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.