Hormone therapy is a common treatment option for prostate cancer, but it may increase the risk of death from heart disease, especially in older men, a new study finds.
Dr. William Dahut, a prostate cancer researcher and chief scientific officer for the American Cancer Society, said the study from Lithuania provides more evidence that starting hormonal therapy requires careful thought, particularly if the patient is over 70 and has heart disease.
"There are some cases where it's clear men need hormonal therapy," Dahut said, citing prostate cancer that has spread. "But oftentimes it's used for patients that are newly diagnosed, that are receiving radiation or with men that have a rising PSA [prostate specific antigen] without cancer that we can see, something called biochemical recurrence."
In terms of biochemical recurrence, "it needs to be looked at very carefully because there's much less data there that hormonal therapy will have an impact on how long patients live from prostate cancer," said Dahut, who was not involved in the study.
Doctors should consider whether to use hormonal therapy or how long to use it on a case-by-case basis, Dahut noted.
Hormone therapy, or androgen deprivation therapy, is considered a mainstay treatment for patients who have either high-risk localized prostate cancer or advanced cancer that has metastasized.
For the study, researchers used data from a Lithuanian cancer registry for patients ages 40 to 79 who had prostate cancer diagnoses between 2012 and 2016.
About 3,800 men received hormone-lowering drugs and more than 9,500 did not. In a follow-up roughly five years later, the researchers looked at overall death from heart disease and stroke.
They found a twofold increase in the risk of death from cardiovascular disease in men who had hormone therapy. They also found a higher risk of heart disease-related death from the second year onward after diagnosis.
Those who were 70 to 79 and had hormone therapy had an almost fivefold higher risk, according to the study published July 26 in the journal The Aging Male.
When looking at specific types of disease, the team found a 42% higher risk of dying from stroke and a 70% higher risk of dying from coronary heart disease in men who had hormone therapy.
"Prostate cancer is typically diagnosed in older men, over 65 years or older -- and many of them will have already been diagnosed with cardiovascular disease," lead author Justinas Jonusas, of the National Cancer Institute in Vilnius, Lithuania, said in a journal news release.
The results suggest clinicians should screen older prostate cancer patients for heart disease and related risk factors, Jonusas and other experts said.
Previous studies have not come to a clear conclusion about a link between the therapy and cardiovascular risk, the study noted. Moreover, the current observational study can't establish a direct cause-and-effect relationship.
Still, what can doctors do to treat one serious disease while not exacerbating another?
It may depend on the patient and his specific risks.
Men who are diagnosed with localized disease -- cancer that hasn't spread -- could undergo surgery, in which case they might not receive hormonal therapy, Dahut said. Those who opt for radiation may be able to do that without hormonal therapy or have a very short course of hormonal therapy.
“There is research ongoing now to be able to better differentiate which patients actually need hormonal therapy who are receiving radiation," Dahut noted.
In general, doctors and patients will need to assess potential risks and benefits, Dahut said.
Hormone therapy is not the only cancer treatment that can increase cardiovascular risk, said Dr. Katelyn Atkins, who specializes in cardiac radiation oncology at Cedars-Sinai Cancer Institute in Los Angeles.
"We think about all these different cancer therapies. They can all have a risk on the cardiovascular system from directly, like radiation, indirectly from hormonal therapy, but also immunotherapies, cytotoxic chemotherapies. They all work differently, but they can have overlapping and separate and distinct risks on the heart and the whole cardiovascular system," Atkins said.
Often, doctors will need to treat patients for their cancer despite heart risks, but after ensuring they're connected with a cardiologist to receive care.
It's important to understand that there are going to be some subgroups of patients that are at particularly high risk, Atkins added.
Those patients may need more stringent goals for their blood pressure and cholesterol numbers, she said.
Dahut said the medical community needs tools to better predict for whom hormonal therapy can be trivial and for whom it may be lifesaving.
"If we can do research to differentiate those populations, it will make the discussions much easier for patients and their physicians," Dahut said.
The U.S. National Cancer Institute has more on hormone therapy for prostate cancer.
SOURCES: William Dahut, MD, chief scientific officer, American Cancer Society, and professor, medicine, Uniformed Services University of the Health Sciences, Bethesda, Md.; Katelyn Atkins, MD, PhD, assistant professor, radiation oncology and associate director, Radiation Oncology Residency Program, Cedars-Sinai Medical Center and member, Cedars-Sinai Cancer Institute, Los Angeles; The Aging Male, journal and news release, July 26, 2022