TORONTO - Canadian researchers are launching a large, multi-year international study to try to find a way to help the hundreds of thousands of men diagnosed with prostate cancer every year decide whether to opt for potentially life-altering treatments or choose a watch-and-wait approach.
The Canadian Cancer Society and the National Cancer Institute of Canada announced the study Thursday, saying it is hoped the START trial - the acronym stands for Surveillance Therapy Against Radical Treatment - will resolve one of the thorniest dilemmas in prostate cancer care.
"It's answering some questions that we really need some answers to. Does active treatment at the time of diagnosis really make a difference in terms of long-term survival from prostate cancer?" explained Heather Logan, director of cancer control policy with the Canadian Cancer Society.
Prostate cancer is the most commonly diagnosed cancer in Canadian men and the third most fatal form of the disease. The cancer society estimates that this year 22,300 Canadian men will be diagnosed with prostate cancer and 4,300 will die from it.
The study is designed to follow 2,100 newly diagnosed volunteers in Canada, the United States and Britain, randomly assigning them to receive either treatment or to undergo active surveillance. Men in the surveillance group whose cancer progresses or who later decide they want to have treatment can do so.
It's expected it will take four to five years to enrol all the patients who will then be followed for between 10 to 15 years. It could be 20 years before this trial produces the answer so many men and their physicians would like to see.
The principal investigator is Dr. Laurence Klotz, who daily sits across from men faced with the decision of whether to agree to a watch-and-wait approach - called active surveillance or watchful waiting - or to instead have their prostate removed or undergo radiation treatment.
On the one hand is the stress of not trying to eradicate the cancer. On the other is the real chance of long-term side-effects that can have a serious impact on the man's quality of life.
"You elect to avoid risk of prostate cancer death by having treatment, you incur very major risk of erectile dysfunction, urinary incontinence, rectal problems if you have radiation and so on," said Klotz, chief urologist at Toronto's Sunnybrook Health Sciences Centre.
"The idea is we're trying to kind of drive a middle road between treating everybody, which will result in over-treatment, and treating nobody which will result in under-treatment and just identify the ones who look like the bad actors."
He said choosing to take no immediate action is a particularly difficult one, running counter to what he calls society's "cancer hysteria" - the equation of a cancer diagnosis with a death sentence.
Tom LePoidevin, 73, had to make that tough choice in Klotz's office 16 years ago, when a PSA (prostate specific antigen) screening test revealed he had prostate cancer.
"As soon as you hear the news I think the majority of people would say: 'Oh, when are you going to be operated on,"' said LePoidevin, a retired marketing executive from Collingwood, Ont.
While he admits he occasionally frets about the fact he has a cancer he hasn't tried to excise, LePoidevin believes he has made the right choice for himself. But he hopes men in his position in future will be armed with science, not best guesses, when they have to make the same decision.
Many men with prostate cancer need to undergo treatment to stop the advance of the disease. But in many others - perhaps as many as half the cases that come to light - doctors know the cancer is unlikely to break out of the prostate and spread to other parts of the body.
Since the advent of PSA testing, large numbers of men who were seemingly healthy have been told they have cancer cells in their prostates and have faced this difficult choice. Experts say a significant portion of these men will die from other causes and would never require any prostate cancer care if the screening test hadn't signalled the presence of malignant cells.
"With a disease like this which typically is diagnosed in either late middle age or more, death from other causes is by far the commonest cause of death in men with prostate cancer. Heart disease is the commonest cause of death in men with prostate cancer," Klotz said.
He noted that at age 50, about one out of every two men will have some cancer cells in their prostate. By age 80, the number is 80 per cent.
The problem is, doctors don't know how to determine with certainty which are the cancers that will progress (and therefore should be treated) and which are the types that won't. As as result, many men receive treatment they would never have needed if their cancer hadn't been picked up by a PSA test.
"I think there's a strong consensus, not only in the United States but around the world, that there is over-treatment," said Dr. Barnett Kramer, associate director for disease prevention at the U.S. National Institutes of Health in Bethesda, Md.
"The magnitude of over-treatment is probably debated, but not the fact that some men are over-treated."
Finding a way to be able to determine at the time of diagnosis which is which would be a valuable contribution to the field of cancer care, Kramer suggested.
"Absolutely. Because day in and day out the decision is being made with regard to therapy of screen-detected prostate cancer whether to treat or how aggressively to treat," he said.
"And it affects over 100,000 men a year just in the United States, and around the world it affects that many more. And so it's not an unusual question that a patient faces and their physicians face."
