Women who have a relative who has had breast cancer are more likely to develop the disease, but doctors say the risk is still minimal.

Oxford researchers have found that women whose mothers, sisters or aunts have had the illness have a one-in-eight chance of being diagnosed themselves.

Their risk is nearly twice that of women with no family history of breast cancer, who have a one-in-13 chance of diagnosis.

Prof Valerie Beral and her colleagues at the Imperial Cancer Research Fund's cancer epidemiology unit, at the Churchill Hospital, Headington, also discovered that the risk rose to one-in-five for women who had two close relatives with breast cancer.

Despite the findings, Prof Beral said: "It shows that just because a relative has the disease, it is not certain by any means that you will get it."

Information from 52 studies across the world was used to work out the risk factors, including data from 60,000 breast cancer victims and 100,000 women without the disease.

Scientists also crushed the common myth that women with a family history of the disease are more susceptible to breast cancer at an early age.

The research, published in today's Lancet medical journal, showed that the majority are actually diagnosed after their 50th birthday.

Earlier this month, the Oxford Mail revealed that women in Oxfordshire who wanted to know if they were at high risk from breast cancer has increased four-fold in two years.

Experts at the Churchill Hospital said more patients were inquiring about genetic testing after their relatives developed the disease.