The research, by the charity Age Concern, found that 89% of women over 70 think that breast cancer is not a risk.

Only 11% know that they are more at risk than any other age group.

The onus now must be on the government and breast cancer charities to specifically target the over 70s

Gordon Lishman, Age Concern

In fact, women in this age group are twice as likely as younger women to die from breast cancer.

Year 2000 figures show that 40% of all breast cancers occur in women over 70.

It has been estimated 1,500 lives could be saved each year through early detection and treatment if women over 70 were screened.

Extremely disturbing

Gordon Lishman, Age Concern director general, said: "It is extremely disturbing that women in the very age group most at risk from this devastating disease should be least aware of the danger they face.

Gordon Lishman called for government action

"The onus now must be on the government and breast cancer charities to specifically target the over 70s in their campaigning and policy advances.

"It is vital that we create a real sense of urgency to tackle this wholly avoidable misconception."

Women currently stop being invited for screening at 65.

The government announced in the NHS Plan that the upper age limit will be increased to 70.

However, this will not come into effect until 2004.

Screening

The research also showed that 85% of women over 70 have not been screened in the last three years.

Older women under-estimate, and younger women over-estimate, their risk

Delyth Morgan, Breakthrough Breast Cancer

Mr Lishman said: "Various campaigns to raise awareness of breast cancer have been enormously successful amongst younger women and has without doubt saved lives.

"The real challenge now is to duplicate that success amongst older women."

Delyth Morgan of Breakthrough Breast Cancer said: "Misconceptions about risk do exist.

"Older women under-estimate, and younger women over-estimate, their risk.

"Women also appear to over-estimate the importance of inheritance as a risk factor and under-estimate lifestyle and environmental factors.

"Breakthrough welcomes the extension of routine screening for women over 65.

"This extension will help older women be aware of their risk.

"Previously, the fact that they were told they would no longer be called for screening added to their false sense of security."

Open-ended system

Professor Ian Fentiman, of Guy's Hospital, called for an open-ended system of screening starting at the age of 50.

"We have stereotyped older women, saying that somehow as soon as they reach the age of 70 they are all decrepit, whereas most of them are leading perfectly normal lives."

However, Julietta Patnick, national coordinator for the NHS breast cancer screening programme, said older women were much less likely to respond to invitations for screening.

"When women get into their seventies and eighties they have other health problems and sometimes breast screening is not always appropriate for them.

"You have to treat women much more as individuals as they get older, whereas for younger women we are much more confident of the benefit."

In 1998, 7,372 women over 65 died from breast cancer, compared with 3,021 in the 50-64 year age group.