Hormone therapy is a common treatment for prostate cancer, but researchers at the Yale Cancer Center are reporting that it may do more harm than good to some patients who have previously suffered a heart attack.

The study, “Assessing Potential Cardiovascular Risk Against the Benefits of Hormonal Therapy in Men With Intermediate-Risk Prostate Cancer,” was recently presented at the American Society for Therapeutic Radiology and Oncology (ASTRO) Meeting in Boston.

Prostate cancer cells rely on male sex hormones (androgens) to grow. For this reason, hormone therapy is used  to suppress the production of such hormones or their ability to bind to specific receptors, stopping the spread and growth of the tumor cells.

Researchers used a decision analysis model — from a previously study that had compared quality-adjusted life expectancy (QALE) in men age 50, 60, and 70 who received radiation therapy for high-risk prostate cancer and stratified by cardiac risk — to evaluate treatment options for men with mostly intermediate-risk prostate cancer also grouped by cardiac risk.

Specifically, they analyzed data from the recently published EORTC 22991 trial (NCT00021450), which included from 819 patients with intermediate-risk (74.8 percent) and high-risk  (24.8 percent) prostate cancer, and an average age of 70. Participants were randomly assigned to receive either radiation therapy (409 patients) or radiation therapy plus six months of hormone therapy (410 patients).

At eight-years of follow-up, hormone therapy was associated with a decrease of 0.3 to 0.4 in quality-adjusted life expectancy in men with a history of heart attack. For other men, the therapy improved quality-adjusted life expectancy (range 0.4-2.6).

Younger patients with fewer cardiac risk factors benefited the most from hormone therapy. But men with low risk for biochemical recurrence, which is defined by raised PSA levels, had no gain from hormone therapy, the researchers found — suggesting it is not advisable for those with a cardiac history.

“Patient age, cardiac risk, and disease recurrence risk should be considered when selecting candidates for hormone therapy in this patient population,” Nataniel Lester-Coll, MD, the study’s first author and a resident in the Department of Therapeutic Radiology at Yale School of Medicine, said in a news release. “Men with a history of heart attack who are at very low risk for biochemical failure may be harmed by the addition of hormone therapy.”

EORTC 22991 trial results were also presented at the ASTRO meeting. The abstract was titled “EORTC trial 22991: Results of a phase III study comparing 6 months of androgen suppression and irradiation versus irradiation alone for localized T1b-cT2aN0M0 prostate cancer.”