ORLANDO, FL, USA (UroToday.com) - This poster presentation attempted to address the question of whether continued androgen deprivation therapy with conventional agents (e.g., LHRH antagonists) is necessary for metastatic castration-resistant prostate cancer (mCRPC) patients as they move on to second generation androgen targeting agents or chemotherapy. This study looked at the outcomes of 36 mCRPC patients with continuous testosterone monitoring who remained on ADT while moving on to additional therapies. These patients underwent a variety of therapies including docetaxel, abiraterone acetate, enzalutamide, carboplatin, carbozantinib, and cabazitaxel.
At a median follow-up of 26.2 months, the authors found that patients with serum testosterone levels below 0.5 ng/dL experienced significantly longer overall survival compared to those with levels above 0.5 ng/dL (44 vs 17 months respectively, p=0.003). Patients with a testosterone level over 0.5 ng/dL had a 10-times higher risk of death compared to those with a testosterone level below 0.5 ng/dL (HR 10.2, 95% CI 2-50.7, p=0.005). PSA velocity greater than or equal to 0.5 ng/ml/day was also a significant predictor of death in this cohort (HR 3.51, 95% CI 1.13-10.87, p=0.03), but patient age, ECOG performance status, and primary Gleason score were not.
The authors concluded that continuation of conventional ADT and maintaining castrate-levels of testosterone remained important in patients with mCRPC moving on to chemotherapy and second-generation hormonal therapy. Further large-scale trials are necessary to confirm these conclusions.
Presented by Christopher A.J. von Klot, Alena Boeker, Thomas R.W. Hermann, Mario W. Kramer, Markus A. Kuczyk, and Axel S. Merseberger at the 2015 Genitourinary Cancers Symposium - "Integrating Biology Into Patient-Centric Care" - February 26 - 28, 2015 - Rosen Shingle Creek - Orlando, Florida USA
Reported by Timothy Ito, MD, medical writer for UroToday.com