Healthy men who are regularly screened for prostate cancer and show no symptoms
should talk to their doctors about taking a hormone-inhibiting drug to prevent
the disease, new U.S. guidelines recommend.
Prostate cancer is the second-leading cause of cancer death in men after lung
cancer. In Canada, about 25,000 men will be diagnosed this year with the
malignancy and about 4,300 will die of the disease.
The guidelines, released yesterday by the American Society of Clinical Oncology
and the American Urological Association, recommend that healthy men consider
taking finasteride, which belongs to a class of drugs known as 5-alpha reductase
inhibitors, or 5-ARIs.
The medications lower the level of the hormone dihydrotestosterone, which can
contribute to the growth of prostate cancer. The drugs, sold under such brand
names as Proscar, Propecia and Finpecia, are used to treat other non-cancerous
conditions such as male-pattern baldness and benign prostatic hyperplasia.
The panel based its recommendations on several studies in particular
theProstate Cancer Prevention Trial (PCPT) which compared finasteride against
placebo in healthy men over 55, who were receiving regular screening tests for
prostate cancer. Participants took the drug for one to seven years. The results
showed that finasteride can reduce the relative risk of the disease by about 25
per cent.
But panel co-chair Barry Kramer, associate director for disease prevention at
the U.S. National Institutes of Health, stressed that the group is not
recommending that all men take 5-ARIs. The recommendations are not that they
take it, but that the health issue is important enough that a discussion as part
of the periodic checkup is worthwhile.
Dr. Kramer said taking 5-ARIs appears to confer other benefits, including a
lower incidence of urinary retention. But they can also cause side effects in
some men, among them erectile dysfunction, impotence and breast tenderness.
When the PCPT was published in 2003, there appeared to be an increased risk for
high-grade tumours among men taking the drug, compared to those taking a dummy
pill. But subsequent tissue analysis showed prostate tumours that occurred among
the drug-taking group were smaller, less dangerous and less invasive.
The guideline will be published in next month's issues of the Journal of
Clinical Oncology and the The Journal of Urology.
