, all patients underwent a transrectal ultrasound volumetric study of the prostate gland, with ellipsoid volume determination of the prostate gland and transition zone. The variables analyzed included pretreatment and posttreatment prostate and transition zone volumes and changes in width, height, and length of the prostate gland and transition zone. A multivariate analysis was performed to identify predictors for prostate gland and transition zone volume reduction.

Before the initiation of bicalutamide and dutasteride, the mean prostate volume was 54.3 cm3 by planimetric summation and 49.7 cm3 by ellipsoid volume calculation. After a 3-month course of combination medical therapy, the average prostate volume was 36.1 cm3 (33.6% reduction) and 32.5 cm3 (34.6% reduction) using the volumetric and ellipsoid volume determinations, respectively. Bicalutamide and dutasteride resulted in a 39.8% reduction in transition zone volume (20.8 cm3 versus 12.4 cm3). The prostate gland and transition zone dimensions (width, height, and length) decreased about 11.4% to 19.9%.

The prostate gland and transition zone volume reductions after a 3-month course of neoadjuvant bicalutamide and dutasteride are comparable to previous reports of volume reduction using a luteinizing hormone-releasing hormone agonist with or without an antiandrogen.