The first controlled study comparing three different approaches to prostate cancer — radiation versus surgery versus "watchful waiting" — shows there is no truly bad choice for most men, experts said Wednesday.
The British study won't end debates over whether prostate cancer screening is a good idea, but it should reassure many men that it's OK to make their own decisions about whether and how to treat prostate cancer if they get diagnosed.
While tumors were more likely to grow and spread in men who got no treatment compared to those who did, it was still rare, and it was even more rare for men to die from prostate cancer. Out of 1,600 men who took part in the 10-year study, just 17 died of prostate cancer, the researchers reported in the New England Journal of Medicine.
Prostate cancer is very common, showing up in 240,000 U.S. men every year. It kills about 30,000 a year.
Dr. Freddie Hamdy of Oxford University and colleagues said there were not enough deaths to say whether men who got surgery, radiotherapy or who just did the watchful waiting were any more likely to die.
"What we have learnt from this study so far is that prostate cancer detected by PSA blood test grows very slowly, and very few men die of it when followed up over a period of 10 years — around 1 percent — irrespective of the treatment assigned. This is considerably lower than anticipated when we started the study," Hamdy said in a statement.
Dr. Otis Brawley of the American Cancer Society, who was not involved in the research, said while men who waited for treatment were twice as likely to have their cancer spread, it was nonetheless a very low number.
"The study shows that there is twice as much metastatic disease in the observed group," he told NBC News.
"But the truth is, it's 6 percent versus 3 percent at 10 years. Yes, it is twice as much but it is much less than even I thought it would be."
The bigger problem is determining at diagnosis which men have potentially lethal disease, Hamdy and Brawley both said — and this study does not answer that question.
Dr. Anthony D'Amico, a prostate cancer expert at Harvard Medical School and Brigham and Women's Hospital, said men do not need to fear they might die because they have not chosen the "right" course of treatment.
"Men with low-risk or intermediate-risk prostate cancer should feel free to select a treatment approach using the data on health-related quality of life and without fear of possibly selecting a less effective cancer therapy," D'Amico, who was not involved in the research, wrote in a commentary.
In most men, prostate cancer isn't likely to kill them before other something else does. Wednesday's study suggests that men who expect to live 10 years or less — usually very elderly men — don't need to bother with treatment, experts said.
But there's disagreement over when and how to treat men who do have prostate cancer.
So Hamdy and colleagues across Britain enlisted men for what's considered the most reliable type of medical experiment — randomly assigning large numbers of people to different treatments to see which ones do better.
They got 1,600 men with prostate cancer aged 50 to 69 to agree to be randomly assigned to surgery, radiation therapy or "watchful waiting," which involves regular checks. If cancer does start to progrsss, the men get treatment.
Over 10 years, 204 of the men had their cancer grow or spread, the team reported.
Not surprisingly, this was more common among men who got no treatment but who were watched — 112 of them had their cancer progress, compared to 46 men in each of the other two groups.
"On the basis of our results, we estimated that 27 men would need to be treated with prostatectomy rather than receive active monitoring to avoid one patient having metastatic disease," they wrote.
The team also asked the men about side-effects. The prostate is in a delicate area and both surgery and radiation treatment can damage the tissues nearby, affecting sexual function and the ability to control urination and the bowels.
Radiotherapy affected sexual function for the first six months and did not affect continence, they found.
After six years, twice as many men in the group who got surgery still complained of urine leakage and problems with their sex life. Radiation therapy caused more bowel problems than surgery or active monitoring.
"Each treatment has different impacts and effects, and we need longer follow up to see how those balance out over the next 10 years," said Jenny Donovan of the University of Bristol, who headed the side-effects study team.
And although "watchful waiting" did allow cancer to progress — potentially requiring more serious treatment than otherwise might have been needed — some men said it's the best choice for them.
Clark Howard is one of them. The 61-year-old radio talk show host has been watching and waiting ever since he was diagnosed with early stage prostate cancer.
He says the "watchful" part of the "watchful waiting" approach is key.
"The truth is, what happens with most men, once they are on active monitoring, they don't do what they're supposed to do," Howard said.
At first, Howard got a prostate-specific antigen (PSA) test every 90 days and biopsies every six months. That's now been gradually extended to every two years and he said his last three biopsies have shown no cancer.