99% of men survive early prostate cancer, even if they skip treatment: study
Jeff Lagerquist, CTVNews.ca Staff
Published Wednesday, September 14, 2016 10:01PM EDT
There are three options for men diagnosed with prostate cancer: the scalpel, radiation, or the hands-off approach. It’s a difficult decision, and experts have consistently said there is no right answer.
However, a new British-based study published Wednesday in the New England Journal of Medicine suggests it may not matter which you choose since the risk of dying after 10 years is the same -- about one per cent.
“There’s been no hard evidence that treating early disease makes a difference,” said the study’s chief investigator Dr. Freddie Hamdy of the University of Oxford in an interview with The Associated Press.
Prostate Cancer is the most common form of the disease among Canadian men, according to the Canadian Cancer Society, representing 24 per cent of all new cases in 2015.
However, its high survival rate leaves many confused about how to approach treatment. Surgeons have long argued with radiologists about with proactive approach is most effective, but there is growing support for simply monitoring the disease in its early stage, since growth tends to be very slow and prostates naturally enlarge as men grow older.
“Our aggressive approach to screening and treating has resulted in more than one million American men getting needless treatment,” said Dr. Otis Brawley, chief medical officer for the American Cancer Society in an interview with AP.
He was not involved with the study, but welcomes the results, noting that the utter shock of a cancer diagnosis often pushes people towards the most intrusive treatments.
“It’s a challenging process to explain to people that certain cancers just don’t need to be treated,” he said.
The study involved more than 8,200 men in the United Kingdom between 50 and 69 who were tested for prostate specific antigen. High level can be a red flag for prostate cancer, but can also signal natural growth with age.
Of the men diagnosed with early prostate cancer, 1,643 agreed to be randomly assigned surgery, radiation, or active monitoring.
Those who chose the active monitoring approach had their blood tested every three to six months, spoke with councillors, and discussed switching to proactive treatment if their condition worsened.
Researchers found the rate of survival was consistent across all three groups -- 99 per cent. However, more men in the active monitoring group saw their cancers worsen -- 112 versus 46 given surgery and 46 given radiation. Radiation and surgery yielded significant side effects, especially urinary, bowel or sexual problems.
The study’s authors were careful to caution that their findings can only be applied to 10 years after a patient’s initial diagnosis. Meaning, differences in survival rates could emerge after 15 years or 20 years for example.
While the British study, which was paid for by the country’s National Institute for Health Research, has proven that large scale randomized treatment trails can be achieved, the finding are still highly controversial.
Doctors Christopher Wallis and Robert Nam of the University of Toronto published a rebuttal Wednesday, saying the findings of the British study “raise more questions than answers” and the methodology was “clearly underpowered to evaluate the primary outcome of prostate-cancer specific mortality.”
“The conclusions of the primary analysis are based on a total of 17 (17!!) deaths,” wrote Wallis and Nam.
They also note that 77 per cent of the men tested had a Gleason score of six, indicating low-grade prostate cancer better suited to active surveillance rather than active therapy.
“Clinically meaningful decisions between surgery and radiotherapy are in the realm of treatment of intermediate and high-risk localized prostate cancer and these comprise a small group in this study,” said the U of T doctors.
Wallis and Nam conclude this means the vast majority of those tested were unlikely to experience major prostate growth when they were tested after a decade.
They also point out the British study proves the effectiveness of radiation and surgery since the findings reveal “significantly higher rates of progression, metastasis, and prostate cancer specific mortality for patients treated on the surveillance program as compared to those treated actively.”