MRI scans could improve prostate cancer screening accuracy
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There is good news and bad news when it comes to prostate cancer screening. First the bad news: The blood test in question measures a compound called prostate-specific antigen (PSA), but it’s too inaccurate. As a result, some men end up receiving cancer treatments they don’t really need, which can lead to urinary incontinence and erectile dysfunction.
On the other hand, combining a PSA test with a prostate MRI scan would make screening more accurate, especially if dual testing is only recommended for people at high risk for tumors. A panel of experts from the Lancet Commission on Prostate Cancer made this recommendation in a new report.
There is a real need to rethink prostate screening, but will these new proposals succeed in reducing harm?
Prostate screening has long been controversial. Although cancerous prostate cells release high levels of PSA, healthy cells also produce lower levels of PSA.
Blood tests were introduced as a way to track the success of cancer treatments. It began being used as a screening test in the 1990s, in part because men’s health groups campaigned for a test similar to breast cancer screening.
The problem is that PSA itself is not a reliable screening tool. Levels may be temporarily elevated after sex, during a urinary tract infection, or even while riding a bicycle. Even if this rise persists, most prostate cancers grow so slowly that if left unchecked, they will never be noticed or cause any problems.
These issues would be less important if not for the fact that treatments to remove the cancer (usually surgery or placing radioactive particles into the tumor) often result in permanent incontinence or erectile dysfunction. Even having a biopsy to determine if cancer is present can cause these problems.
randomized trial Research shows that for every 1,000 men who undergo regular PSA screening, one fewer man will die from prostate cancer over 10 years, but three men will develop urinary incontinence and 25 men will develop impotence.
These disturbing figures leave health services facing uncomfortable compromises in most high-income countries, including the UK and Australia. Unlike breast or bowel cancer tests, they do not send invitations for prostate screening, but people who request it can get tested if the risks are explained.
As a result, men with higher incomes received PSA tests more often, while men with lower incomes or black men received PSA tests less often, the new report said. This is unfortunate because men of African descent are twice as likely to develop prostate cancer as men of European descent.
The report’s authors said health systems should use more sophisticated forms of screening, including PSA tests and MRI scans. With a scan, your doctor can assess the size of your prostate and find any suspicious areas that may indicate cancer.
In some countries, including the UK, something approaching this dual approach is already happening, as the next step for anyone found to have high PSA levels is to get an MRI scan. This means those with reassuring scan results can avoid a more invasive biopsy. “This greatly alleviates the problem of overdiagnosis,” said Nicholas James One of the report’s authors is from the Institute of Cancer Research, London.
But James said it might be better to combine the PSA test with an MRI scan before any results are returned, to avoid men being incorrectly told they may have cancer.
The committee said health services should start formal screening campaigns using this combined approach but targeting three groups known to be at higher risk.These people are: black men, anyone with a family history of prostate cancer, and men with one of the gene mutations breast cancer genes, which are also linked to breast cancer.
This would avoid the current situation where men with lower risk levels may receive too many PSA tests, while men with higher risk levels receive fewer or no tests.
These recommendations are certainly thought-provoking, but whether they will dampen interest in prostate screening remains to be seen. David Ropeik, an American author who recently wrote a book called “The Annual Men’s Health Checkup,” said some U.S. doctors have gone further than current recommendations by testing the data collected during men’s annual health checkups. The blood was tested for PSA without even a discussion with the individual involved. Cure cancer phobia.
James said the arrival of the PSA test could be like the opening of Pandora’s box, but with the new methods being proposed, at least some of the harm might be reduced.
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