Prostate Cancer: Adding Zoledronate to Androgen Suppression and Radiotherapy Not Beneficial

Long-term use of zoledronate plus androgen suppression (AS) and radiotherapy (RT) does not improve outcomes among patients with advanced prostate cancer, according to research being presented at the 2018 Genitourinary Cancers Symposium in San Francisco, California.¹

For this phase 3 study (ClinicalTrials.gov Identifier: NCT00193856), researchers randomly assigned 1071 men with advanced prostate cancer to 1 of 4 study arms. Patients in the control arm received 6 months of neoadjuvant AS with intramuscular leuprolide 22.5 mg and RT alone (1), followed by an additional 12 months of AS (2), 18 months of zoledronate (3), or both (4). The median patient age was 68.7 years.

The median follow-up was 10.4 years. A significant reduction in prostate cancer–specific mortality — the primary outcome — was observed among patients who received 18 months of AS [hazard ratio, 0.70; 95% CI. 0.50-0.97; P = .035).

Patients also had significant improvements in secondary endpoints, including time to bone, distant, prostate-specific antigen, and local progression, and time to secondary therapeutic intervention.

Patients in the 18-month AS arms trended favorably towards time to soft tissue progression and all-cause mortality, but these findings were not significant.

The authors concluded that “18 months AS+RT is an effective option for locally advanced prostate cancer but the use of 18 months [zoledronate] is not beneficial.”

Read more of Cancer Therapy Advisor‘s coverage of the 2018 Genitourinary Cancers Symposium by visiting the conference page.

Reference

1. Joseph DJ, Lamb DS, Denham JW, et al. Ten year final results of the TROG 03.04 (RADAR) randomised phase 3 trial evaluating duration of androgen suppression + zoledronate for locally advanced prostate cancer. Oral presentation at: 2018 Genitourinary Cancers Symposium; February 8-10, 2018; San Francisco, CA.