Hypofractionated Dose Escalation versus Conventionally Fractionated Radiotherapy for Patients with Intermediate- and High-risk Localized Prostate Cancer: Long-term Results of the HYPRO trial
Mené sur 804 patients atteints d'un cancer de la prostate de stade localisé à risque intermédiaire ou élevé de récidive, cet essai randomisé multicentrique de phase III évalue la supériorité, du point de vue de la survie sans récidive à 10 ans, d'une radiothérapie hypofractionnée avec escalade de doses par rapport à une radiothérapie avec fractionnement conventionnel
Background: The HYpofractionated irradiation for PROstate cancer (HYPRO) trial was a multicenter, randomized, phase 3, superiority trial comparing dose escalated hypofractionation (HF) with conventional fractionation (CF) for the treatment of localized intermediate- and high-risk prostate cancer. This trial aimed to demonstrate equivalent toxicity of HF. In prior publications, non-inferiority of acute and late toxicity could not be established. Here we report the long-term survival outcomes.
Methods: We randomly assigned patients (1:1) with intermediate- to high-risk T1b-T4NX-N0MX-M0 localized prostate cancer to receive either HF (64.4 Gy in 19 fractions of 3.4 Gy, 3 fractions per week) or CF (78.0 Gy in 39 fractions of 2 Gy, 5 fractions per week) radiation therapy. The HF schedule was a dose escalation compared with CF, based on a α/β ratio of prostate cancer of approximately 1.5 Gy, the equivalent total dose in fractions of 2 Gy is 90.4 Gy for HF versus 78.0 Gy for CF. The primary endpoint of this paper was relapse-free survival at 10 years and secondary outcome was overall survival.
Results: Of the 820 patients, 804 were included in the current evaluation, 407 patients received HF and 397 CF radiation therapy. The 10-year relapse-free survival was 64.5% (95% CI, 58.6 - 69.7) in the HF arm compared with 60.1% (95% CI, 53.9 - 65.8) in the CF arm (HR:0.89, 95% CI, 0.69 - 1.14; P = 0.35). The 10-year overall survival in the HF arm was 69.2% (95% CI, 64.1 - 73.7) versus 61.2% (95% CI, 55.7 - 66.2) in the CF arm (HR: 0.82, 95% CI, 0.65 - 1.05; P=0.11).
Conclusion: In the updated findings, we could not demonstrate a statistically significant improvement in 10-year relapse-free survival following dose escalated HF compared to CF. Although patients in the HF arm showed favorable 10-year overall survival, this difference did not remain statistically significant in the multivariable analysis.
International Journal of Radiation Oncology, Biology, Physics , résumé, 2025