Adjuvant versus neoadjuvant androgen deprivation with radiotherapy for prostate cancer: does sequencing matter?

Androgen deprivation therapy (ADT) is typically provided neoadjuvantly and concurrently with radiotherapy (RT) in the management of intermediate and high-risk prostate cancer. Our objective was to compare outcomes between patients who received adjuvant ADT (ADJ), ie, immediately after the completion of RT, to those who received a neoadjuvant and concurrent regimen (NEO).

From 1995 to 2002, 515 patients with prostate cancer were definitively treated with RT and ADT. NEO was provided 2 to 3 months before the start of RT (n = 311). ADJ was initiated immediately after the completion of RT (n = 204). Kaplan-Meier analysis was used to calculate biochemical relapse-free survival (bRFS), distant metastasis-free survival (DMFS), and overall survival (OS). Cox proportional hazards regression was used to examine the impact of ADT timing on outcomes.

Ten-year bRFS, DMFS, and OS rates were 61%, 80%, and 66%, respectively. Ten-year bRFS rates for ADJ versus NEO were 63% versus 60% (P = .98). Ten-year DMFS rates for ADJ versus NEO were both 80% (P = .60). Ten-year OS rates for ADJ versus NEO were 65% versus 67% (P = .98).

There was no significant difference in bRFS, DMFS, or OS between neoadjuvant versus adjuvant ADT in the setting of dose-escalated RT for localized prostate cancer. This suggests that the synergy between RT and androgen deprivation is independent of the sequencing of both modalities and that the initiation of RT does not need to be delayed for a course of neoadjuvant ADT.