Salvage radiotherapy in prostate cancer patients with biochemical relapse after radical prostatectomy

Background

In patients with prostate cancer (PCa) and biochemical progression (BP) after radical prostatectomy (RP), salvage radiotherapy (sRT) improves prostate cancer-specific survival (PCSS), but this evidence is based only on retrospective data.

Patients and methods

In addition to our previous study of 151 patients with PCa and BP after RP, we performed univariate analyses of prostate-specific antigen (PSA) kinetics during sRT. In 11 patients with BP or initiation of hormonal treatment (HT) within 180 days after sRT, risk factors were assessed using Mann–Whitney U tests. PSA doubling times (PSADT) before and after sRT in 82 patients with BP after sRT were compared by a Wilcoxon test.

Results

After a median follow-up of 82 months, analysis of PSA kinetics during sRT did not show a statistically significant impact on a subsequent BP, PCSS, or overall survival at an administered dose of 30 or 45?Gy. The subgroup analysis of patients with early BP or early HT revealed higher Gleason scores (p = 0.008) and preoperative PSA values (p = 0.005), shorter PSADT prior to sRT (p < 0.0005), and longer time intervals from RP until the start of sRT (p = 0.005) compared to all other patients. In patients with subsequent BP, PSADTs were significantly prolonged after sRT (median PSADT 4.5 months before and 9.9 months after sRT, p < 0.0005).

Conclusion

PSA monitoring during sRT did not predict the therapeutic success. Subgroup analysis suggests a lower probability of benefit for patients with the abovenamed risk factors . However, the prolonged PSADT after sRT reflects a benefit of sRT for the vast majority of patients.