Twenty percent of women would consider having both their breasts removed to reduce their odds of developing cancer, according to a survey on Monday.

More than 1,500 women around the world were questioned in the poll about what choices they would make if told they were at high risk of the disease.

“It is extremely rare for women to undergo a double mastectomy for preventive reasons and, as an option, it is most relevant to women with a very strong family history of breast cancer,” said Dr Lesley Walker, of the charity Cancer Research UK.

Each year more than a million women worldwide are diagnosed with breast cancer. It accounts for 10 percent of all cancers and 23 percent of female cancer, according to the charity.

The poll, conducted by global market agency NOP World, involved women in Australia, Belgium, Brazil, Germany, Italy and Britain.

Having a family history of breast cancer, an early puberty, late Menopause, obesity and not having children can increase the risk of developing the illness.

Nearly half the women questioned said they were worried about developing breast cancer. In Britain about 60 percent admitted their fear of the illness.

Scientists at Cancer Research UK are enlisting 6,000 Postmenopausal women worldwide to take part in a trial to see if the drug anastrozole, or Arimidex made by AstraZeneca Plc, can prevent the disease.

The drug works by stopping the production of the female hormone oestrogen, which is an important cause of the illness.

“With over 30,000 post-menopausal women being diagnosed with breast cancer in the UK every year, it’s vital that we look for effective ways of preventing the disease,” said Professor Jack Cuzick, of Cancer Research UK, who is the lead researcher.