San Francisco, California (UroToday.com) The optimal dose and scheduling of prostate radiation for significant prostate cancer remains an important clinical question that has been addressed in large randomized clinical trials with both efficacy and safety/quality of life endpoints. The Phase III CHHiP trial was a non-inferiority randomized study of conventional versus hypofractionated high dose intensity modulated radiotherapy of three different schedules, previously reported in Lancet Oncology in 2016. In the Prostate Cancer Rapid Abstract Session, Prof David Dearnley presented long-term study update of both efficacy and safety results from this pivotal study.
The CHHiP study enrolled patients with clinical stage T1b-T3a, lymph node-negative, non-metastatic prostate cancer with a lower risk of seminal vesicle involvement and PSA less than 30 ng/ml. Patients were randomized in a 1:1:1 fashion to three schedules: 74Gy in 37 fractions over 7.4 weeks (conventional schedule) vs 60Gy in 20 fractions over 4 weeks vs 57Gy in 19 fractions over 3.8 weeks. In total, over 3000 patients were enrolled. Importantly, the study was designed as a non-inferiority study with a critical hazard ratio of 1.21 for each hypofractionated schedule compared to the conventional schedule of 74Gy in 37 fractions.
Baseline characteristics of the large study population were a median age of 69 years. 15%, 73% and 12% of patients were categorized in low, intermediate and high risk groups, respectively. However, central pathology review of a subset of more than half of patients do upstage the risk of patients to high-risk at 19%. The majority of tumors with clinical T stage T1-T2 with a median pre-hormonal therapy PSA level of 10ng/ml.
Presented by: David Dearnley, MA, MB, BCh, MD, FRCP, FRCR, Professor, Institute of Cancer Research, UK
Written by: Anis Hamid, MBBS, Medical Oncology Research Fellow at Dana-Farber Cancer Institute and Medical Oncologist, PhD candidate, University of Melbourne, Australia (Twitter: @anis_a_hamid) at the 2020 Genitourinary Cancers Symposium, ASCO GU #GU20, February 13-15, 2020, San Francisco, California