GnRH agonist therapy leads to much higher risks than antiandrogens.
Scientists suggest some types of hormone therapy used to treat advanced prostate cancer may significantly increase the risk of patients developing and even dying from heart conditions including coronary heart disease and myocardial infarction. These problems also appeared to start within a few months of initiating treatment, claim King’s College London’s Mieke Van Hemelrijck and colleagues. The study is reported at ECCO 15–34th ESMO Multidisciplinary Cong ress.
The scientists found that prostate cancer patients prescribed GnRH agonists demonstrated a 34% increased risk of heart failure and a 30% higher likelihood of developing ischemic heart disease than people in the general population. This compared with only a 5% increased risk of heart failure and a 13% increased risk of ischemic heart disease among patients prescribed antiandrogens.
The study included 30,642 Swedish men with locally advanced or metastatic prostate cancer who received hormone therapy as primary treatment. They were followed for an average of three years. The research is the largest to investigate the relationship between a broad range of hormone therapies and a number of different heart problems, according to the scientists.
“We found that prostate cancer patients treated with hormone therapy had an elevated risk of developing all of the individual types of heart problems and that they were more likely than normal to die from these diseases,” reports Van Hemelrijck. “If we have observed a causative effect, then for all hormone therapies put together, we estimate that compared with what’s normal in the general population, about 10 extra ischemic heart disease events a year will happen for every 1,000 prostate cancer patients treated with such drugs.”
The results suggest that overall, prostate cancer patients treated with hormone therapy had a 24% increased risk of a nonfatal heart attack, a 19% increased risk of arrhythmia, a 31% higher risk of ischemic heart disease, and a 26% increased risk of heart failure. The risk of a fatal heart attack was elevated by 28%, the risk of dying from heart disease was increased by 21%, and the likelihood of death due to heart failure was 26% higher.
The researchers conclude that doctors should seriously consider the potential for heart-related side effects before prescribing endocrine therapy for prostate cancer and possibly refer individual patients to a cardiologist before starting treatment.