• E-mail
• Print
• Comment
• Font Size
• Digg
• del.icio.us
• Discuss article

Prostate Cancer Treatment Has Health Risks

Posted on: Tuesday, 19 September 2006, 06:00 CDT

By Liz Szabo

For the first time, research shows that hormone therapy, a common treatment for prostate cancer, can raise the risk of diabetes and heart disease.

Experts say the study suggests that doctors should be cautious when prescribing the drugs, especially to men with limited disease and a long life expectancy, who may have the least to gain and the most to lose from the treatment.

Hormone therapy, which lowers levels of the testosterone that feeds prostate cancers, is a mainstay of treatment for prostate cancers that have spread to the bone. The drugs, typically given as injections every one to four months, can't cure prostate cancer. They may slow its growth, however, and relieve pain. Many men in advanced stages of the disease choose to have the shots, in spite of their side effects: osteoporosis, muscle loss, fat gain, hot flashes and impotence, says the study's main author, Nancy Keating, an assistant professor at Harvard Medical School.

Research has never proved that hormone therapy can help men with less extensive disease, Keating says. Yet more and more men treated with surgery or radiation for "local" or "regional" tumors -- those confined to the prostate or nearby lymph nodes -- are taking hormone therapy if blood tests suggest their cancer may have returned, she says. Many of these men have no signs of the disease other than a cancer-related protein in their blood, called PSA.

Some of these men may need no further treatment, says Otis Brawley, a professor at Emory University in Atlanta who was not involved in the study. Men with this type of cancer live a median of about a decade before their tumors cause any symptoms. That makes it important to preserve their long-term health.

Keating and her colleagues were concerned to find the risk of diabetes and heart disease rise in as little as a few months. Researchers examined the records of 73,000 Medicare participants diagnosed between 1992 and 1999. Doctors were able to follow the men's progress for an average of 4.5 years, according to a study released Monday in the Journal of Clinical Oncology. According to the study, if doctors treat 1,000 men with hormone therapy for a year, doctors would find 29 cases of diabetes, eight more than among men not treated; 14 heart attacks, three more than among men not treated; and 13 sudden cardiac deaths, four more than among men not treated.

"It raises the question that maybe this is not the right drug for these early-stage cancers," Keating says. "If the prostate cancer isn't going to progress on its own, why are we giving them other diseases? For pure prevention, we probably shouldn't be giving potentially toxic medication until we know there is a clear benefit."

Brawley says the study's design and size make it very powerful, even though doctors did not conduct a true experiment, one in which patients who are assigned the drugs are compared with patients who don't take the therapy. Such a study would be too difficult and expensive, he says.

Because Keating's study is the first to find these increased risks, she says researchers should try to confirm her results. Still, Howard Scher of New York's Memorial-Sloan Kettering Cancer Center says the study probably will change the way doctors talk to their patients about risk.

Scher suggests that doctors should consider patients' heart health before prescribing hormone therapy. Physicians also should help patients reduce their risks through diet and exercise and carefully monitor patients' blood sugar, cholesterol and other measures.

Brawley says he will show the study to patients who are considering hormone therapy. Many such patients might be better served through watchful waiting.

Brawley says doctors are learning more about which patients may get the most from hormone therapy. Research shows that men whose PSA level doubles in a short amount of time, for example, are at very high risk of a life-threatening relapse and may benefit most from the therapy.

(c) Copyright 2005 USA TODAY, a division of Gannett Co. Inc.

Source: USA TODAY

More News in this Category