Long-Term Rates of Undetectable PSA with Initial Observation and Delayed Salvage Radiotherapy after Radical Prostatectomy

Background: Randomized trials have shown an improvement in progression-free survival rates with adjuvant radiation therapy (ART) after radical prostatectomy for patients with a high risk of cancer recurrence. Less is known about the relative advantages and disadvantages of initial observation with delayed salvage radiation therapy (SRT). Objective: To examine the results of SRT in a large single-surgeon radical prostatectomy series. Design, Setting, and Participants: From a radical prostatectomy database, we identified 859 men with positive surgical margins (SM+), extracapsular tumor extension (ECE), or seminal vesicle invasion (SVI) who chose to defer ART. Following a period of initial observation, 192 ultimately received SRT for prostate-specific antigen (PSA) progression. Measurements: Survival analysis was performed to examine the outcomes of initial observation followed by SRT. Results and Limitations: In patients with SM+/ECE and SVI, the 7-yr PSA progression-free survival rates with observation were 62% and 32%, respectively. Among those who had PSA progression, 56% and 26%, respectively, maintained an undetectable PSA for 5 yr after SRT. The long-term rates of undetectable PSA associated with an SRT strategy were 83% and 50% for men with SM+/ECE and SVI, respectively. In the subset of 716 men who did not receive any hormonal therapy, the corresponding long-term rates of undetectable PSA were 91% and 75%, respectively. Conclusions: Following radical prostatectomy, initial observation followed by delayed SRT at the time of PSA recurrence is an effective strategy for selected patients with SM+/ECE. Some patients with SVI may also benefit from this strategy. However, additional prospective studies are necessary to further examine the survival outcomes following SRT.