History of CVD Adds to Risk
Men with a history of 2 or more cardiovascular events, with the latest having occurred within 1 year before initiation of androgen deprivation therapy, were at the highest risk of additional events during the 6 months after initiation of any of the three therapies (GnRH agonists: HR, 1.91; 95% CI, 1.66 to 2.20; antiandrogens: HR, 1.60; 95% CI, 1.24 to 2.06; orchiectomy: HR 1.79; 95% CI, 1.16 to 2.76). Risk declined in men on GnRH agonists and antiandrogens but remained high for up to 1 year in men who underwent orchiectomy.
Nevertheless, men with no history of cardiovascular disease were still at increased risk while on GnRH agonist therapy (HR, 1.19; 95% CI, 1.14 to 1.24).
The study authors speculated that the increased risk for cardiovascular events among men with prostate cancer given GnRH agonists or treated with orchiectomy may result from loss of the protective effect of testosterone.
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Antiandrogens do not reduce circulating testosterone and did not worsen cardiovascular risk in this study.
“Our study suggests an increased risk of CVD within the first year from starting GnRH agonist therapy or orchiectomy, especially in men with history of a CVD event within 1 year before ADT,” the study authors wrote.
“There should be solid indication of use of ADT so that the perceived benefit outweighs possible harm. This is particularly important in men with a recent history of CVD.”
- O’Farrell S, Garmo H, Holmberg L, et al. Risk and timing of cardiovascular disease after androgen-deprivation therapy in men with prostate cancer. J Clin Oncol. March 2, 2015. [Epub ahead of print] pii: JCO.2014.59.1792.