Larry Goldenberg: Checking PSA is not stepping onto a slippery slope to inevitable biopsies
Credit to Author: Hardip Johal| Date: Sat, 16 Nov 2019 02:00:15 +0000
Too much ink and angst have been spilled in debating whether the PSA blood test should be used to screen for prostate cancer.
After 35 years in urology, I do not want to return to the pre-PSA era when men regularly hobbled into my clinic on crutches because prostate cancer had spread to their bones, who required removal of their testicles to give them a few months of relief from their pain.
The PSA has allowed us to detect cancer at an earlier stage, and it has reduced the number of men with widespread metastasis from 40 per cent to less than five per cent.
I do agree that the test is not perfect. It has false-positive and false-negative results and leads to over-diagnosing men with very early-stage cancers that we might be better off not knowing were present.
But simply checking PSA is not stepping onto a slippery slope to inevitable biopsies, surgery, radiation and chemotherapy; it is just a single decision point.
“I am fully biased in favour of PSA testing because many of my patients would be dead today if they had not had it,” writes Dr. Larry Goldenberg.
PSA screening is like a fishing expedition where the goal is to catch the large fish and toss back the small ones, which may grow over time and be caught at a later date. If a prostate cancer is caught early, and its characteristics are such that it is unlikely to grow quickly, we offer active surveillance and defer therapy unless it changes over time.
But if we catch an aggressive, life-threatening cancer at an early stage (which is common these days), we have a chance to control or even cure it. In this way, we can avoid overtreating cancers and not risk “missing the boat.”
“Experts” who recommend against PSA screening do so because they look at data and only ask one question: Does PSA screening save lives? (Indeed, the most modern and best studies suggest that the answer is: Yes.)
But this misses an important point.
Early detection is not just about preventing death, but also about reducing pain and suffering, even if these men don’t die of their cancer. This reality is not addressed in the research studies that are the basis of recommendations against screening.
So let’s not throw out the baby with the bathwater.
The PSA to a urologist is like a stethoscope to a cardiologist: simply a tool to be considered in context of the whole patient and interpreted with medical expertise.
Scientists continue to search for the “holy grail:” The test that will allow us to separate the good from the ugly without the need of a biopsy.
Until then, any harms of PSA-based screening can be minimized by good clinical practice.
Over the past decade we have learned that a very low PSA test in a man in his 40s means that he is highly unlikely to develop serious cancer during his lifetime. Annual screening is not necessary, unless he has other risk factors.
But if his level is high, then he needs to see a specialist to discuss his risks of having cancer. We call this “smart screening.”
A rational approach can avoid excess biopsies, and even those that turn out to be negative will have been worth doing for peace of mind.
So for now, we need the PSA. We need to acknowledge the subtleties of its interpretation and to discuss the implications with the patient and his partner.
So, to the anti-screeners: Stop encouraging men to bury their heads in the sand.
I am fully biased in favour of PSA testing because many of my patients would be dead today if they had not had it. Unlike many anti-screener academics, I’ve spent too much of my professional life giving people bad news when I could have given them hope.
Dr. Larry Goldenberg is professor of Urologic Sciences at UBC, chair of the Canadian Men’s Health Foundation and director of supportive care at the Vancouver Prostate Centre.
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