Scientists from Canada and the UK have found evidence that combining hormone therapy with radiotherapy improves survival among prostate cancer patients.

The study, published by The Lancet, looked at the effects of combining radiotherapy with androgen deprivation therapy (ADT), which reduces the level of male hormones such as testosterone.

The trial involved patients with prostate cancer that had begun to spread to nearby tissues, but which hadn't spread to other parts of the body - so-called locally advanced prostate cancer.

The researchers found that those who were given radiotherapy on top of ADT survived for longer than those who were given ADT alone.

Commenting on the findings, Dr Matthew R Cooperberg from the University of California, said the study provided the "strongest evidence to date" that ADT alone is not adequate to treat such high-risk prostate cancer.

But while it is clear that a combination approach is needed, further research must be carried out to establish whether the best strategy involves radiotherapy and ADT or a combination of surgery followed by radiotherapy, he added.

The research was led Dr Padraig Warde from the Princess Margaret Hospital in Toronto, Matthew R Sydes from London's MRC Clinical Trials Unit, and Dr Malcolm Mason from the Cardiff University School of Medicine.

Their study involved 1,205 prostate cancer patients who were randomly assigned to receive either a combination of ADT and radiotherapy, or ADT alone.

After a follow-up period of six years, 320 of the patients had died. Of these, 175 were in the ADT-only group and 145 were in the combined ADT and radiotherapy group.

The researchers calculated that the addition of radiotherapy to ADT improved survival rates after seven years, with 74 per cent of patients in the combined group surviving compared with only 66 per cent in the ADT group.

The team found that very few patients suffered serious side effects as a result of either treatment strategy.

The authors wrote: "This trial provides convincing evidence that local control of disease in the prostate improves survival in patients with locally advanced prostate cancer."

They concluded: "Our findings suggest that the benefits of the combination of ADT and radiotherapy should be discussed with all patients considering a curative treatment approach."

Professor Tim Maughan, a Cancer Research UK funded radiotherapy specialist, said: "This is a very significant piece of research, which reinforces the importance of radiotherapy as a cancer treatment. The study showed that by adding radiotherapy to standard hormonal treatment for this group of prostate cancer patients, deaths from locally advanced prostate cancer could be significantly reduced.

"Treating more prostate cancer patients with radiotherapy could save hundreds of lives each year in the UK. We know that modern radiotherapy techniques are very precise and are able to target tumours very effectively, while minimising damage to surrounding healthy tissue.

"It's encouraging to note that this study confirmed that additional side-effects resulting from adding radiotherapy to standard prostate cancer treatment were minimal."

Source: CRUK