Androgen deprivation therapy does not carry excess CV risk
MedWire News: Androgen deprivation therapy (ADT) does not increase the risk for cardiovascular (CV) death among men with unfavorable-risk, nonmetastatic prostate cancer, a meta-analysis of prospective randomized trials shows.
Furthermore, the findings confirm that ADT improves prostate cancer-specific survival and overall survival.
"The results of our study should be generally reassuring to most men with unfavorable-risk prostate cancer considering ADT," comment Paul Nguyen (Brigham and Women's Hospital, Boston, Massachusetts, USA) and colleagues in JAMA.
Several studies, including the National Surveillance, Epidemiology, and End Results-Medicare (SEER) database, have suggested that ADT causes excess CV mortality in men with prostate cancer.
Indeed, the American Heart Association and the American Cancer Society, among others, recently released a joint scientific report on the issue stating: "At this point, it is reasonable, on the basis of the above data, to state that there may be a relation between ADT and [CV] events and death."
Noting that most of the data raising concern has been retrospective, Nguyen et al performed a meta-analysis of prospective randomized trials published between January 1966 and April 2011.
They included studies involving immediate gonadotropin-releasing hormone agonist-based ADT versus no ADT or deferred ADT for men with nonmetastatic, unfavorable-risk prostate cancer. All studies had complete information on CV deaths and a median follow-up of more than 1 year.
From the eight suitable trials, involving 4141 patients, Nguyen et al report that CV death in patients receiving ADT (n=2200) was not significantly different from controls (n=1941), with 255 versus 252 events, respectively, giving an incidence of 11.0% versus 11.2%, and a relative risk (RR) of 0.93.
ADT was not associated with excess CV death in trials of at least 3 years (long duration) of ADT (incidence 11.5 vs 11.5%, RR=0.91), or in trials of 6 months or less (short duration) of ADT (10.5 vs 10.3%, RR=1.00).
Meanwhile, among 4805 patients (ADT=2527, control=2278) from 11 trials with overall death data, ADT was associated with lower prostate cancer-specific mortality (443 vs 552 events, incidence 13.5 vs 22.1%, RR=0.69) and lower all-cause mortality (1140 vs 1213 events, 37.7 vs 44.4%, RR=0.86).
Nguyen et al note that none of the trials were stratified by pre-existing CV comorbidity and therefore cannot exclude the possibility that a small subgroup of men with underlying cardiac disease, even if controlled, could experience excess CV mortality due to ADT.
"For these men it would seem prudent to continue to be mindful of possible metabolic and [CV] sequelae when using ADT."
By Andrew Czyzewski