PSA as a Marker for Tumor Recurrence After Total Prostatectomy
Yes, PSA is a reliable marker for tumor recurrence after total prostatectomy, as it becomes undetectable (<0.1 ng/mL) within one month after successful surgery in the absence of residual cancer. 1
Definition of Biochemical Recurrence
- Biochemical recurrence (BCR), also called PSA recurrence or PSA failure, is the most clinically used endpoint for identifying treatment failure after radical prostatectomy 1
- After total prostatectomy, PSA should become undetectable (<0.1 ng/mL) by the first month following surgery 1
- Any detectable PSA following radical prostatectomy should be repeated 1-3 months later to confirm elevation and estimate PSA doubling time (PSADT) 1
Diagnostic Criteria for Recurrence
- A cutpoint between 0.2 and 0.4 ng/mL appears most accurate for defining biochemical recurrence that will ultimately translate into clinical failure 1
- Lower PSA threshold values increase sensitivity for detecting recurrence while higher values improve specificity 1
- In the era of ultrasensitive PSA assays, a detectable PSA that is confirmed and rising may be an appropriate trigger for salvage therapy, particularly in high-risk patients 1
Patterns of PSA Rise and Clinical Significance
- PSA patterns help differentiate local from distant disease recurrence 1
- Patients with late BCR (>24 months after treatment), low PSA velocity, or prolonged PSADT (>6 months) likely have recurrent local disease 1
- Patients with rapid PSA recurrence (<24 months after treatment), high PSA velocity, or short PSADT (<6 months) are more likely to have metastatic recurrence 1
Limitations and Considerations
- PSA alone cannot differentiate between local and distant disease recurrence, though PSA kinetics help predict the pattern 1
- A small percentage of patients (8.8%) may have detectable but stable PSAs for 10+ years without evidence of clinical failure 1
- In rare cases, PSA-negative tumor recurrences can occur, though this is uncommon 2
- Some benign tissue at surgical margins can produce low PSA levels, but persistent/recurrent detectable PSA after radical prostatectomy generally indicates biochemical failure 3
Recommendations for Monitoring
- First serum PSA assay should be performed 3-12 months after radical prostatectomy 1
- No imaging is necessary after definitive treatment before biochemical recurrence unless complications are suspected 1
- When PSA recurrence is detected, salvage radiotherapy should be administered at the earliest sign of PSA recurrence if there is no evidence of distant metastases 1
- Re-staging evaluation may be considered in patients with PSA recurrence to determine the site of recurrence (local vs. metastatic) 1
Imaging for Recurrence
- With PSA <5 ng/mL and PSADT <10 months, conventional imaging like bone scans and CT are unlikely to detect recurrence 1
- MRI can identify isolated local recurrences with PSA levels <1 ng/mL 1
- Prostate-specific membrane antigen (PSMA) PET/CT outperforms MRI for identifying recurrence in lymph nodes and bones 4
PSA monitoring remains the cornerstone of post-prostatectomy surveillance, with its pattern of rise providing valuable information about the likely site of recurrence and guiding subsequent management decisions.