Up to 2,000 lives a year could be saved if routine breast cancer screening was extended to older women, according to the charity Age Concern.
Widespread ignorance among older women also meant that they were not aware that they were at risk, despite the fact that two-thirds of deaths from the disease occur in women aged 65 or over.
Unlike their counterparts aged 50 to 64, older women are not invited for three-yearly screenings through the NHS breast screening programme, but they can request one.
However the survey of more than 1,000 women aged 65 showed that 70 per cent of women are unaware that they are entitled to request a screening, largely believing this right lies with younger women. Government figures show that less than half of one per cent of older women take up this entitlement every year.
Even those who do ask for a screening may be turned down - 2 per cent of respondents said they were told that screening was not available or were refused the service.
Age Concern's report, Not At My Age, also showed that 64 per cent of respondents considered themselves "not very much at risk" from breast cancer and more than a quarter [28 per cent] believed that they were at "no risk at all". More than half had never had a mammogram.
The director-general of Age Concern, Sally Greengross, said: "These findings paint a very bleak picture for older women. The current system does not adequately cater for those women most at risk. Up to 2,000 extra lives a year could be saved if screening were extended to older women. It is vital that they are made aware of their rights to the screening service. It is unacceptable that their ignorance may kill."
The charity is calling for the NHS breast screening programme to be extended so that all women over 65 are included in invitations for screening.
The shadow health minister, Henry McLeish, said Labour was concerned at the number of older women who were not being offered screening or being refused the service.
Breast cancer caused 5 per cent of all deaths in women, he said, and many could be prevented. "The Government is failing to meet its own targets for reducing the number of deaths from breast cancer."
But Julietta Patnick, national co-ordinator of the NHS breast screening programme, said that they had funded an educational drive with Age Concern to inform older women of their right to screening: "However I must emphasise we are not yet in a position to start including older women in the automatic call and recall system," she said.
"The programme prides itself on strict evaluation of new developments before they are fully incorporated. That is why we have welcomed the pilot programmes into increasing the screening age which are being set up in Wakefield and Brighton."
Breast cancer was also the subject of controversy after cancer specialists questioned the value of the Government's screening programme.
Professor Gordon McVie, scientific director of the Cancer Research Campaign, and Professor Michael Baum, a consultant surgeon at the Royal Marsden Hospital, London, said in September that the Government should reconsider the value for money of a programme that costs pounds 27m a year.Reuse content