Hormone Therapy for Prostate Cancer Linked to Heart Risks
Tuesday, October 9, 2007; 12:00 AM
TUESDAY, Oct. 9 (HealthDay News) -- Prostate cancer patients receiving androgen-deprivation therapy, a common form of hormone treatment proven to slow tumor growth and prolong life, may face a nearly threefold higher risk of dying from heart disease, a new study suggests.
The apparent danger results from a drop in testosterone levels that is central to androgen-deprivation therapy's (ADT) effectiveness at curbing prostate cancer, the study authors said.
This drop in testosterone can provoke insulin resistance, leading to type 2 diabetes, as well as a gain in body mass, body fat and so-called bad cholesterol. Collectively, this group of problems is called the "metabolic syndrome," a condition long-associated with cardiac complications.
"However, I think overall ADT does help people with prostate cancer, and until it's studied further this can't be considered proof that there's a connection between the cardiac effects and hormone therapy," said study author Dr. Henry K. Tsai, who throughout the study period served as a resident in training in the Harvard Radiation Oncology Program in Boston.
"But patients need to think about being evaluated carefully by their doctor to see whether they're appropriate candidates for hormone therapy and be informed about the potential risks," Tsai added.
This new finding, published in the Oct. 17 issue of theJournal of the National Cancer Institute, follows research released in 2005 that highlighted ADT's link to an increased risk for bone fractures and osteoporosis.
The new findings are based on an analysis of medical records and questionnaires completed by nearly 4,900 patients between the ages of 39 and 86 who had been diagnosed with localized prostate cancer between 1995 and 2004.
All the patients had participated in a larger nationwide prostate cancer research project involving more than 13,000 men, during which all had indicated whether they had any preexisting medical complications in addition to cancer.
Of the 4,900 patients, nearly 3,300 had undergone prostate removal surgery following diagnosis.
The remainder underwent nonsurgical treatments, such as external beam radiation therapy; brachytherapy (involving the insertion of small radioactive pellets directly into the prostate); and/or cryotherapy (involving the freezing of tumor cells).
In addition, 266 of those patients who underwent surgery and 749 of those receiving an alternate treatment also received androgen-deprivation therapy.
The patients were tracked for an average of about four years following the start of all treatments; the patients receiving ADT did so for an average of about four months.