UPJ INSIGHT Comparison of Intermittent and Continuous Androgen Deprivation Therapy in Prostate Cancer Patients
By: Benjamin Becker, MD, Texas Tech University Health Sciences Center, School of Medicine, Lubbock; Stephanie Stroever, PhD, MPH, Texas Tech University Health Sciences Center, School of Medicine, Lubbock; Anish Reddy, MD, Texas Tech University Health Sciences Center, School of Medicine, Lubbock; Werner T. W. de Riese, MD, PhD, Texas Tech University Health Sciences Center, School of Medicine, Lubbock | Posted on: 25 Oct 2023
Becker B, Stroever S, Reddy A, de Riese WTW. Comparison of intermittent and continuous androgen deprivation therapy in prostate cancer patients: an up-to-date meta-analysis for urologists and medical providers. Urol Pract. 2023;10(5):424-434.
Study Need and Importance
Androgen deprivation therapy (ADT) has been the standard of care for recurrent, locally advanced, and metastatic prostate cancer (PCa) for many decades. The pharmacological development of luteinizing hormone-releasing hormone agonists in the 1980s led to the option of reversible medical castration and the idea of intermittent ADT (iADT). This clinical concept of iADT was first studied in in vitro tumor and animal models demonstrating extended preservation of hormonal response and increased time to castration resistance. Then followed clinical studies in humans. Although many urologists are administering iADT, current guidelines still recommend continuous ADT (cADT) over iADT. The purpose of this meta-analysis is to provide an update and guidance on these 2 forms of ADT.
What We Found
The data presented show that median follow-up was fairly consistent between the randomized clinical trials completed within the last 21 years. The meta-analysis did not show any advantage of cADT over iADT in PCa-specific mortality. As patients with PCa live for many years, we also compared non-PCa mortality (all other causes of death including other forms of cancer) under ADT, which revealed a trend of iADT to be advantageous over cADT although this did not reach statistical significance (see Figure).
This meta-analysis showed elevated heterogeneity in study protocols and wide confidence intervals due to inadequate patient recruitment, implicating that future studies must implement standardized protocols and focus on recruiting larger sample sizes with longer and similar follow-up periods.
Interpretation for Patient Care
Currently, iADT and cADT can be considered as equivalent in long-term treatment outcomes. As iADT is more cost-efficient (less financial toxicity) and less likely to yield adverse side effects under treatment, future guidelines should consider and emphasize these advantages of iADT in comparison to cADT.