Early initiation of salvage hormone therapy influences survival in patients who failed initial radiation for locally advanced prostate cancer: A secondary analysis of RTOG protocol 86-10

Abstract

Purpose: We examined overall and disease-specific survival outcomes both from the time of initial treatment and from the start of salvage hormone therapy (HT), by the extent of disease progression at the time salvage HT was started in patients treated on RTOG Protocol 86-10.

Methods: [corrected] With a median follow-up of 9.0 years, 247 patients (54%) had received subsequent salvage HT. The overall survival (OVS) and disease-specific survival (DSS) were compared by the extent of disease progression at the time salvage HT was started.

Results: For those patients with distant metastases (DM) present at the start of salvage HT, the OVS and DSS were significantly reduced when compared to [corrected] those with DM absent at the time salvage HT was started (OVS at 8 years, 31% vs. 58%; DSS at 8 years, 38% vs. 65%). A statistically significant increase in DSS was observed among the 143 patients with DM absent when patients with prostate-specific antigen (PSA) less than 20 were compared with those with PSA greater than 20 at the time salvage HT was started.

Conclusion: [corrected] The DSS and the OVS of the relapsed patient are decreased in those with more extensive disease at the time of salvage HT. However, because this protocol could not evaluate the effect of posttreatment PSA velocity on outcomes, which is likely a better predictor of long-term success with salvage HT, these results cannot be taken to demonstrate that early salvage HT in patients with long posttreatment PSA doubling times is necessary for longer survival.