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Only 10 percent of the 9 000 men in the US study who chose to delay or skip treatment had died of prostate cancer a decade later. The vast majority were alive without significantly worsening symptoms or had died of other causes.
Even the 30 percent who eventually sought treatment were able to delay it for an average of 11 years.
Over-treating the disease
"It is important news," said Dr Otis Brawley, chief medical officer
of the American Cancer Society. "It may persuade some
middle-of-the-roaders that we are over-treating this disease," and that
PSA testing may be amplifying the problem, he said. The PSA blood test
to help detect tumours has been widely used since the 1990s.
Grace Lu-Yao of Robert Wood Johnson Medical School in New Jersey led the study and will report results at a cancer conference later this week in San Francisco.
Whether to treat prostate cancer is one of the biggest medical dilemmas today. Most tumours grow so slowly they never threaten lives. Currently there is no sure way to tell which tumours will be deadly .
PSA tests can help find tumours many years before they cause symptoms, but routine screening of men at average risk of the disease is not recommended, because there is no proof it saves lives.
Prostate cancer treatments are tough, especially on older men. Many men are left with sexual or bladder control problems. Some doctors instead recommend "watchful waiting" to monitor signs of the disease and treat only if they worsen, but smaller studies have given conflicting views of the safety of that approach.
Watchful waiting tested
The new study looked at the natural course of the disease in men who
chose that option. It is the first involving so many older men - half
were over 75 - and so many whose tumours were found through PSA tests.
Using the federal government's cancer database, researchers studied 9 018 men diagnosed from 1992-2002 with early-stage prostate cancer who did not get surgery, radiation or hormone therapy for at least six months. Most never got any treatment at all.
A decade later, 3 percent to 7 percent of those with low- or moderate-grade tumours (rated by how aggressive the cells appear) had died of prostate cancer, versus 23 percent of those with high-grade tumours. Overall, prostate cancer killed 10 percent of them.
"The great majority of patients ... are going to die of something else," so most older men with early-stage tumours could delay treatment, Lu-Yao said.
"If people are younger or have more advanced disease, I wouldn't say this is a safe option," but most cases are diagnosed in men 68 or older, and most are early stage, she noted.
Not the final word
It is not the
final word - that usually comes from studies where similar groups of
patients are randomly assigned to get one treatment or another, and the
results compared. But in the absence of that kind of evidence, this large study
"does show that a large number of men do well with no initial treatment
and indeed with no treatment in the long term," Brawley said.
Dr Howard Sandler, a radiation and prostate specialist at the University of Michigan, agreed, but cautioned, "there are exceptions to every rule," and some very active, healthy older men may do better having treatment right away, along with older men who have higher-grade tumours.
Earlier this month, a scientific review published in the Annals of Internal Medicine concluded that evidence was too thin to recommend treatment over watchful waiting, or one treatment over another. Studies do show that prostate cancer surgery mostly helps men under 65, said Dr Timothy Wilt of the Minneapolis VA Centre for Chronic Disease Outcomes Research, who led the review.
The new study shows that for men older than that, "observation is a very reasonable approach," he said. "Many men do quite well for a long period of time with no treatment."
Although routine PSA testing is not recommended for all men, the cancer society does advise giving men information and the option to have it starting at age 50. Screening is recommended starting at age 45 for men with a family history of prostate cancer and for black men, because of their higher risk of the disease. – (Sapa-AP)
Read more:
Prostate Centre
Urine test spots prostate cancer
February 2008
