Salvage radiotherapy for rising or persistent PSA after radical prostatectomy.

OBJECTIVES: To assess the effectiveness of salvage radiotherapy (RT) for a persistent or rising prostate-specific antigen (PSA) level after radical prostatectomy, and to identify the pretreatment factors that may predict for patients likely to benefit from this treatment.
METHODS: Seventy-three consecutive patients were treated during a 10-year period (1989 to 1999) with RT after radical prostatectomy. Twelve patients were excluded from analysis because of either an undetectable PSA level before RT or lack of follow-up data. No patients had clinical or radiographic evidence of distant disease. An undetectable PSA level (less than 0.1 ng/mL) was required to be considered disease free.
RESULTS: The median PSA level before RT was 0.8 ng/mL (range 0.1 to 63). The median radiation dose prescribed was 66.6 Gy. The actuarial PSA-free survival rate at 4 years was 39%. Failure was uncommon in patients followed up beyond 4 years. Univariate analysis revealed that a pre-RT PSA level of less than 1.0 ng/mL (P = 0.001), Gleason score less than 8 (P = 0.003), and achievement of an undetectable PSA level after prostatectomy (P = 0.018) were significant predictors of improved disease-free survival. On multivariate analysis, both a pre-RT PSA level of less than 1.0 ng/mL and a Gleason score less than 8 maintained statistical significance.
CONCLUSIONS: Salvage RT provides a reasonable chance of intermediate-term disease-free survival in patients with PSA persistence or relapse after radical prostatectomy. Patients with a higher PSA level (greater than 1 ng/mL) and Gleason score of 8 or more are less likely to benefit from this treatment, and improved therapies are needed for this subset of patients. Patients should be referred promptly for salvage RT after detection of relapse.