Short-course androgen ablation combined with external-beam radiation therapy and low-dose-rate permanent brachytherapy in early-stage prostate cancer: a matched subset analysis.

Abstract

Background and purpose: In order to evaluate the effect of short-term androgen blockade on biochemical control rates for high-risk patients receiving a combination regimen of external-beam radiation therapy and low-dose-rate permanent seed implant brachytherapy, a retrospective matched subset analysis was performed.

Patients and methods: Inclusion in the high-risk cohort required at least two of the following poor prognostic factors: serum prostate specific antigen (PSA) concentration > or = 10.0 ng/mL, Gleason score > or = 7, or clinical stage T(2c) or T(3a) disease. Twenty-one patients who underwent androgen ablation between June 1991 and December 1995 in addition to combined-modality radiation therapy qualified as high risk, as did 77 patients who underwent combined-radiation therapy only. There was no statistically significant difference between the two groups in terms of follow-up (mean 44.6 v 47.8 months, respectively), pretreatment PSA, clinical stage, biopsy Gleason score, or the presence of all three poor prognostic factors.

Results: The overall rates of freedom from biochemical failure at 5 years were 77% in the hormonally treated group and 58% in the nonhormonally treated group. The difference was not statistically significant by log rank test (P = 0.08).

Conclusion: Longer follow-up with larger patient numbers is needed to define the role of adjuvant androgen ablation combined with radiation therapy.