Cardiovascular Disease Risk in Prostate Cancer Patients on ADT

March 24, 2015

A new study suggests that men with a history of cardiovascular disease prior to starting ADT are at risk for such events during the first 6 months of treatment.

The US Food and Drug Administration (FDA) requires a risk label on gonadotropin-releasing hormone (GnRH) agonists-a type of androgen deprivation therapy (ADT)-that indicates the increased risk of cardiovascular disease and diabetes in prostate cancer patients. The risk label is based on population-based studies that examined the risk of cardiovascular disease, including heart attack, stroke, and sudden cardiac death. Still, the link between various types of ADT and cardiovascular disease is not clear because of the varying outcomes of analyses of randomized clinical trials.

In an expansion of the Prostate Cancer Database (PcBaSe) Sweden study, a new study suggests that men who have a history of cardiovascular disease events prior to starting ADT are at risk for cardiovascular disease during the first 6 months of treatment. The results of the study were published in the Journal of Clinical Oncology.

Mieke Van Hemelrijck, PhD, co-director of the cancer epidemiology group at King’s College London, School of Medicine, and colleagues utilized data on filled prescriptions in Swedish national healthcare registers between 2006 and 2012, to analyze the risk of cardiovascular disease among 41,362 men with prostate cancer undergoing treatment with ADT compared with 187,785 prostate cancer–free, age-matched men.

The prostate cancer patients in the study were taking either anti-androgens or GnRH agonists, or had undergone a surgical orchiectomy.

The men on GnRH agonists had a 21% increased risk of cardiovascular disease compared with the cancer-free cohort. Men who underwent an orchiectomy had a 16% increased risk of cardiovascular disease. Men taking anti-androgens had a 13% lower risk of cardiovascular disease compared with the healthy cohort. The risk of cardiovascular disease was similar among men whose ADT regimen was as a primary treatment for their prostate cancer.

Cardiovascular disease risk was highest during the first 6 months of ADT in men who had had two or more cardiovascular events before beginning the regimen. In this subset of men, the increased risk of cardiovascular disease while being treated with anti-androgens, GnRH agonists, or orchiectomy (hazard ratios of 1.60, 1.91, and 1.79, respectively) was consistent. Between 6 and 12 months of therapy, the risk for men taking anti-androgens or GnRH agonists decreased, while the risk for men who had an orchiectomy increased.

“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 cardiovascular disease,” concluded the study authors.

In an accompanying editorial, Shehzad Basaria, MD, of Brigham and Women’s Hospital and Harvard Medical School in Boston, wrote that a prospective study powered to evaluate cardiovascular events in men undergoing ADT is warranted because “there is a large body of data showing worsening of the metabolic profile in men undergoing ADT.” Coronary artery plaque measurements, among other cardiovascular measurements, should be monitored to better understand the impact of ADT on vascular biology.