Top Line: Is acute toxicity associated with late toxicity following prostate radiation?
The Study: This sounds like a simple question, but it isn’t exactly clear whether late toxicity results directly from acute toxicity (termed consequential late toxicity) or develops independent of acute toxicity. This MARCAP meta-analysis of individual patient data from 6 randomized, phase 3 trials evaluated the link between acute and late GU and GI toxicity in 6593 patients treated with definitive radiation for localized prostate cancer. Among these, 64.4% were treated with conventional fractionation, 35.6% received moderate hypofractionation, and 40.5% received ADT. The rate of acute grade 2+ GU toxicity was 29.8%, and the rate of late grade 2+ GU toxicity was 15.4%. Acute GU toxicity was significantly associated with late toxicity (OR 2.2, P<0.0001), and the rate of late GU toxicity was significantly higher among those who experienced acute toxicity compared to those who did not (12.5% v 7.5%). Late GU toxicity was also higher among those treated with moderate hypofractionation. The rate of acute grade 2+ GI toxicity was 14.7%, and the rate of late grade 2+ GI toxicity was 14.3%. Acute GI toxicity was significantly associated with late GI toxicity (OR 2.53, P<0.0001), and the rate of late GI toxicity was higher among those who experienced acute toxicity (21.5% v 12.5%). Late GI toxicity was also associated with moderate hypofractionation.
TBL: This large meta-analysis shows that the development of late toxicity following prostate radiation is strongly associated with acute toxicity and that many late toxicity events are a direct consequence of acute toxicity. This suggests that treatment modifications that increase acute toxicity could likely translate to worse late toxicity. Likewise, interventions to minimize acute toxicity may also reduce the burden of late toxicity. | Nikitas, Lancet Oncol 2025
The Study: This sounds like a simple question, but it isn’t exactly clear whether late toxicity results directly from acute toxicity (termed consequential late toxicity) or develops independent of acute toxicity. This MARCAP meta-analysis of individual patient data from 6 randomized, phase 3 trials evaluated the link between acute and late GU and GI toxicity in 6593 patients treated with definitive radiation for localized prostate cancer. Among these, 64.4% were treated with conventional fractionation, 35.6% received moderate hypofractionation, and 40.5% received ADT. The rate of acute grade 2+ GU toxicity was 29.8%, and the rate of late grade 2+ GU toxicity was 15.4%. Acute GU toxicity was significantly associated with late toxicity (OR 2.2, P<0.0001), and the rate of late GU toxicity was significantly higher among those who experienced acute toxicity compared to those who did not (12.5% v 7.5%). Late GU toxicity was also higher among those treated with moderate hypofractionation. The rate of acute grade 2+ GI toxicity was 14.7%, and the rate of late grade 2+ GI toxicity was 14.3%. Acute GI toxicity was significantly associated with late GI toxicity (OR 2.53, P<0.0001), and the rate of late GI toxicity was higher among those who experienced acute toxicity (21.5% v 12.5%). Late GI toxicity was also associated with moderate hypofractionation.
TBL: This large meta-analysis shows that the development of late toxicity following prostate radiation is strongly associated with acute toxicity and that many late toxicity events are a direct consequence of acute toxicity. This suggests that treatment modifications that increase acute toxicity could likely translate to worse late toxicity. Likewise, interventions to minimize acute toxicity may also reduce the burden of late toxicity. | Nikitas, Lancet Oncol 2025