Efficacy of intermittent androgen deprivation therapy vs conventional continuous androgen deprivation therapy for advanced prostate cancer: a meta-analysis

Abstract

Objective: To compare the efficacy of intermittent androgen deprivation therapy (IADT) vs continuous androgen deprivation therapy (CADT) for the treatment of advanced prostate cancer; we performed a meta-analysis of randomized controlled trials (RCTs), assessing the risks of disease progression, all-cause, and disease-specific mortality.

Materials and methods: We conducted a systematic search of several bibliographic systems to identify all RCTs of IADT in men with newly diagnosed metastatic or biochemical only prostate cancer. We abstracted outcome data, study characteristics, and participant demographics. We performed heterogeneity tests and calculated the summarized risk differences (RD) and risk ratios at 95% confidence intervals (CI), using inverse variance methods in random-effects approaches.

Results: We identified 8 RCTs (N = 4664) comparing mortality between IADT and CADT. For all men combined, we observed small but nonsignificant differences in all-cause mortality (RD = 0.02, 95% CI = -0.02, 0.06), disease-specific mortality (RD = 0.04, 95% CI = -0.01, 0.08), and disease progression (RD = -0.03, 95% CI = -0.09, 0.04). Among the prespecified subgroup with histologically confirmed, newly diagnosed metastatic disease, we found no difference in overall survival (RD = 0.00, 95% CI = -0.09, 0.09).

Conclusion: We found no difference in overall survival, but a small increased risk in disease-specific survival for men treated with IADT relative to CADT was observed. IADT could be considered as an alternative to CADT because of better quality of life outcome. Patients should be informed of the possible risks and benefits of both therapies. More research confirming the benefits of IADT vs CADT is needed to inform treatment decisions.

Figure 1

Flow chart of study selection.

Figure 2

Risk difference and risk ratio for comparative efficacy (all-cause and disease-specific mortality, disease progression) and risk of hot flushes between intermittent and continuous androgen deprivation therapy (IADT vs CADT) in 4664 men with advanced prostate cancer enrolled in 8 clinical trials. Studies are listed in an ascending order of median follow-up duration.