Prostate cancer hormone therapy does not appear to increase cardiac deaths

In a new study that appears to refute earlier research, Massachusetts General Hospital researchers have found that treating prostate cancer patients with gonadotropin-releasing hormone (GnRH) agonists does not appear to increase the risk of death from cardiovascular disease.

While a 2006 report from members of the same study team found that the treatment increased the risk of diabetes and heart disease, the current study is the first to examine whether treatment actually increased heart disease-related deaths.

The researchers, whose current study appears online in the Journal of Clinical Oncology, note that GnRH agonist treatment has a number of adverse side effects, which should be kept in mind when determining treatment strategies.

“Hormonal therapy for prostate cancer has become routine for many patients, so it’s even more important to understand the potential adverse effects of treatment,” said lead author Jason Efstathiou, MD, DPhil. “Given recent concerns about the safety and impact on cardiac health of hormonal therapies-particularly GnRH agonists-our study is quite timely.”

To specifically investigate the relationship between GnRH agonist therapy and death from cardiovascular disease, the current study analyzed data from a 1987 to 1992 clinical trial in which almost 1,000 patients were treated for locally advanced prostate cancer with either the GnRH agonist goserelin (Zoladex) plus radiation therapy or radiation therapy alone.

During the decade following completion of the trial, more than half of the participants died from various causes. Of the 574 deaths, 117 were from cardiovascular disease, but whether or not patients had received the GnRH agonist apparently had no effect on the risk of cardiovascular death. Instead, it was established cardiac risk factors, including heart disease or diabetes that existed prior to GnRH agonist treatment, that appeared to increase the risk of dying from cardiovascular disease.