Patches giving oestrogen through the skin could be an easy and safe alternative to the hormone therapies used to treat prostate cancer, according to new research published in the Lancet Oncology.
The Cancer Research UK funded study, run by researchers at Imperial College London, found that oestrogen patches, usually used to treat menopause symptoms in women, reduced levels of testosterone in men to a similar extent as the current hormone treatment, LHRHa injections. Many prostate cancers need the male hormone testosterone to grow. Using drugs to reduce testosterone in advanced stages of the disease can shrink the tumour or slow growth. In the 1960s this was done by using oestrogen tablets, but this caused heart and blood clotting side-effects for some men. Today, LHRHa injections are the main treatment for reducing testosterone but these can also cause serious side-effects including osteoporosis, bone fractures and diabetes. The trial compared the standard treatment – LHRHa injections – to oestrogen patches for men with locally advanced prostate cancer or prostate cancer that has spread, in order to test the benefits and side effects from the patches. A total of 254 men took part in the initial trial which showed patches appeared to suppress testosterone levels to a similar extent as LHRHa injections. Importantly the patches did not cause the same degree of heart and blood clotting problems caused by oestrogen tablets. After 12 months, the researchers also found that those having the LHRHa treatment had higher blood glucose and cholesterol levels, which can increase the risk of heart disease compared to men treated with patches. The initial trial has now been extended to look at 660 men to study the long-term effectiveness and side-effects of oestrogen patches.
