Men with prostate cancer who receive hormone therapy intermittently respond as well as those who receive it over a continuous time period, and enjoy quality-of-life benefits, according to a new Cancer Research UK-funded study* published in the New England Journal of Medicine today.
The researchers showed there was potential benefit for intermittent over continuous therapy in terms of fewer urinary problems and hot flushes, as well as improved libido and erectile function.
The international trial – which in the UK was funded by Cancer Research UK and led by The Institute of Cancer Research, London – included nearly 1,400 men for whom treatment with radiotherapy had not cleared their cancer. Around half the men had the new timing of intermittent hormone therapy and the other half had the standard, continuous hormone treatment.
Intermittent hormone therapy was delivered for eight months and then stopped. Doctors decided when to restart a patient’s treatment by testing for the level of prostate specific antigen (PSA) in their blood. If the PSA reached a certain level the hormone treatment began again and was given for another eight months. This cycle then continued.
Results showed that survival was not reduced when the intermittent therapy was given and that, for many men, side-effects were reduced and could lead to an improved quality of life. The men were followed for an average of around seven years.
UK chief investigator Professor David Dearnaley, professor of uro-oncology at The Institute of Cancer Research and honorary consultant at The Royal Marsden NHS Foundation Trust, said: “This large-scale trial has shown that periodically stopping men’s hormone therapy can give them fewer side-effects without reducing their chance of survival, and should lead to a change in clinical practice. More than 10,000 men are treated with potentially curative radiotherapy for prostate cancer each year in the UK and so our findings have the potential to benefit thousands of men.”
Cancer of the prostate depends on the male hormone testosterone for its growth. Hormone therapy for prostate cancer works by lowering the amount of testosterone in the body, helping to reduce the chance of an early prostate cancer coming back after radiotherapy. Or it can shrink an advanced prostate tumour down or slow its growth.
More than 40,800 men are diagnosed with prostate cancer in the UK every year. In 2010 around 10,700 men in the UK died from prostate cancer.
Kate Law, Cancer Research UK’s director of clinical research, said: “Results such as these highlight the value of clinical trials. Refining treatment to reduce side-effects and improve the outcome for patients remains the key goal. And being able to reduce the side-effects of prostate cancer treatments from currently available treatments offers patients and their doctors the potential of a new option of how their treatment is delivered.”
The study was led globally by the National Cancer Institute of Canada Clinical Trials Group and co-ordinated in the UK by The Institute of Cancer Research’s Clinical Trials and Statistics Unit.
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Crook, J. et al Intermittent Androgen Suppression for Rising PSA after Radiation. New England Journal of Medicine, 2012.