Combined therapy helps prostate cancer patients live longer

01 November 2011

DrPadraig WardeNovember 2011 – Patients with high-risk or locally advanced prostate cancer live longer if they are treated with a combination of radiation and hormone therapy, according to findings from a Canadian-led clinical trial.

The results provide an important new treatment option and are expected to change clinical practice worldwide. Until now, most clinicians thought that patients with locally advanced or high-risk prostate cancer should be treated with hormone therapy only because radiation therapy was not an established treatment for these patients.

“Based on these results, we believe adding radiation to the treatment plan should become part of the standard therapy,” says DrPadraig Warde, the study’s principal investigator. Dr Warde is a radiation oncologist at Toronto’s Princess Margaret Hospital.

The international trial was coordinated by the NCIC Clinical Trials Group (CTG) and the Medical Research Council in the United Kingdom. The CTG is funded by the Canadian Cancer Society.

The clinical trial involved 1,205 patients whose disease, at the time of diagnosis, had spread to the area around the prostate gland or who had other high-risk factors, such as a high PSA level. About half the men were given the two therapies, while the other half received only hormone treatment. The study is one of the largest ever to test the effectiveness of this treatment method.

After seven years of follow-up, 74 per cent of men who had received the combination of radiation and hormone therapy were still alive, compared with 66 per cent of men who received hormone therapy alone. The researchers also found that the radiation therapy was tolerated well with no significant toxicity.

The results are very promising because they offer an important new treatment option,” says Dr Michael Wosnick, Vice-President of Research, Canadian Cancer Society. “They show that a substantial portion of these patients with high-risk disease would benefit from the addition of radiation therapy. And the fact that radiation therapy techniques have themselves improved greatly since the start of this trial, makes this option even more compelling to consider”.

The findings are published online November 3 in the The Lancet.

About 15 to 25 per cent of all newly diagnosed prostate cancer is locally advanced and therefore high risk. Dr Warde expects that the findings will lead to a change in the standard of care for this group of patients.

Prostate cancer is the most common cancer among Canadian men (excluding non-melanoma skin cancer). In 2011, an estimated 25,500 men will be diagnosed with prostate cancer and 4,100 will die of it.