Objectives: Patients may undergo prostate-specific antigen (PSA) testing due to symptoms or by request. Unless the result of the test is clearly abnormal it is unclear whether PSA should be retested and if it should, at what interval. The aim of this systematic review of clinical practice guidelines was to summarise the recommendations for PSA retesting intervals and evaluate the evidence cited by each guideline.

Methods: We searched PubMed and TRIP for guidelines written in English and developed or updated in 2013-2024. Guideline quality assessment was done using the AGREE II tool. We narratively synthesised results.

Results: Eleven guidelines were included. Ten (91%) recommended PSA retesting intervals around two-to-four years. 37 studies were referenced as evidence for the recommended intervals across the eleven guidelines. Five (14%) of these had the objective of determining PSA retesting intervals. 14(38%) studies analysed single PSA test results. Five (45%) guideline recommendations partially aligned with the evidence referenced and five (45%) did not align.

Conclusions: Generally, for asymptomatic patients aged 50+ with PSA levels between 1 and 3ng/ml, most guidance recommended a retesting interval of two-to four-years with the possibility to extend the interval to four-to-ten years for patients with a PSA value