Most men who are diagnosed with prostate cancer can delay or avoid aggressive treatments without harming their chances of survival, show new results from a long-term UK study.
Men in the study who, in partnership with their doctors, closely monitored their low- and medium-risk prostate tumors — a strategy called active or watchful monitoring — reduced their risk of life-changing complications, such as incontinence and erectile dysfunction that can arise following aggressive treatment for the disease, but were no more likely to die from their cancers than men who had surgery to remove the prostate or who were treated with hormone blockers and radiation.
“The good news is that if you are diagnosed with prostate cancer, don’t panic, and take your time to make a decision” about how to proceed, says study lead author Freddie Hamdy, professor of Surgery and Urology at the University of from Oxford.
Other experts who were not involved in the research agreed that the study was reassuring for men diagnosed with prostate cancer and their doctors.
“When men are carefully evaluated and their risk analyzed, it is possible to delay or avoid treatment without missing the opportunity for a cure in a large proportion of patients,” says Bruce Trock, professor of Urology, Epidemiology and Oncology at Johns Hopkins University.
The results do not apply to men who have prostate cancers that are assessed to be high risk and advanced. These aggressive cancers, which account for about 15% of all prostate cancer diagnoses, still need immediate treatment, says Hamdy.
For others, however, the study adds to a growing body of evidence showing that surveillance of prostate cancers is often the right thing to do.
“What I take away from this is the safety of actively monitoring patients,” says Samuel Haywood, a urological oncologist at the Cleveland Clinic in Ohio, who reviewed the study but was not involved in the investigation.
The results of the study were presented at the annual conference of the European Association of Urology in Milan, Italy. Two studies of the data were also published in the New England Journal of Medicine and a companion journal, NEJM Evidence.
A common cancer that is often low-risk
Prostate cancer is the second most common cancer in men in the United States, behind non-melanoma skin cancers. About 11% – or 1 in 9 – of American men will be diagnosed with prostate cancer during their lifetime, and overall, about 2.5% – or 1 in 41 – will die from it, according to the National Institute of Cancer. North American cancer. About $10 billion is spent annually on treating prostate cancer in the US.
Most prostate cancers grow very slowly. It usually takes at least 10 years for a tumor confined to the prostate to cause significant symptoms.
The study, which has been running for more than two decades, confirms what many doctors and researchers have since come to realize: most prostate cancers identified by blood tests that measure levels of a protein called prostate-specific antigen, or PSA will not harm men during their lifetime and does not require treatment.
Oliver Sartor, medical director of the Tulane Cancer Center, says men should understand that much has changed over time, and that doctors have refined their approach to diagnosis since the study began in 1999.
“I wanted to make it clear that the way these patients are screened, biopsied and randomized is very, very different from the way these same patients might be screened, biopsied and randomized today,” says Sartor, who wrote an editorial about the study, but was not involved in the investigation.
He says the men included in the study were in the early stages of their cancer and were mostly low risk.
Now, he says, doctors have more tools, including MRI imaging and genetic testing that can help guide treatment and minimize overdiagnosis.
The study authors say that to allay concerns that their results might not be relevant to people today, they reassessed their patients using modern methods of grading prostate cancers. By those standards, about a third of his patients would have an intermediate or high-risk disease, something that didn’t change the conclusions.
When less treatment results in better care
When the study began in 1999, routine PSA screening in men was the norm. Many physicians encouraged annual PSA testing for their male patients over age 50.
PSA tests are sensitive but not specific. Cancer can raise PSA levels, but so can things like infections, sexual activity, and even cycling. Tests with elevated PSA levels require other tests, which may include imaging and biopsies to determine the cause. Most of the time, this whole procedure just isn’t worth it.
“In general, it’s thought that only about 30% of people with an elevated PSA actually have cancer, and among those who do have cancer, the majority don’t need to be treated,” says Sartor.
Over the years, studies and models have shown that using regular PSA tests to screen for prostate cancer can do more harm than good.
By some estimates, as many as 84% of men with prostate cancer identified through routine screening do not benefit from detection of their cancers because they would not be fatal before dying of other causes.
Other studies have estimated that one to two out of five men diagnosed with prostate cancer receive overtreatment. The harms of prostate cancer overtreatment are well documented and include incontinence, erectile dysfunction and loss of sexual potency, as well as anxiety and depression.
In 2012, the influential US Preventive Services task force advised otherwise healthy men not to have PSA tests as part of their routine checkups, saying the harms of screening outweighed the benefits.
Now, the working group opts for a more individualized approach, saying men between the ages of 55 and 69 should decide whether to undergo periodic PSA testing after carefully weighing the risks and benefits with their doctor. And they advise against PSA-based screening for men over 70 years of age.
The American Cancer Society supports much the same approach, recommending that men of average risk have a conversation with their doctor about the risks and benefits starting at age 50.
Treatment had no impact on survival.
The trial followed more than 1,600 men who were diagnosed with prostate cancer in the UK between 1999 and 2009. All of the men had cancers that had not metastasized or spread to other parts of their bodies.
When they joined, the men were randomly assigned to one of three groups: active monitoring or using regular blood tests to monitor PSA levels; radiotherapy, which used hormone blockers and radiation to shrink tumors; and prostatectomy, or surgery to remove the prostate.
Men who were assigned monitoring could switch groups during the study if their cancers progressed to the point where they needed more aggressive treatment.
Most of the men have been followed for about 15 years, and for the most recent data analysis, the investigators were able to obtain new information from 98% of the participants.
In 2020, 45 men – about 3% of participants – had died from prostate cancer. There were no relevant differences in prostate cancer deaths between the three groups.
Men in the active monitoring group were more likely to have their cancer progress and spread throughout the body compared to the other groups. About 9% of men in the active monitoring group saw their cancerous metastases grow, compared with 5% in the other two groups.
Trock points out that while it didn’t affect their overall survival, a cancer that spreads is not an insignificant outcome. It can be painful and may require aggressive treatments to manage at this stage.
Active surveillance had important advantages over surgery or radiation.
By following the men for 12 years, the researchers found that between 1 in 4 and 1 in 5 of those who had prostate surgery needed to wear at least one patch a day to protect themselves from leaking urine. That rate was twice as high as the other groups, says Jenny Donovan of the University of Bristol, who led the study of patient-reported outcomes after treatment.
Sexual function was also affected. It’s natural for men to decline with age, so by the end of the study, nearly all men reported low sexual function, but their patterns of decline were different depending on their prostate cancer treatment, he says.
“Men who have surgery have low sexual function early on, and that continues. Men in the radiotherapy group see their sexual function drop, then they have some recovery, but then their sexual function declines, and the active monitoring group slowly decreases over time,” says Donovan.
Donovan says that when she presents her data to doctors, they point out how much has changed since the study began.
“Some people would say, ‘OK, yes, but now we have all these new technologies, new treatments,'” she says, such as intensity-modulated radiotherapy, brachytherapy and robotic prostate surgery, “but actually other studies showed that the effects on these functional outcomes are very similar to the effects we see in our study,” he says.
Both Donovan and Hamby feel that the study’s findings still deserve careful thought by men and their doctors when weighing treatment decisions.
“What we hope doctors will do is take these numbers that we’ve come up with in these investigations and share them with men so that those newly diagnosed with localized prostate cancer can really weigh these advantages and disadvantages,” says Donovan.