A shorter course of radiotherapy, administered through fewer, higher intensity doses, is as well tolerated over five years as longer treatment courses for treating prostate cancer, long-term results of a clinical trial show.
The findings from the CHHiP trial, designed to assess the safety and side effects of using higher doses of radiotherapy in fewer sessions, support a shorter treatment plan that allows men to finish treatment sooner.
The results confirm a shorter dosing schedule is tolerable for patients – meaning they can undergo treatment without experiencing excessive side effects. This suggests that all men with prostate cancer that has not spread should be offered this type of radiotherapy treatment, as it means fewer trips to hospital without negatively affecting men’s quality of life in the long term.
The trial, led by a team at The Institute of Cancer Research, London, and The Royal Marsden NHS Foundation Trust, recruited 3,216 men and randomly divided them into three treatment groups to examine the immediate and long-term effects of different dosing schedules on bowel, urinary, and sexual function.
Patients' quality of life
Findings from the CHHiP trial, funded by Cancer Research UK, reported in 2016 showed the effectiveness of shorter course treatments, which changed practice in the UK and internationally. This meant men could attend 20 radiotherapy sessions over four weeks instead of 37 over seven and a half weeks.
Patients were followed up for a period of five years, including annual checks. The findings, published in European Urology Oncology, provide reports from patients about their own quality of life after receiving the treatment, confirming the long-term tolerability of shorter treatment schedules.
The quality of life questionnaire, completed by 2,100 participants throughout the study, confirmed that shortening the dosing schedule did not increase the risk of bowel, urinary and sexual side effects.
One group of men in the trial received the standard radiotherapy treatment dose of 74 Gy over 37 days (2 Gy per day). The other two groups received higher doses of radiotherapy in fewer sessions (‘hypofractionated’ treatment). 60 Gy over 20 days (3 Gy per day) or 57 Gy in 19 days (3 Gy per day), cutting their treatment schedule from seven and a half weeks to just four.
No increase in troublesome side effects
According to the questionnaires completed, at five years the prevalence of troublesome bowel-associated side effects was similar for all treatment groups – 5.4 per cent for those who received the standard 74Gy compared to 7.6 per cent for the 60Gy group and 5.3 per cent for the 57Gy group. The five-year prevalence of moderate or high sexual side effects was 41.7 per cent, 36.6 per cent and 40.7 per cent, respectively.
Meanwhile, the five-year prevalence for troublesome urinary side effects was 6.7 per cent for those who received the standard 74Gy, 9.3 per cent for 60Gy and 7.8 per cent for the 57Gy group.
The CHHiP trial involved testing different doses of intensity modulated radiotherapy (IMRT), a technique developed at The Institute of Cancer Research (ICR) and The Royal Marsden. IMRT adjusts the size and shape of the radiation beam to match the tumour, providing precise treatment directly to the cancer. The trial encouraged the adoption of IMRT in the UK and IMRT is now used routinely.
The trial, involving 71 study locations, was coordinated through the ICR Clinical Trials and Statistics Unit (ICR-CTSU), which leads the design, conduct and analysis of phase II and III national and international cancer clinical trials.
Prostate cancer is the most prevalent cancer in men in the UK with radiotherapy centres spending the majority of their time treating prostate cancer patients. Introducing shorter treatment schedules means men are spared additional hospital visits, saving costs and reducing pressure on the NHS.
The importance of listening to patients
Professor David Dearnaley, Emeritus Professor of Uro-Oncology at The Institute of Cancer Research, London, and Consultant Clinical Oncologist at The Royal Marsden NHS Foundation Trust, who designed and led the study clinically, said:
“The CHHiP trial results changed clinical practice and shortened treatments for many men. We are now delighted to see that our results confirm that patients report a low level of side-effects up to 5 years after high quality radiotherapy. The study results offer reassurance over the long-term benefits of the approach.
“We’re now trying to reduce the number of fractions further and that will have all the knock-on effects of reduced patient visits, saved costs and greater convenience for patients. But the results from this trial are really important because we now have consistent, highly satisfactory results five years on.”
Professor Emma Hall, Deputy Director of the Clinical Trials and Statistics Unit at The Institute of Cancer Research, London, who co-led the CHHiP trial, said:
“It’s important to listen to patients. This study confirms from the patient perspective that a shorter, higher dose radiotherapy treatment schedule does not increase the risk of side effects compared to a longer, lower dose schedule.
“Our latest results reaffirm the claim that all men should be offered this type of prostate radiotherapy treatment as opposed to the longer treatment schedules.”