Prostate cancer ranks as the second most common cancer among men worldwide. The debate over early detection through screening has persisted for years, with experts divided on whether the benefits outweigh the risks of overdiagnosis and overtreatment. A new Cochrane review now provides updated evidence that screening for prostate cancer using a blood test can likely reduce the risk of dying from the disease. This marks a significant shift from the previous review, which found insufficient evidence to support a reduction in prostate cancer deaths. The findings have been published in the Cochrane Database of Systematic Reviews.
A Modest but Meaningful Benefit
In the review, researchers analyzed six trials involving 800,000 participants across Europe and North America. They discovered that screening with the PSA (prostate-specific antigen) blood test reduces prostate cancer deaths by approximately 2 for every 1,000 men screened. This translates to one prostate cancer death prevented for every 500 men screened. These mortality figures are derived from a major trial that followed 162,241 men for 23 years.
Dr. Philipp Dahm, senior author from the University of Minnesota, stated in a release: "With new data now available, we can now say with moderate certainty that PSA screening reduces prostate cancer deaths in men with a sufficient life expectancy. This suggests that for the right patient – someone who is well informed, has a good life expectancy, and understands the full implications of screening – there is now a reasonable evidence base to support a conversation about PSA screening. This represents an important change in the evidence for future guideline developers and policy-makers to consider."
However, the studies in the review did not assess the impacts on quality of life, such as complications from biopsies, sexual dysfunction, and urinary problems.
Risk of Overdiagnosis
While the PSA blood test for prostate cancer screening can make a meaningful difference, the risk of overdiagnosis remains. The screening detected about 30% more prostate cancers overall, at an early stage. Roughly 36 extra cancers were diagnosed per thousand men screened, for every 1–2 deaths prevented. These tests can detect low-grade cancers that may never have caused symptoms or harm during a man's lifetime. Such identification can lead to anxiety and unnecessarily aggressive treatment.
First author Dr. Juan Franco from Heinrich Heine University Düsseldorf emphasized: "We want to be clear that this is not a blanket endorsement of universal screening. The decision should always be made between a patient and their doctor, with a full understanding of both the potential benefits and the very real risks of overdiagnosis and unnecessary treatment."
Better Data, Stronger Evidence
The previous version of this review found that screening did not significantly reduce prostate cancer deaths. It was based on a meta-analysis of five randomized controlled trials. This uncertainty led to delays in, or the avoidance of, the introduction of national screening programs in several countries.
The authors of this review emphasized that the modest benefits now observed are not due to a change in the underlying evidence, but because the trials have now followed participants for long enough to detect a mortality benefit that was previously too early to observe. Dr. Franco added: "The landscape has changed considerably since our 2013 review. Not only do we have stronger long-term evidence on mortality, but the tools available to reduce the harms of screening, such as MRI and active surveillance, have also advanced significantly."
This review also examined new screening approaches, such as combining PSA tests, kallikrein blood tests, and MRI scans, to improve accuracy. This approach also reduces unnecessary biopsies. MRI and active surveillance methods help detect low-risk cancers that do not require aggressive treatment. For patients and doctors considering prostate cancer screening, the evidence now supports an informed discussion. However, this should remain individualized, weighing both the modest mortality benefits and the very real risks of overdiagnosis and unnecessary treatment.
