Hormone Therapy for Prostate Cancer May Raise Heart Risks
Hormone therapy can be a lifesaver for men with prostate cancer, but it also appears to put some at increased risk of heart problems, a new study reports.
Long-term androgen deprivation therapy (ADT) increased the risk of heart-related death nearly fourfold in a group of prostate cancer patients, and also caused their heart fitness to decrease, researchers found.
There is one important caveat: These patients were not in great shape to begin with. At the start of the study, 4 out of 5 men had two or more risk factors for heart disease, the study says.
"Our data are not suggesting that androgen deprivation therapy definitely causes worse heart health," said lead researcher Dr. Jingyi Gong, a clinical fellow with the Brigham and Women's Hospital Heart and Vascular Center in Boston. "Rather, it suggests that for folks who are sicker on baseline with multiple cardiac comorbidities, they are more likely to deteriorate with androgen deprivation therapy from a cardiopulmonary perspective."
Doctors treating prostate cancer patients with poor heart health need to be vigilant regarding heart-related side effects of ADT, said Dr. Bonnie Ky, editor-in-chief of JACC: CardioOncology, the journal in which the study appears.
"We need to do everything we can to ensure the patients can receive lifesaving cancer therapy in a safe manner," Ky said.
About 1 in every 9 men will be diagnosed with prostate cancer during their lifetime, researchers said in background notes. It is the second-leading cause of cancer death in American men.
ADT combined with radiation therapy is a standard treatment for prostate cancer, researchers note.
Prostate cancer is fueled by male hormones, which are called androgens. Drugs that block production of testosterone are used to lower androgen levels in the body, with the aim of stalling out the cancer.
Prolonged use of ADT in some patients has become more popular lately, in the wake of studies that showed keeping men on hormone therapy improves their cancer outcomes. But questions have arisen about the effects of long-term hormone therapy on heart health.
This study tracked the heart health of 616 prostate cancer patients as they received hormone therapy for nearly five years after their cancer diagnosis.
All had an exercise treadmill test at the beginning of the study to determine their initial heart fitness, as well as a thorough analysis of their heart risk factors.
From the start, nearly 82% of the men had two or more heart risk factors -- smoking, high cholesterol, diabetes, high blood pressure, excess weight, family history of heart problems, symptoms of heart disease, and the like.
About one-quarter of the men (150) received ADT before their first treadmill test, and 51 had been exposed to long-term hormone therapy. Most patients with prolonged exposure to hormone therapy (92%) had two or more risk factors for heart disease.
Researchers found that men on long-term ADT were 3.8 times more likely to die from heart-related illness during the five-year follow-up, and they were 2.7 times more likely to perform worse on subsequent treadmill tests.
Blocking male hormone production causes a number of changes to men's bodies that could promote bad heart health, Gong said.
Men tend to lose lean muscle mass and pack on excess weight in the form of fat when their testosterone levels drop, Gong said.
Their insulin resistance and cholesterol levels also can go haywire, Ky added.
"We postulate it's all these things" increasing heart risk among prostate cancer patients, Ky said. "These factors are each modifying the cardiovascular risk."
Prostate cancer patients can fight these effects by sticking to a heart-healthy lifestyle, Gong said. That includes regular exercise, eating right, quitting smoking, managing blood pressure and cholesterol, and losing weight.
"If the treatment is indicated from a cancer survival perspective, then at the very least these patients should be encouraged to stay physically active and manage their comorbidities such as hypertension and diabetes," Gong said.
The American Heart Association has more on hormone therapy for prostate cancer.
SOURCES: Jingyi Gong, MD, clinical fellow, Brigham and Women's Hospital Heart and Vascular Center, Boston; Bonnie Ky, MD, editor-in-chief, JACC: CardioOncology; JACC: CardioOncology, Nov. 17, 2020