Get screened. It could save your life. Don’t get screened. There’s no evidence that screening saves lives.

Get tested in your 40s. Wait until you’re 55.

Get the test every year. Every four years is enough.

When it comes to screening for prostate cancer, the messages from doctors, major medical organizations and media campaigns are all over the map.

While not a new rift among the medical community, the prostate cancer screening debate has recently reignited. Healthy Debate looks at the evidence and ethics behind the mixed messages.

The evidence for and against PSA screening

The biggest and most trusted trial on prostate cancer screening began in 1993 and has since followed around 163,000 men in eight European countries. Around half of these men were randomly assigned to get screened every two to four years, depending on the country, while the other half weren’t screened. Most of the men were above 55 at the time of enrollment.

After 13 years of following these men, the researchers concluded that there was a benefit to routine screening. It prevented one prostate cancer death for every 781 men who were screened. The study did not find that those screened lived longer, overall, than those in the non-screening group.

On the flip side, the researchers also documented harms of screening. For every one life saved from prostate cancer death, 200-plus were found to have an elevated PSA, and a biopsy was ordered to check if prostate cancer was the reason. Out of this group, 27 men were diagnosed with prostate cancer that wouldn’t have caused illness or death, according to the European researchers. Most prostate cancers are very slow growing and never move outside of the prostate. The number of “over-diagnoses” was arrived at by comparing rates of diagnosed prostate cancer in the screening group versus the non-screened group.

The unnecessary blood tests, biopsies and potentially unnecessary treatments can be harmful – leading to anxiety or damaging physical effects. Let’s start with the PSA test itself. While not dangerous (aside from some minor bruising), it can cause anxiety as some men might worry about the results of a PSA test. Then there’s the biopsy for those found to have a high PSA. According to Girish Kulkarni, a urologist with Toronto’s University Health Network, it’s estimated 2% to 4% of men will end up in the hospital due to an infection from the biopsy needle being inserted repeatedly into the prostate through the rectum. In very rare cases, an infection from a biopsy can lead to death.

If a prostate cancer is found, there’s the risk of unnecessary treatment. Doctors have gotten better at identifying high risk cancers that must be treated and the more common ones that can be watched. But men still get treated unnecessarily, because doctors can’t always be sure whether a prostate cancer will be aggressive, and therefore err on the side of treating. This means either surgery or radiation, both of which can cause incontinence and impotence as well as other complications. Sometimes, it’s the patients that demand treatment. The anxiety of knowing about a cancer causes 10% of low-risk patients to choose to treat it even though their doctors recommend simply monitoring it, according to recent studies.

It’s important to keep in mind that the benefits of PSA screening may be larger for men with a family history of or genetic risk factors for aggressive prostate cancer, but not enough research has been done on this particular population to prove or dispute this theory.

In summary, for a small number of people, PSA testing will mean they avoid death from prostate cancer. For many others, PSA testing will lead to more tests, more anxiety, and complications from tests and treatments. “Some people will focus on the benefits side and other people focus on the harms side,” explains Neil Bell, a family physician and chair of the prostate cancer screening working group of the Canadian Task Force on Preventive Health Care. “You have to consider patient preferences and values.”

The Task Force has a ‘weak recommendation’ against PSA screening for men 55 to 69, which means the reviewers concluded the harms outweigh the benefits, but only slightly. Other organizations, like the Canadian Urology Association, recommend that prostate cancer screening “be offered to all men 50 years of age with at least a 10-year life expectancy.” Some organizations, like Prostate Cancer Canada, even recommend PSA testing to men in their 40s and 70s, though most experts say the existing evidence doesn’t support PSA screening for these age groups.

Are men being adequately informed on the risks and benefits of PSA screening?

Despite divergent opinions on the utility of testing, there is generally consensus on this point: before patients go for PSA testing, they should be informed of the risks and the benefits.

In reality, this doesn’t always happen.

The conversations we had with doctors and patients reveal that some doctors automatically send men in their 50s for PSA blood tests, without counselling them on risks. Others don’t bother with PSA testing unless the patient brings it up (in which case they discuss the pros and cons before referring a patient for the test). And others talk to every male (usually those 50 or above) about the risks and benefits and let the patient decide. “Many physicians are choosing not to have the discussion,” agrees Bell, but because no study has examined Canadian physician practices around PSA testing, we don’t know how often the risks and benefits conversations are skipped.

If patients aren’t getting information from their family doctors, they may be hearing messaging from other health organizations – at least on the benefits side. In Alberta, the “Man Van,” a service funded by the Prostate Cancer Centre at Rockyview General Hospital in Calgary, offers free PSA tests on site at workplaces, events and public places. With a logo stating ‘Get Checked’ The Man Van goes out a few times a week and draws blood to send for PSA levels of 55 men within three hours. Linda McNaughton, director of community and strategic initiatives, says Man Van employees counsel men to explain a high PSA does not mean prostate cancer. However, the men aren’t informed of the very small benefit (that 781 men need to be screened to prevent one prostate cancer death, according to the European trial) nor are they informed of the harms of testing – the risks involved with further testing and treatment. “We don’t go that far…we’re just doing awareness,” explains McNaughton.

Likewise, Prostate Cancer Canada spreads messages like “early detection saves lives, especially when it comes to prostate cancer,” but fails to mention any of the risks of screening in its press releases or video. (The organization’s website does briefly mention some “limitations” of the PSA test on its website, including “unnecessary tests and treatment,” but the harms of those tests and treatments aren’t described.)

The two organizations also tend to focus on individual stories of men, rather than the evidence on the harms and benefits – leaving patients with potentially distorted views. For instance, Prostate Cancer Canada’s website features a video where a man in his 40s is tested and is reassured to know his PSA is in the normal range. McNaughton also justifies her organization’s screening push by talking about their patients’ stories, rather than studies. “We see guys who have advanced prostate cancer because their family doctor heard that you shouldn’t be testing them,” she says. “All they can do is take hormonal treatment until they die. It’s in their bones…it’s a nasty cancer.”

Paul Glazsiou, a general practitioner and professor of evidence-based medicine in Queensland, Australia, thinks such stories are used with good intentions. People who treat or represent patients with prostate cancer want to believe that screening could prevent the kind of suffering they see, he explains, even though the trials show “most of the deaths from prostate cancer still occur, even with screening.”

Meanwhile, people like McIntyre and Edmonds routinely encounter patients who claim their lives were saved because of PSA testing – because it’s a common belief among patients that all cancers are deadly. But men often don’t share details of negative side effects. “Someone might say ‘I had prostate cancer five years ago and it was treated and now I’m running marathons,’” explains Ian Tannock, who recently retired as a medical oncologist and researcher at Princess Margaret Hospital. “You don’t hear about the men who can’t have sex and are leaking in their pants,” he says. Tannock argues doctors have an obligation to inform patients on the basis of high-quality evidence, not potentially unrepresentative stories of the individual patients they see.

Shared decision making works in theory, but what about practice?

PSA screening conversations are incredibly complex, which partly explains why some doctors aren’t having these conversations and why prostate treatment groups choose to focus on patient stories over data.

“Having the conversation around harms and benefits requires discussing complicated statistics, which nobody likes to do,” says Ben Addleman, a family physician in Calgary. Addleman does have these conversations with his patients, but they’re time consuming, often stretching beyond 10 minutes.

Dr. Bruce Topp, a family doctor in Toronto, says he tends to send men in their 50s and 60s for PSA testing because he thinks it’s beneficial, especially in light of improved diagnostic practices that reduce the risk of unnecessarily being treated. He will occasionally have conversations with patients on the harms and benefits, if a patient has questions, for example. Generally, however, he finds patients find the information too difficult to digest and don’t want the choice. “Most of the time, they say, ‘You do what you think is best.’”

Glasziou does the opposite; he doesn’t routinely screen patients, and doesn’t mention screening unless his patients ask about it. “I have a few minutes to discuss any preventative procedures, and the number one priority is going to be smoking,” he says. Because deaths from prostate cancer are relatively rare, “prostate screening is a long way down that list.”

Glasziou wonders if counselling on PSA is even possible during a doctor’s appointment. He was involved with a study in which 11 men were educated on the pros and cons of PSA screening and then asked about their opinion on screening policies. “It took them the full two days to really grapple with all of the issues,” he says. (They ultimately concluded the government shouldn’t fund PSA screening campaigns but should pay for counselling regarding the test.)

To reduce the time burden, some doctors are choosing to direct patients to websites, videos and pamphlets about PSA screening pros and cons that they can read on their own time.

Michael Barry, a Boston-based family doctor and chief science officer of Healthwise, argues doctors have an ethical obligation to offer PSA testing and counsel patients, whether through a conversation or take-home resources. That’s because some men will want the test and some men won’t – based on the same information. His research saw over 1,000 men educated via a decision aid on PSA screening. Out of those who understood the information correctly “about two thirds of them don’t want a PSA and a third of them do.”