Taking a potential new breast cancer treatment from the lab to the clinic.

Two years ago Dr Jason Carroll made news through his possible explanation into why women whose breast cancer carried both oestrogen and progesterone receptors did better than those who carried only the oestrogen receptor even with the same treatment.

The original study found that signals sent through the progesterone receptors slowed down the growth of the tumour. The team tested progesterone based therapies on mice and had very positive results. By treating the mice with drugs that cut off oestrogen and a dose of progesterone to slow tumour growth they were able to provide a double attack.

Now two years later three clinical trials are set to test this theory in people. The trial led by Carroll and his team will focus on post-menopausal women. The idea was to try the combination of oestrogen-blocking drug and progesterone as the first therapy women receive.

“A clinical trial from Brazil showed that around 40% of women whose cancer had stopped responding to standard oestrogen-blocking therapies, including tamoxifen and anastrozole, still responded to a man-made progesterone called megestrol acetate,” says Carroll.

Carroll went on to explain that “Because the drugs we want to test have been used by doctors for years for a variety of reasons, including in the treatment of late stage metastatic breast cancer, we know they are safe and what doses to use them at. Plus they have the benefit of being cheap,”

They plan to test the combination drugs in a gap that exists between diagnosis and surgery.

“What happens is there’s normally a few weeks’ wait between a woman having a biopsy and then having surgery to remove her tumour. In our trial, we’re going to ask women to take the combination of an oestrogen-blocking drug – in our case anastrozole – and the man-made progesterone (megestrol acetate) during this wait. Then we can study the biopsy sample and a sample of the tumour removed during surgery to see the effects of the combination treatment on the cancer cells.”

To read more about these clinical trials please visit Cancer Research UK