An analysis of 12 clinical trials shows no difference in mortality risk with continuous versus intermittent androgen deprivation therapy for prostate cancer.
“For local recurrence after failed primary treatment and for locally advanced and metastatic disease, continuous androgen deprivation therapy (ADT) has been standard of treatment [in prostate cancer],” Werner de Riese, MD, PhD, and colleagues wrote. “However, intermittent ADT has emerged as a therapeutic alternative to continuous ADT. Although utilized for many years, there is presently much debate as to whether continuous ADT should still be recommended over intermittent ADT.”
For a study published in Urology Practice, Dr. de Riese and colleagues examined prospective randomized clinical trials (RCTs) in an effort to provide guidance on the selection of systemic ADT.
Both Treatments Associated With Favorable Results
In total, 12 studies met inclusion criteria for final analysis. The number of participants in the selected RCTs ranged from 31 to 1,386. The RCTs that examined mortality unrelated to prostate cancer included multiple other causes of death, including cardiovascular death and secondary cancer, among others.
A forest plot of the RCTs that assessed prostate cancer-specific mortality demonstrated that the average mortality surpassed the null line of no effect (NLNE), with deviation favoring continuous ADT. In the RCTs with data on mortality unrelated to prostate cancer, the average mortality crossing the NLNE had a deviation favoring intermittent ADT; these RCTs indicated that intermittent ADT was associated with a greater number of beneficial outcomes.
Mortality Risk Comparable With Both Types of ADT
The meta-analysis of the 12 trials indicates that there are no statistically significant differences in prostate cancer–specific or non-prostate cancer–specific mortality in patients who are treated with intermittent ADT versus continuous ADT, according to the researchers. As a result, “physicians may have greater confidence that neither treatment modality poses a greater risk [for] mortality than the other,” de Reise and colleagues wrote.
The researchers noted that “many urologists acknowledge the benefits of intermittent ADT.” They also acknowledged that intermittent ADT is more cost effective when combined with less treatment toxicity as a result of treatment holidays.
“Future guidelines should consider and emphasize these advantages of [intermittent ADT] in comparison [with continuous ADT],” de Reise and colleagues wrote.
