PSA Testing Protocol After Radical Prostatectomy
Measure serum PSA every 6-12 months for the first 5 years after radical prostatectomy, then annually thereafter, with the first PSA obtained at 6 weeks to 3 months post-surgery. 1, 2
Initial Post-Operative PSA Testing
- Obtain the first PSA at 6 weeks to 3 months after surgery to allow adequate washout time and avoid false elevations from surgical inflammation 1, 2, 3
- PSA should drop to undetectable levels (<0.1 ng/mL or <0.2 ng/mL depending on assay sensitivity) within the first 2 months after radical prostatectomy 1, 2, 4, 3
- If PSA is detectable on initial testing, repeat in 1-3 months to confirm elevation and calculate PSA doubling time (PSADT) 2, 3
Standard Surveillance Schedule
First 5 Years Post-Surgery
- PSA testing every 6-12 months is the standard recommendation across major guidelines 1
- For high-risk patients, consider PSA testing every 3 months during the first 2 years due to increased recurrence risk 1
- The NCCN recommends every 6-12 months for 5 years based on uniform consensus 1
After 5 Years
- Annual PSA testing is sufficient for long-term surveillance 1
- Continue indefinitely as 96% of recurrences occur within 10 years, though late recurrences can occur 1
Definition of Biochemical Recurrence
- PSA ≥0.2 ng/mL confirmed on a subsequent test is the most widely accepted definition of biochemical recurrence, used in 35 of 145 studies reviewed 1, 2, 4
- This threshold represents the optimal balance between sensitivity for detecting true recurrence and specificity to avoid false positives from benign remnant tissue 1, 2, 4
- Any detectable PSA should be confirmed with repeat testing to eliminate laboratory error before declaring biochemical failure 1, 2
PSA Kinetics and Clinical Significance
Timing of Recurrence
- Early recurrence (<24 months) with rapid PSA rise suggests metastatic disease 2
- Late recurrence (>24 months) with slow PSA rise suggests local recurrence amenable to salvage radiotherapy 2
PSA Doubling Time (PSADT)
- PSADT <6 months indicates high risk of metastatic progression and poor prognosis 2, 3
- PSADT >10 months suggests local recurrence and better prognosis 2, 3
- PSADT <10-12 months correlates with high risk of 10-year mortality 3
Management of Detectable PSA
- Refer immediately to the primary treating specialist for any confirmed detectable or rising PSA 1, 4
- After radical prostatectomy, any confirmed detectable PSA is an indication for specialist referral as it suggests residual or recurrent disease 1
- Salvage radiotherapy should be offered when PSA is rising and there is no evidence of distant metastases, with better outcomes when PSA <2.0 ng/mL at treatment initiation 1, 2, 4
Ancillary Testing
Digital Rectal Examination (DRE)
- Perform annual DRE to monitor for local recurrence, as rare cases can occur without PSA elevation 1
- DRE may be omitted if PSA remains undetectable, though this is at clinician discretion 1
Imaging
- No routine imaging is necessary before biochemical recurrence unless complications are suspected 2, 4
- With PSA <5 ng/mL and PSADT <10 months, conventional imaging (bone scan, CT) is unlikely to detect recurrence 2
- MRI can identify local recurrence with PSA <1 ng/mL if salvage therapy is being considered 2
Common Pitfalls to Avoid
- Do not use different PSA assays for longitudinal monitoring, as laboratory variability can range 20-25% 4
- Do not delay repeat PSA testing when initial post-operative PSA is detectable—confirm within 1-3 months 2, 3
- Do not wait for symptoms to develop before acting on rising PSA, as early salvage therapy improves outcomes 1, 2
- Be aware that 8.8% of patients may have stable detectable PSA for 10+ years without clinical failure, though this requires specialist evaluation 2
Risk-Stratified Approach
Low-Risk Patients
- Standard surveillance every 6-12 months for 5 years, then annually 1
Intermediate-Risk Patients
- Consider more frequent monitoring (every 6 months) during first 2 years 1