Role of Androgen Ablation with Low-Dose-Rate Brachytherapy in the??Treatment of Prostate Cancer

Abstract

Androgen ablation is often used in addition to low-dose-rate brachytherapy in the treatment of prostate cancer, particularly for disease with adverse features. We report a single-institution experience and analysis of the role of androgen ablation with brachytherapy in patients with prostate cancer. A cohort of 189 consecutive patients receiving low-dose-rate brachytherapy for prostate cancer at our institution who had demographic, disease and treatment information and a minimum of 2 years of follow-up available, constituted the analysis study group. This cohort was divided into two major categories based on the use of androgen ablation. Using two successive prostate- specific antigen (PSA) rises above 1 ng/mL as the definition of failure, biochemical failure-free survival (BFFS) curves were constructed for the androgen ablation and no-androgen ablation groups and compared using the log rank test; additionally, a multivariate analysis of all major disease and treatment factors was performed using the Cox proportional hazards model. These analyses were conducted for the whole cohort as well as for subgroups defined by the use of external beam radiotherapy (EBRT). The 4-year BFFS in the androgen ablation versus no-androgen ablation groups was 76% versus 70% (p = 0.230) for the whole cohort, 75% versus 62% (p = 0.182) for EBRT patients, and 75% versus 82% (p = 0.764) for no-EBRT patients. For the whole cohort, the use of EBRT was the only factor reaching significance on multivariate analysis (p = 0.040). When analysing the EBRT and no-EBRT subgroups separately, no factor, including androgen ablation, reached significance on multivariate analysis. In our study, addition of androgen ablation conferred no biochemical control advantage when added to low-dose-rate brachytherapy for the treatment of patients with prostate cancer.