PSA as a Marker for Tumor Recurrence After Total Prostatectomy

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, 3
Any detectable PSA following radical prostatectomy should be repeated 1-3 months later to confirm elevation and estimate PSA doubling time (PSADT) 1

A cutpoint between 0.2 and 0.4 ng/mL appears most accurate for defining biochemical recurrence that will ultimately translate into clinical failure 4, 5
Lower PSA threshold values increase sensitivity for detecting recurrence while higher values improve specificity 5
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 6

PSA patterns help differentiate local from distant disease recurrence 1, 7
Patients with late BCR (>24 months after treatment), low PSA velocity, or prolonged PSADT (>6 months) likely have recurrent local disease 1, 8
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, 7, 8

PSA alone cannot differentiate between local and distant disease recurrence, though PSA kinetics help predict the pattern 1, 8
A small percentage of patients (8.8%) may have detectable but stable PSAs for 10+ years without evidence of clinical failure 6

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 6, 9
Re-staging evaluation may be considered in patients with PSA recurrence to determine the site of recurrence (local vs. metastatic) 6

With PSA <5 ng/mL and PSADT <10 months, conventional imaging like bone scans and CT are unlikely to detect recurrence 1, 2
MRI can identify isolated local recurrences with PSA levels <1 ng/mL 2