Rethinking the Cost-Benefit of PSA Tests

2019.09.12 Prostate_Cancer_(26454931773)

Was this Fixing U.S. Healthcare blog wrong to single out PSA as not worth its cost? This was the claim in two previous posts, including the overall most popular one, The Problem of Diminishing Marginal Benefit in Healthcare.

Some new information suggests that we need to rethink that original claim.

Prostate Specific Antigen

Since prostate cancer is the second most common cancer in men worldwide, its early detection by an immune-based blood test has been a vigorous focus of research going back to at least 1960, according to a 2007 historical review in Urology.  It took until 1986 for a commercial lab, Hybritech, Inc., to perfect the PSA test enough to earn FDA approval. PSA’s widespread adoption since the early 1990s coincided with decreases in prostate cancer deaths. PSA enthusiasts credit the test for this result. But the reality is that the picture is complicated by such factors as evolving improvements in nerve-sparing treatments, the slow-moving “natural history” of prostate cancer (interfering “quick answers” to research), and controversy over “lead-time bias” (earlier detection, but without any survival advantage).

Suffice it to say that by 2012, the U.S. Preventive Services Task Force (USPSTF) concluded that doctors were over-diagnosing so many harmless tiny cancers – and over-treating them with radical surgery and radiation – that they were actually causing more harm than good. By then, 20-year follow-up studies were showing in half of these reports no survival benefit for PSA testing and in the other half perhaps one death avoided after 10 years for every 1,400 men screened. At the same time radical treatments were causing bladder incontinence, bowel injuries, and sexual side-effects in half of patients.

Thus, USPSTF – and several like-minded medical associations – recommended in 2012 to stop PSA testing on any average patients (There was still a role for special high-risk cases and for monitoring cancer treatments).  I agreed that PSA was not worth the cost, and said so in my You Tube video and blog post.

New Developments

Since 2012, there have been several new developments:

  • Further studies have confirmed a small survival advantage: an average of 1.3 cancer deaths and 3 cancer spreads (metastases) prevented over 13 years for every 1,000 men screened.  This is slightly better than 0 or 1 estimated previously — still not very impressive, but cannot be ignored. Of note, there is a subgroup of aggressive prostate cancers that still cause death in 5 out of 1,000 men, despite screening, biopsy and definitive treatment. And overall all-cause mortality is unchanged whether we test PSA or not.
  • Up until 2010, all prostate cancers, including low-risk “Gleason 6” cases, were treated with radical prostate surgery or aggressive radiation. But since then, new research has given urologists and patients the assurance that there is nothing lost by opting for “active surveillance” instead of definitive treatment. USPSTF in 2018 estimated that 30 out of 100 men with low-risk cancer were opting out of aggressive treatment. A new study has now shown that the percent of men choosing active surveillance over surgery climbed to 42% by 2015; it’s probably higher yet by 2019.

And so in 2018, USPSTF changed its conclusion to:

The USPSTF concludes with moderate certainty that the net benefit of PSA-based screening for prostate cancer in men aged 55 to 69 years is small for some men. How each man weighs specific benefits and harms will determine whether the overall net benefit is small.

The USPSTF concludes with moderate certainty that the potential benefits of PSA-based screening for prostate cancer in men 70 years and older do not outweigh the expected harms.

USPSTF disclaims that individual decisions by individual doctors for individual patients depends on more than just this population-based research.  The mantra is, “Even if the research shows 1% risk, if it happens to this one patient it’s 100% for him.”

What About Cost?

The USPSTF clearly says, “The USPSTF does not consider the costs of providing a service in this assessment.” I have not found any published systematic cost-benefit analysis studies of PSA testing. However, mathematically if the “benefit” is so low as to approach 0, then the cost per benefit approaches infinity, not a good bargain.

What Does This Mean?

If the U.S. adopted the Oregon-style cost-benefit approach to provide all cost-worthy care and eliminate non-cost-worthy care, a reformed U.S. healthcare system would not pay for PSAs for all men starting at age 50. Instead, the healthcare system would allow men to opt in or opt out of PSA testing on a case-by-case basis. This would be done after a thoughtful discussion with each man’s personal doctor highlighting the small benefit, the not inconsiderable risks (anxiety over false positives and harms of over-treatment), as well as the man’s own preferences and fears. This is exactly the new recommendation from the USPSTF.  And it is the approach used in Great Britain by its cost-conscious National Health Service.

Conclusion

This blog was not too far off by saying PSA was a “cost with no benefit.”  In fairness, however, this blog should now say that PSA is a “cost with precious little benefit, but deserves a discussion with your doctor.”

Meanwhile, this blog’s general claims still hold:

  • Doctors, patients and the healthcare system – both in the U.S. and other developed countries – are providing testing and treatments uncritically, or, worse, responding to perverse incentives of profit (by testing companies) or fee-for-service (by urologists). See Why So Costly? and Taming the Healthcare Tapeworm
  • Americans pay twice as much for their healthcare services as patients in other developed countries to for theirs. See New Data
  • There is other waste throughout the healthcare systems of both U.S. and other developed countries
  • An Oregon-style cost-benefit approach – with other public policy input – could help reform the system
  • A political fix is needed to overcome now-solidly-entrenched habits and interests before we could undertake an Oregon-style approach. See my recent post.

Take Action

So, take action.

Disclaimer:  This information is presented for the purpose of public policy discourse.  It is not intended as medical advice. For diagnosis and treatment of any medical condition, the reader should consult a healthcare professional.

 

Image Credit

Title:  Prostate Cancer

By: National Human Genome Research Institute (NHGRI) from Bethesda, MD, USA

URL:  https://commons.wikimedia.org/wiki/File:Prostate_Cancer_(26454931773).jpg

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