Men with a high risk of prostate cancer recurrence could live longer if hormone treatment is given alongside radiotherapy after surgery, a new study has suggested.
The research, published in the New England Journal of Medicine, found that the treatment could also reduce the risk of the disease spreading.
Professor Nick James, a Cancer Research UK-funded expert in prostate cancer at the University of Birmingham, said the results could be “practice-changing”.
“It shows that the benefits in terms of relapse and survival are both clinically and statistically highly significant,” he added.
The US-based clinical trial looked at 760 men whose prostate had been removed with surgery after diagnosis, but who had the risk of their cancer spreading, as defined by a blood test.
Following surgery patients received radiotherapy to try to kill any cancer cells that may have been left behind. Then over the next 2 years, half received an anti-androgen drug called bicalutamide while the other half received a placebo.
The study found that the men who received the drug had a slightly higher chance of being alive 12 years after the start of the trial than those who took the placebo.
The chance of dying from prostate cancer was also lower in the group who received the drug. 1 in 20 patients in the hormone treatment group later died from prostate cancer, compared to just under 3 in 20 deaths for the placebo group.
“This important trial is the first to study patient survival following radiotherapy given to eradicate any cancer cells that might be left after surgery,” said James.
The risk of the cancer spreading (metastasis) was also reduced for the group receiving the drug. 3 in 20 of the patients receiving bicalutamide were found to have tumours that had spread, while 5 in 20 patients on the placebo saw their disease spread.
Professor David Dearnaley, an expert in radiotherapy at The Institute of Cancer Research, London, part-funded by Cancer Research UK, said the findings for the hormone treatment may have positive consequences.
He said: “This drug isn’t yet licensed to be used routinely in this way, but in some men it might significantly improve quality of life compared with current treatments.”
But he added a note of caution regarding side effects: “The downside of the treatment is a high level of breast swelling (gynaecomastia), although this can be reduced by using anti-oestrogen treatment or low-dose breast radiotherapy.”
Shipley, W. U. et al. Radiation with or without Antiandrogen Therapy in Recurrent Prostate Cancer. N Engl J Med 2017;376:417-428 DOI: 10.1056/NEJMoa1607529