PSA-based prostate cancer screening reduces mortality but increases diagnoses
This Cochrane meta-analysis synthesized evidence from six randomized controlled trials conducted in Europe and North America, involving 789,086 randomised participants. The population included men aged 45 to 80 years with no prior diagnosis of prostate cancer. The intervention was prostate cancer screening based on PSA testing, alone or with digital rectal examination, or PSA-based screening combined with kallikrein panels and MRI. The comparator was no screening or usual care without systematic PSA screening. Follow-up ranged from 3.2 to 23 years.
The primary outcomes were prostate cancer-specific mortality, overall mortality, and adverse events. For prostate cancer-specific mortality, screening likely results in a reduction (Rate Ratio 0.87; 95% CI 0.80 to 0.95; 1 study, 162,236 participants; moderate-certainty evidence). Assuming a baseline risk of 16 prostate-cancer-related deaths per 1000, this corresponds to 2 fewer deaths per 1000 (95% CI 3 fewer to 1 fewer). For overall mortality, screening may reduce mortality, but the confidence interval includes little to no effect (Rate Ratio 0.99; 95% CI 0.97 to 1.00; 4 studies, 675,121 participants; low-certainty evidence). Assuming a baseline risk of 491 deaths from any cause per 1000, this corresponds to 5 fewer deaths per 1000 (95% CI 15 fewer to 0 fewer).
For adverse events, screening may result in little to no difference (RR 1.32; 95% CI 0.48 to 3.65; 1 study, 408,721 participants; low-certainty evidence). Assuming a baseline risk of 3 deaths from any cause per 100,000, this corresponds to 1 more death per 100,000 (95% CI 2 fewer to 8 more). Screening likely increases prostate cancer diagnoses (Rate Ratio 1.30; 95% CI 1.27 to 1.34; 1 study, 162,241 participants; moderate-certainty evidence), with a minimal clinically important difference (MCID) of 10 per 1000 participants.
Key secondary outcomes showed screening likely increases localised disease diagnosis (RR 1.53; 95% CI 1.48 to 1.59; 1 study, 162,236 participants; moderate-certainty evidence) and may reduce metastatic prostate cancer diagnosis (RR 0.65; 95% CI 0.59 to 0.71; 1 study, 162,236 participants; low-certainty evidence). Screening likely has little to no effect on advanced prostate cancer diagnosis (RR 0.90; 95% CI 0.85 to 0.95; 1 study, 162,236 participants; moderate-certainty evidence). For PSA, kallikrein panel, and MRI screening versus control, screening likely has little to no effect on prostate cancer diagnosis (RR 1.85; 95% CI 1.56 to 2.19; 1 study, 60,745 participants; moderate-certainty evidence).
Safety findings indicated screening may result in little to no difference in adverse events as measured by deaths related to prostate biopsy or treatment; safety data for PSA, kallikrein panel, and MRI screening were not reported. Serious adverse events and discontinuations were not reported. Tolerability was not reported.
These results compare to prior landmark studies in this therapeutic area, such as the European Randomized Study of Screening for Prostate Cancer and the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, which reported mixed findings on mortality reduction and increased diagnosis of localised disease. This meta-analysis aligns with those observations but provides updated evidence with larger sample sizes and longer follow-up.
Key methodological limitations include study limitations, inconsistency, and imprecision that reduced confidence in effect estimates. Interpretation is highly sensitive to the choice of minimal clinically important difference (MCID). Insufficient evidence exists on potential harms such as biopsy- and treatment-related complications. Results on mortality for emerging alternatives like kallikrein panels and MRI are not yet known.
Clinically, screening likely reduces prostate cancer-specific mortality and may reduce overall mortality, but may have little to no effect on adverse events; interpretation depends on MCID thresholds. Practice decisions should consider individual patient risk, values, and preferences, given the moderate-certainty evidence for mortality reduction and increased diagnoses.
Unanswered questions include the long-term impact of screening on quality of life, the role of emerging biomarkers and imaging, and the balance of benefits and harms in diverse populations. Future research should address these gaps to inform personalized screening strategies.