The randomised controlled trial, known in the UK as PR07, recruited 1,205 men between 1995 and 2005. The men, who were predominantly from the UK and Canada, had been diagnosed with locally advanced prostate cancer which had grown outside the surface of the prostate but had not spread further. Half of the men were treated with hormone therapy, a standard form of drug treatment, and the other half were treated with a combination of the same hormone therapy plus an additional course of radiotherapy.
By providing radiotherapy in addition to hormone therapy, the researchers found that 74 per cent of men were still alive after seven years, compared with 66 per cent who did not receive radiotherapy. The researchers also found that those who received radiotherapy were about half as likely to die specifically from their prostate cancer.
Prostate cancer accounts for 10,000 male deaths in the UK each year and is the second most common cause of cancer death in men, after lung cancer. The trial was conducted because it was unknown whether radiotherapy would help to these men to live longer as well as reducing their chances of dying from their prostate cancer.
Matthew Sydes, senior scientist at the MRC Clinical Trials Unit, says: “The results of this trial are extremely encouraging. The additional side-effects of radiotherapy are minimal and we are delighted that, through the combined efforts of patients, clinicians and researchers across the world, we can be confident when doctors recommend radiotherapy for their patients. Further research is currently underway to improve outcomes for prostate cancer patients.”
Professor Malcolm Mason from Cardiff University and co-author on the paper says: “We’re very grateful to all the men who took part in this trial and we’re delighted that the trial has shown that radiotherapy is extremely worthwhile for patients with prostate cancer that is locally advanced. The next stage will be to ensure that the results of this trial are implemented into treatment recommendations as quickly as possible.”
Principal investigator Padraig Warde, deputy head at Princess Margaret Hospital radiation medicine program at Toronto’s University Health Network, says: “The study shows that combining radiation and hormone therapy improves overall survival by 23 percent in relative terms and disease-specific survival by 43 percent in relative terms, compared with treating with hormone therapy alone. Based on these results, we believe adding radiation to the treatment plan should become part of the standard therapy.”
Professor Max Parmar, director of the MRC Clinical Trials Unit, says: “Well-conducted large scale clinical trials, such as PR07, are essential to making sure that treatment decisions are based on the best possible evidence. By answering the important question of whether prostate cancer patients would benefit from radiotherapy, we have hopefully altered the way this disease will be treated from now on.”
Notes to editors: