Prostate cancer screening: massive study gets minimal coverage. Why?

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Michael Joyce is a writer-producer with and tweets as @mlmjoyce

The largest-ever randomized trial of using the prostate-specific antigen (PSA) test in asymptomatic men over the age of 50 has found — after about 10 years of follow-up — no significant difference in prostate cancer deaths among men who were screened with a single (“one-off”) PSA test, and those who weren’t screened.

The findings come from a British study called CAP (“Cluster Randomized Trial of PSA Testing for Prostate Cancer”) published earlier this week in JAMA.

Two things caught our attention here.

First, that this “largest-ever” trial did not get large coverage in the mainstream press. In fact, none of the nearly two dozen US news outlets that we check every weekday wrote about it.

Second, it reminded us that even when coverage of screening is actually large, it often falls short in two very important ways.

Study findings

Here’s what the researchers reported:

  • The cohort included 400,000 men without prostate symptoms, ages 50-69, enrolled at nearly 600 doctors’ offices across England
  • 189,386 men had a one-off PSA test vs 219,439 men who had no screening
  • After ~ 10 years:  4.3% of the screened group was diagnosed with prostate cancer vs 3.6% of the unscreened (control) group (authors attribute most of this difference to low-grade, non-aggressive cancers)
  • Despite finding more cancer in the screened group, the authors found both groups had the same percentage of men dying from prostate cancer, and that percentage was very low: 0.29%

Small coverage of a large study

As of our publishing this article — two days after the British study was published — coverage of this “largest-ever” trial remains scant. Is it because it’s a European study? Unlikely — the results were featured prominently in one of the most prestigious US medical journals and promoted with an embargoed news release. Or, because it represents a so-called ‘negative’ or non-dramatic finding? (That is, no increase in prostate cancer deaths between the two groups found.) Who knows.

But it stands in stark contrast to the mega-coverage we’ve documented for many years on other prostate cancer screening studies that are typically much less rigorous — and which often trumpet an imbalanced, pro-screening message about prostate cancer. Not that the British study advocates against screening, but it certainly brings many of its limitations into focus.

Kenny Lin MD, a professor of family medicine at Georgetown University, was shocked that such a large study as the CAP got so little coverage. He agrees that whether a study’s results support more screening, or less screening, may have something to do with it:

Kenny Lin, MD

Kenny Lin, MD

“I’m amazed! Last fall there was this reanalysis of old data published in the Annals of Internal Medicine. The results supported more screening, and the mainstream news coverage was extensive. There were plenty of headlines like the LA times touting ‘prostate cancer screening saves lives after all’ (also, NYTCBS News). Yet this CAP trial — involving 400,000 actual patients, rather than simply being an extrapolation from old data — has had virtually no coverage. And certainly no headlines stating ‘PSA screening didn’t save lives.’

“I think that journalists ought to prioritize coverage based on the quality of the study, not the perceived newsworthiness of the conclusion.”

Here are some examples of how perceived news-worthiness influences coverage of prostate cancer screening.

Every September — Prostate Cancer Awareness Month — we’re flooded with news coverage promoting mass/free PSA screenings. The intense coverage is very often fawning but rarely mentions that several reputable medical organizations don’t support such indiscriminate screenings.

And when celebrities promote screening — whether it be TV docs or the NFL — the coverage is inevitably brisk, but usually fails to bring up important considerations of over-diagnosis, over-treatment, and complications.

Two simple ways to improve coverage of cancer screening

First, every story about screening needs to, at the very least, let readers know about the limitations of the screening method. What are the pros and cons of the test? Another way to approach this is simply asking physicians “what are the benefits and risks involved in this screening tool?”

It also helps to anticipate the questions patients might ask. Questions like: “How much can I trust a positive or negative result? (false positives/negatives) … if the test is negative, then what? … if the test is positive, what costs or risks am I exposed to if we evaluate further?” The latter are often called “downstream consequences,” and they can be significant.

In short, questions that matter to patients should matter to journalists.

Second, most cancers are nuanced diseases that exist along a spectrum of severity or aggressiveness. News coverage like that we link to above — which tends to be promotional, fear-mongering, or downright coercive — completely ignores one of the most important principles of screening. That is, the decision to get screened or not depends on a balance of benefits and risks, and how much importance the individual places on those specific benefits and risks. It is not the simple yes-or-no proposition it may appear to be. And reporters should not portray it as such.

Just as cancer is nuanced and individual, the decision to screen for it is also nuanced and individual. It requires guidance. That guidance should be balanced and complete and should involve the participation of your doctor.

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Comments (4)

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Richard J. Ablin

March 9, 2018 at 9:12 am

After publication of my Opinion Editorial “The Great Prostate Mistake” in The New York Times (10 March 2010 [}) I was interviewed by Victoria Lambert, Daily Mail, for a 4 May 2010 article “Why Men Shouldn’t Rely on the Prostate Cancer Test” which describes a similar outcome to the conclusions 8 years later by the “CAP Randomized Clinical Trial”. My 2014 book with Ron Piana, “The Great Prostate Hoax: How Big Medicine Hijacked the PSA Test and Caused a Public Health Disaster” (Palgrave Macmillan, NY) further documented the uselessness of the PSA test for screening men with prostate cancer. The question I put to those who continue to try to promote the PSA test for screening: What has been accomplished in the last eight years save for the continued overdiagnosis and overtreatment of men and their decreased quality of life?

rob oliver md

March 12, 2018 at 8:46 am

Concluding that there’s no benefit in that group is only true if mortality is one your one and only endpoint and morbidity of treatment is ignored. Much like the discussion on mammograms, early treatments of disease can be significantly less morbid and convenient to the patient despite not showing up in mortality benefit. It doesn’t diminish the importance of this kind of study, but it’s a common oversight in pure actuarial assessments of screening tests

James S Thornton

March 12, 2018 at 10:29 am

Two notes:
1) Dr. Ablin may be too modest to point this out, but he is the researcher who first discovered PSA in 1970, which, in my mind, gives his cautionary words even more weight.
2) Dr. Oliver raises a good point about mortality vs. morbidity. However, this needs to be applied to all men treated–some necessarily, the vast majority not–for prostate cancer. According to some estimates, 1.4 million American men are today walking around without their prostate glands after having been “treated” for a disease that would not have impacted the vast majority of them in any way. Of these 1.4 million men, how many suffer from incontinence and erectile dysfunction as a result of their over treatment? What about the (admittedly much smaller) number of men in whom PSA testing suggested the need for needle biopsies, which in turn introduced pathogens into their blood streams when the needles crossed the rectal wall? The latter has, in fact, caused deaths in men in whom no PC was ultimately discovered. That cannot be an easy discussion for the prescribing physician with surviving family members. “The good news? We found ZERO trace of prostate cancer! The bad news? Your loved one died from a massive systemic infection from antibiotic-resistant bacteria inadvertently transferred from his rectum to his bloodstream.”

Chris O'Neill

March 13, 2018 at 9:30 am

“the decision to get screened or not depends on a balance of benefits and risks, and how much importance the individual places on those specific benefits and risks”

The reality with PSA screening is even worse than that common perception. Specific benefits have never been proven generally, not even for disease specific mortality. Not proven generally because the results of trials in 2 countries do not automatically flow to other countries, not even if the ERSPC says they do because they couldn’t prove they don’t. The ERSPC failed Statistical Inference 101: failure to reject a null hypothesis (of homogeneity in this case) does not prove a null hypothesis.