WASHINGTON – The cardiovascular effects of androgen deprivation therapy (ADT) for men with advanced prostate cancer are less severe than once feared, but there is evidence to suggest that men with preexisting heart failure or a history of myocardial infarction could be at excess risk for death from cardiovascular causes when they receive ADT, according to a leading prostate cancer expert.
“I think there are concerns about potential cardiovascular harm of ADT, and I think this has reduced ADT use, despite the fact that we know for most men it improves overall survival,” said Paul Nguyen, MD, a radiation oncologist at the Dana-Farber/Brigham and Women’s Cancer Center in Boston.
“In fact, when we looked recently at men with high-risk prostate cancer, this is a group where overall survival is improved by 50% if they get ADT – so it cuts the risk of death in half – but it turns out that nearly a quarter of those patients are not receiving ADT. I think that the concern about cardiovascular harm and the confusion as to where that data stands is a lot of what’s driving that right now,” he said at the American College of Cardiology’s Advancing the Cardiovascular Care of the Oncology Patient meeting.
Randomized trial data
Dr. Nguyen noted that the evidence suggesting that ADT can increase the risk of death from cardiovascular causes came largely from three major studies:
- A 2006 study of 73,196 Medicare enrollees aged 66 or older, which found that ADT with a gonadotropin-releasing hormone (GnRH) agonist was possibly associated with increased risk of incident diabetes and cardiovascular disease (J Clin Oncol. 2006 Sep 20;24[27]:4448-56.).
- A 2007 analysis of data from the Cancer of the Prostate Strategic Urologic Research Endeavor (CAPSURE) database on 3,262 men treated with radical prostatectomy and 1,630 men treated with radiation or cryotherapy for localized prostate cancer, which found that among those 65 and older the 5-year cumulative incidence of cardiovascular death was 5.5% for patients who received ADT, vs. 2% for those who did not (J Natl Cancer Inst. 2007 Oct 17;99[20]:1516-24).
- A 2007 study of 1,372 men in three randomized trials of radiation therapy with or without androgen suppression therapy up to 8 months in duration, which found that men 65 and older who received 6 months of androgen suppression had significantly shorter times to fatal MIs than did men who did not receive the therapy (J Clin Oncol. 2007;25[17]:2420-5).
These studies, combined with observational data, led to a 2010 consensus statement from the American Heart Association, American Cancer Society, and American Urological Association, with endorsement from the American Society for Radiation Oncology, which stated that “there may be a relation between ADT and cardiovascular events and death.”
Also in 2010, the Food and Drug Administration required new labeling on GnRH agonists warning of “increased risk of diabetes and certain cardiovascular diseases (heart attack, sudden cardiac death, stroke).”