Local prostate cancer radiotherapy after prostate-specific antigen progression during primary hormonal therapy.

Background: The outcome of patients after radiotherapy (RT) for localized prostate cancer in case of prostate-specific antigen (PSA) progression during primary hormonal therapy (HT) is not well known.

Methods: A group of 27 patients presenting with PSA progression during primary HT for local prostate cancer RT was identified among patients who were treated in the years 2000-2004 either using external-beam RT (EBRT; 70.2 Gy; n=261) or Ir-192 brachytherapy as a boost to EBRT (HDR-BT; 18 Gy + 50.4 Gy; n=71). The median follow-up period after RT was 68 months.

Results: Median biochemical recurrence free (BRFS), disease specific (DSS) and overall survival (OS) for patients with PSA progression during primary HT was found to be only 21, 54 and 53 months, respectively, with a 6-year BRFS, DSS and OS of 19%, 41% and 26%. There were no significant differences between different RT concepts (6-year OS of 27% after EBRT and 20% after EBRT with HDR-BT).Considering all 332 patients in multivariate Cox regression analysis, PSA progression during initial HT, Gleason score>6 and patient age were found to be predictive for lower OS (p<0.001). The highest hazard ratio resulted for PSA progression during initial HT (7.2 in comparison to patients without PSA progression during primary HT). PSA progression and a nadir >0.5 ng/ml during initial HT were both significant risk factors for biochemical recurrence.

Conclusions: An unfavourable prognosis after PSA progression during initial HT needs to be considered in the decision process before local prostate radiotherapy. Results from other centres are needed to validate our findings.