Estrogen Patches May Offer New Treatment Option for Prostate Cancer Patients
Risk of side effects reduced compared with hormone injections (Mar. 4)
Patches giving estrogen 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 Lancet Oncology.
The study, funded by Cancer Research UK, found that estrogen patches, usually used to treat menopause symptoms in women, reduced levels of testosterone in men to a similar extent as the current hormone treatment — injections of luteinizing hormone-releasing hormone analogue (LHRHa).
Many prostate cancers need the male hormone testosterone to grow, the researchers say. Using drugs to reduce testosterone in advanced stages of the disease can shrink the tumor or slow growth. In the 1960s, this was done by using estrogen tablets, but this caused heart and blood-clotting side effects in some men. Now, LHRHa injections are the main treatment for reducing testosterone, but these injections may also cause serious side effects, including osteoporosis, bone fractures, and diabetes.
The new trial compared the standard treatment — LHRHa injections — with estrogen patches in 254 men with locally advanced prostate cancer or prostate cancer that had metastasized.
The patches appeared to suppress testosterone levels to a degree similar to that of LHRHa injections. Importantly, the patches did not cause the same degree of heart and blood-clotting problems caused by estrogen tablets.
After 12 months, the researchers also found that the men receiving the LHRHa injections had higher blood glucose and cholesterol levels, which can increase the risk of heart disease, compared with the men treated with patches.
Study author Dr. Ruth Langley said: “These promising new findings suggest that we might be able to use estrogen patches or an estrogen gel to treat prostate cancer without significantly increasing the risk of heart disease and stroke. We think the reason oral estrogen caused these side effects is because the estrogen reached the liver in high concentrations straight from the stomach, whereas if the estrogen can be absorbed through the skin the effect on the liver is avoided.”
Source: Cancer Research UK; March 4, 2013.