Cambridge study finds hot flush treatment has anti-breast cancer activity

A low dose of megestrol acetate (a synthetic version of progesterone) has already been proven as a treatment to help patients manage hot flushes associated with anti-oestrogen breast cancer therapies, and so could help them continue taking their treatment. The PIONEER trial, supported by NIHR Cambridge BRC, has now shown that the addition of low dose megestrol to such treatment may also have a direct anti-cancer effect.

Around three-quarters of all breast cancers are ER-positive. This means the tumours are abundant in a molecule known as an oestrogen receptor, "feeding" on the oestrogen circulating in the body. These women are usually offered anti-oestrogens, medication that reduces level of oestrogen and hence deprives the cancer of oestrogen and inhibits its growth. However, reducing oestrogen levels can bring on menopause-like symptoms, including hot flushes, joint and muscle pain, and potential bone loss.

In the PIONEER trial, post-menopausal women with ER-positive cancers were treated with an anti-oestrogen with or without the progesterone mimic, megestrol. After two weeks of treatment, those that received the combination saw a greater decrease in tumour growth rates compared to those treated with an anti-oestrogen only. 

Full article: NIHR Cambridge Biomedical Research Centre