MARCH 15, 2007


Docs debate merits of testosterone therapy

Fear of link to prostate cancer, heart disease unfounded: experts

Illustration credit: Sylvain Leblanc

Ever since the Women's Health Initiative was prematurely halted for safety reasons in 2002, any discussion about prescribing hormone therapy is bound to incite debate. The use of testosterone-replacement therapy (TRT) to treat symptoms of "male menopause," a rapidly growing field of research and an increasingly common clinical concern, is certainly no exception.

While some physicians maintain there just isn't enough data to be sure it's safe, others say the concerns — namely that TRT increases the risk of prostate cancer and heart disease — are unfounded and that physicians' reticence is depriving millions of Canadians of treatment. Experts debated the merits of TRT at the recent 2nd North American Congress on the Aging Male, held in Montreal in early February.

The number of TRT prescriptions filled in Canada has more than doubled since 1999 — to over 300,000 last year alone. But that number should be several orders of magnitude higher still, according to Dr André Guay, a Harvard professor and endocrinologist who participated in the recent debate. He says there's a persistent lack of knowledge about testosterone deficiency in the medical community at large. "Low testosterone and reproductive hormones have fallen through the cracks. Those things aren't treated much by endocrinologists, just by very specialized centres now," he explains. "And until recently, most doctors trained as FPs were trained in hospitals, but low testosterone is not an inpatient issue."

Yet two to three million Canadians will have testosterone deficiency in their lifetimes, according to Dr Jay Lee, a University of Calgary urology professor who also took part in the debate. He says the majority of them are candidates for TRT — a prospect that makes many physicians who are still unsure of the treatment's safety very uneasy.

Though he admits more research is needed, Dr Guay says TRT appears to be safe and effective for a variety of health issues caused by testosterone deficiency, including erectile dysfunction, low libido, osteoporosis, reduced muscle mass and low energy. Even patients with metabolic syndrome, he says, can benefit from TRT.

"There is a shift," agrees Dr Lee. "In the old days, we all thought that testosterone was bad for the heart, for example, because more men have MIs and die of heart attacks [compared to women]. We thought estrogen protects the heart, but now we know it probably doesn't. In fact, low testosterone is associated with heart problems."

Dr Lee is quick to point out that although there is evidence that testosterone deficiency is harmful to the heart and associated with metabolic syndrome, there has never been an outcome study to measure those relationships. A new meta-analysis, published in the journal Mayo Clinic Proceedings in January, however, did show that TRT is likely safe for the cardiovascular system. Dr Lee, at least, is convinced — he regularly prescribes TRT to men with metabolic syndrome as an adjunctive treatment, to give them the extra energy to start exercising.

For many TRT-tenderfoots, the concern about the therapy's purported connection to prostate cancer is even more disquieting. "There are a lot of misconceptions," Dr Guay counters. "A lot of people think it causes prostate cancer, but there is no really good data that it does."

The link between testosterone and prostate cancer was first proposed in 1941 by a Halifax-born physician named Charles Huggins, whose work on the prostate cancer-hormone relationship was so widely respected that it garnered him the 1966 Nobel Prize for Physiology or Medicine. But the literature has since discredited the connection.

"One of the principles of evidence-based medicine is that concepts that fail to withstand scientific scrutiny are to be discarded," wrote one of the field's current leaders, Dr Abraham Morgentaler, in European Urology in October of last year. "Such a time has come for the belief that testosterone causes enhanced growth of prostate cancer."

TRT should not, however, be prescribed to patients who have prostate cancer already, warns Dr Lee.

So how do you know if your patient is suffering from testosterone deficiency? It's clear that testosterone levels decrease with age and that the hormone loss can be exacerbated by stress, anxiety and chronic illness, adds Dr Guay. Diabetics often have testosterone deficiency, as do men with sleep apnea, osteoporosis and erectile dysfunction (ED). "If you check every man who comes into your office with ED, only 5-8% will have low testosterone," says Dr Lee. "If someone has low libido plus ED, that goes up to 20-25%. Then, of those with ED who fail on an ED drug, 35% of them will have low testosterone."

But you'll need to get biochemical tests (salivary tests and blood tests are available) to diagnose a patient with certainty, explains Dr Guay, because some of the symptoms can coincide with those common in depression or low thyroid function.

Dr Guay accepts that some doctors have concerns about TRT, but he insists that it can be of great benefit for the right patients.

"There is some risk," acknowledges Dr Lee, of some potential side effects such as skin irritation, benign prostate growth and urinary problems, gynecomastia, infertility and others. "But as long as you are checking on [your patients] often and talking to them about the pros and cons," he says, "I believe you are doing them a great service."



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