Adding hormone therapy to definitive radiotherapy in localized prostate cancer improves overall survival, but whether it similarly improves overall survival in the context of postoperative radiotherapy (PORT) after radical prostatectomy is unclear. Authors report individual patient data (IPD) meta-analysis of randomized trials aimed at quantifying the benefit of adding hormonal therapy to PORT.

Authors conducted a systematic literature search that identified randomized, phase 3 trials of PORT with or without hormone therapy in MEDLINE, Embase, trial registries, the Web of Science, Scopus, and relevant conference proceedings. IPD were available via the MARCAP consortium. The primary outcome was overall survival. Meta-analyses evaluated the benefit of adding hormone therapy, short-term hormone therapy (4–6 months), or long-term hormone therapy (24 months) to PORT. Tests for interaction based on pre-PORT prostate-specific antigen (PSA) and duration of hormone therapy were evaluated and non-linear associations between pre-PORT PSA and overall survival were modeled. Patient data were available for six randomized trials including 6,057 patients with a median follow-up of 9.0 years.

Findings: Adding hormone therapy to radiotherapy did not significantly improve overall survival. There was no significant interaction between hormone therapy duration and this effect, although there was a significant interaction with pre-PORT PSA greater than 0.5 ng/mL versus 0.5 ng/mL or less. For all pre-PORT PSA values, the upper bounds of the 95% CI of the HR for overall survival crossed 1.0 for patients randomly assigned to PORT with or without short-term hormone therapy (n = 3,938). For patients randomly assigned to PORT with or without long-term hormone therapy (n=1,088), the upper bounds of the 95% CI for overall survival HR fell below 1.0 at PSA greater than 1.6 ng/mL.