PSA screening: Benefit does not outweigh harm
Some men benefit from an earlier cancer diagnosis; however, more men are at risk of overdiagnosis and treatment-related complications; studies have yet to show whether a risk-adapted approach will affect this conclusion
The benefit of population-based PSA screening for men with an average risk of prostate cancer does not outweigh the harm caused. This is the conclusion drawn by the Institute for Quality and Efficiency in Health Care (IQWiG) in its final report after evaluating the worldwide evidence from studies on the topic. While screening using a PSA test benefits some men by preventing or delaying metastatic prostate cancer, at the same time, however, considerably more men are at risk to become permanently incontinent or impotent due to overdiagnosis and subsequent overtreatment – and this at a relatively young age.
At the hearing on the preliminary report, IQWiG discussed in detail with participants whether and how the harm from PSA screening could be reduced using risk-adapted screening strategies without simultaneously reducing the benefit. IQWiG’s Director Jürgen Windeler emphasizes “Measures such as restricting biopsies to men at high risk of progression or using new biopsy methods are promising approaches to improve the benefit-harm ratio of PSA screening in the long term. However, there are currently no studies to prove this.” Therefore, the overall assessment of PSA screening remained unchanged in IQWiG’s final report.
The most common type of cancer in men
Prostate cancer is the most common cancer in men in Germany, accounting for 23 percent of all new cancer cases and causing approximately 14,000 deaths per year.
The aim of screening is to detect prostate cancer with a high risk of progression at an early stage in order to cure the disease. Two screening tests are currently used: the digital-rectal examination and the test for prostate-specific antigen (PSA). The former is part of the screening programme offered by statutory health insurance for men aged 45 and older, the PSA test is not.
The IQWiG benefit assessment now available is based on the analysis of 11 randomized controlled trials with more than 400,000 participants worldwide. All of these studies compare prostate cancer screening using the PSA test with no screening for prostate cancer.
More harm than benefit in the overall balance
After evaluating the evidence, IQWiG concludes that prostate cancer screening using a PSA test benefits some men with prostate cancer by delaying or preventing metastatic cancer. This advantage only occurs after several years. Moreover, it is unclear whether screening leads to an increase in overall life expectancy in these men.
At the same time, PSA screening harms overdiagnosed men (men with prostate cancer not requiring treatment) and men with a false-positive screening test result (men without prostate cancer). The overdiagnosed men are at risk of treatment-related complications such as incontinence and impotence. Men with a false-positive result may experience harm in the form of a worrying test result that is followed by a prostate biopsy.
Overall, prostate cancer screening using a PSA test harms considerably more men through overdiagnosis than it benefits men through earlier diagnosis of the cancer. In summary, on the basis of the available studies IQWiG therefore concludes that the benefit of PSA screening does not outweigh the harm. The Institute is in good company with this careful consideration: worldwide, almost all national health authorities and professional societies recommend against population-based PSA screening.
Process of report production
The project “Prostate cancer screening using a PSA test” was commissioned to IQWiG by the Federal Joint Committee (G-BA) at the request of patient representatives. IQWiG published the preliminary results on this project, the so-called preliminary report, in January 2020 and invited comments for discussion. After the commenting procedure, the preliminary report was revised and, among other things, a section on “Measures to reduce harm from screening” was added. IQWiG sent the final project report to the G-BA in April 2020. The written comments submitted were published in a separate document at the same time as the final report.
An English extract of this report will be available soon. If you would like to be informed when it is published, please contact [email protected]