Guideline of guidelines: a critical appraisal of the evidence for PSA retesting intervals

Objectives: To summarise the recommendations for prostate-specific antigen (PSA) retesting intervals and to evaluate the evidence cited by each guideline by conducting a systematic review of clinical practice guidelines. Methods: We searched PubMed and the Turning Research into Practice (TRIP) database for guidelines written in English and developed or updated in 2013–2024. Guideline quality assessment was performed using the AGREE II tool. We narratively synthesised results. Results: Eleven guidelines were included. Ten (91%) recommended PSA retesting intervals of approximately 2 to 4 years. A total of 37 studies were referenced as evidence for the recommended intervals across the 11 guidelines. Five of these studies (14%) had the objective of determining PSA retesting intervals. Fourteen studies (38%) analysed single PSA test results. Five guideline recommendations partially aligned with the evidence referenced and five did not align. Conclusions: Generally, for asymptomatic patients aged ≥50 years with PSA levels between 1 and 3 ng/mL, most guidance recommended a retesting interval of 2–4 years, with the possibility to extend the interval to 4–10 years for patients with a PSA value <1 ng/mL. Until research generates direct evidence for PSA retesting intervals for both asymptomatic and symptomatic patients, clinicians and patients engaging in shared decision-making should be aware that current guidelines lack direct evidence for recommended PSA retesting intervals.