A shorter course of radiotherapy for localized prostate cancer is as safe and effective as the traditional eight-week schedule, even a decade after treatment, according to a 10-year analysis of the phase III HYPO-RT-PC trial published in The Lancet Oncology.
The study, conducted across ten centers in Sweden and two in Denmark between July 2005 and November 2015, involved 1,180 men aged 75 or younger with intermediate- or high-risk prostate cancer. Participants were randomly assigned to receive either ultra-hypofractionated radiotherapy – 42.7 Gy in seven fractions over 2.5 weeks, three days per week – or conventionally fractionated radiotherapy, delivering 78.0 Gy in 39 fractions over eight weeks, five days per week. Patients enrolled in the trial had not previously undergone or were not currently receiving androgen deprivation therapy.
Researchers followed the patients for a median of 10.7 years, tracking failure-free survival, defined as the time from randomization to biochemical failure, clinical progression, initiation of androgen deprivation therapy, or death from prostate cancer. The analysis revealed a 10-year failure-free survival rate of 72% (95% confidence interval: 68%-76%) in the ultra-hypofractionated group, compared to 65% (95% confidence interval: 61%-69%) in the conventionally fractionated group. The adjusted hazard ratio was 0.84 (95% confidence interval: 0.69–1.03), confirming the non-inferiority of the shorter treatment course.
The study too assessed toxicity levels. At 10 years, the cumulative incidence of late grade 2 or higher genitourinary toxicity was 30% (95% confidence interval: 26%-34%) in the conventional radiotherapy group and 28% (95% confidence interval: 24%-32%) in the ultra-hypofractionated group (hazard ratio = 1.01, 95% confidence interval: 0.81–1.25). Late grade 2 or higher gastrointestinal toxic effects were similarly reported in 14% (95% confidence interval: 11%-18%) of patients receiving conventional radiotherapy and 14% (95% confidence interval: 11%-17%) of those receiving the ultra-hypofractionated regimen (hazard ratio = 0.94, 95% confidence interval: 0.70–1.28).
“This 10-year follow-up confirms the non-inferiority of the ultra-hypofractionated radiotherapy regimen compared with the conventionally fractionated, with similar toxicity profiles,” stated the investigators in their published conclusions. “The findings support the seven-fraction schedule as a safe, effective, and practical standard-of-care option for patients with intermediate-risk prostate cancer.”
The HYPO-RT-PC trial was funded by The Nordic Cancer Union, Swedish Cancer Society, Swedish Research Council, and others. The study, initially presented at ESTRO 2025, builds on previous findings demonstrating the non-inferiority of ultra-hypofractionated radiotherapy in failure-free survival, as reported in the primary analysis of the trial.
