Breast cancer vaccine is possible, says expert

Professor Valerie Beral of Oxford University, who leads the Million Women's Study into the causes of the disease, said her research had already proven beyond doubt that childbirth and the act of breastfeeding prevents breast cancer.

She wants scientists to look more closely at how they could mimic the hormones associated with childbirth and rearing in a bid to stamp out the disease, instead of trying to cure it once it has developed, as is mostly the case at present.

She pointed out that while death rates have been dramatically reduced by new drugs and earlier diagnosis, the number of women developing breast cancer and having to go through traumatic surgery and chemotherapy was rising.

She said it was impossible to return to an era where all women had babies and breastfed for longer periods of time, but added: "Why aren't we thinking of mimicking the effects of childbirth?

"We don't know how this happens and nobody is doing research on it. We should be looking at hormone production during late pregnancy and lactation."