Short-Term ADT Plus High-Dose RT Boosts DFS for Intermediate- and High-Risk PCa

There is a lack of data on the use of short-term androgen deprivation therapy (stADT) in combination with high-dose radiotherapy (RT) versus RT alone for patients with localized prostate cancer (PCa). The recent GETUG 14 randomized phase III trial has analyzed stADT plus RT to gain more insight on these treatments.

Previous research has demonstrated the benefit of stADT for 4 months before and during RT for localized, intermediate-risk PCa. GETUG 14 recruited 376 patients with both intermediate- and high-risk PCa, randomizing them to receive either RT (n=191) or stADT plus RT (n=179).

RT was administered in 80Gy doses in both treatment arms, while stADT was comprised of monthly triptorelin and daily flutamide for a total of 4 months, starting 2 months before irradiation.

The primary endpoint was disease-free survival (DFS), and secondary endpoints included overall survival (OS), biochemical failure (BF), metastasis failure (MF), toxicity, and quality of life (QoL).

At a median follow-up of 84 months, the 5-year DFS was 76% in the RT arm versus 84% in the stADT plus RT arm (HR=0.64; [95% CI 0.43 – 0.89]; P=.02). stADT was found to decrease BF (HR=0.45; P=.001) and MF (HR=0.5; P=.09), but not OS (HR=1.22; P=.54).

There was no difference regarding gastrointestinal (26% of grade ≥2 in both arms, P=.97) and genitourinary acute toxicity (39% for RT and 42% for stADT plus RT, P=.55), and no difference was found in late toxicity and QoL.

GETUG 14 found that stADT can improve DFS in patients with intermediate- and high-risk prostate cancer when combined with high-dose RT without negative effects on safety profiles.