Pioneering cancer drug trials at a Bristol hospital could be scrapped because of a lack of volunteers.

Anastrozole has already been shown to reduce the risk of breast cancer victims developing the disease again.

However, researchers want to see if it can guard against cancer in women whose families have a history of the disease.

Breast surgeon Simon Cawthorn said: “If we don’t recruit enough women quickly then unfortunately the trial will fold and we won’t know the answer.”

Anastrozole works by reducing the levels of oestrogen, which is known to encourage breast tumour growth in some women.

Around 40 women have volunteered for the new trials at Frenchay but doctors say this is not enough.

Worldwide, 6,000 volunteers are needed for the trials.

“The problem is that women are worried about taking a tablet when they are fit and healthy,” Dr Cawthorn said.

“But this drug has been shown to be well tolerated with few side effects.”