Risk-based Prostate-specific Antigen Monitoring Reduces Follow-up Burden After Radical Prostatectomy.

Background and objective: The European Association of Urology (EAU)-recommended follow-up schedule after radical prostatectomy (RP)-biannual prostate-specific antigen (PSA) testing for 3 yr, followed by annual testing-does not take into account variations in biochemical recurrence (BCR) risk. Therefore, we propose an optimised, risk-adapted PSA monitoring schedule for the first 5 yr after RP, stratifying patients into BCR-based risk groups, to reduce unnecessary PSA testing without compromising BCR detection rates.

Methods: Men were diagnosed with localised prostate cancer in 2015-2016, who underwent primary RP, with undetectable PSA levels <6 wk after RP, as identified in the nationwide Netherlands Cancer Registry. The outcome measures included BCR-free survival (BCR defined as PSA ≥0.1 ng/ml). Cox proportional hazards models were used to identify three risk groups; Kaplan-Meier curves illustrated BCR-free survival rates. The average BCR risk per PSA follow-up consultation in the current EAU schedule was used as a threshold to determine consultations needed in the revised risk-based schedule.

Key findings and limitations: In total, 1043 patients were included in the study. Significant predictors for BCR included PSA at diagnosis, pT stage, pN stage, pathological International Society of Urological Pathology grade group, and positive surgical margins. Stratification (based on hazard ratio) resulted in 43% low-risk (15% BCR), 42% intermediate-risk (36% BCR), and 15% high-risk (72% BCR) patients. The overall 5-yr BCR-free survival rate was 62% (95% confidence interval 58-66). Low-risk patients required four, intermediate-risk patients required eight, and high-risk patients required ten consultations in the revised schedule over the first 5 yr, reducing 18% of consultations compared with the EAU schedule, with 3% delayed BCR detection. Study limitations include a potential bias due to informative censoring.

Conclusions and clinical implications: This optimised risk-adapted PSA monitoring schedule following RP reduced the number of unnecessary PSA tests, particularly in low-risk patients, without compromising BCR detection rates.