Breast cancer screening is to be extended to older women under Department of Health plans that will improve the accuracy of diagnosis and save at least 1,000 lives a year.

Ministers intend to make an announcement in the summer, once arrangements have been put in place to train the extra staff needed to run the expanded service.

Research suggests that at least an extra 1,000 lives a year could be saved by extending the upper age limit for screening from 64 to 69 and by taking two X-rays of the breast from different angles instead of one. Women between the ages of 50 and 64 are currently invited for screening every three years.

The failure to include women aged over 64 in the breast screening programme has been cited as a clear examples of age discrimination in the NHS, by charities for the elderly. The chances of contracting breast cancer increase with age but, when the breast screening service began in 1988, research showed older women were reluctant to attend. They now see screening as more acceptable.

Three pilot studies in Leeds, Nottingham and Brighton have shown that extending the upper age limit is feasible and acceptable to women. In all three cities, the local health authorities have agreed to continue funding screening for older women, even though the pilot studies are complete.

Other research has shown that taking two X-rays of the breast from different angles instead of one, and getting two radiologists to examine them, increases the detection rate for small cancers by 40-50 per cent, which could prevent at least a further 500 deaths.

Early detection of small cancers is crucial in saving lives. Currently, in most parts of the country, only women attending for the first time - 27 per cent of the total in 1997-98 - receive two X-rays taken from different angles. Second and subsequent attenders receive only one.

More than 1.2 million women a year are screened for breast cancer, available on the NHS to all women aged over 50, but only those up to 64 are routinely recalled every three years. In 1997-98, almost 8,000 cancers were detected, 43 per cent of them too small to be felt by the human hand. Experts estimate that extending those women recalled up to the age of 69 and introducing double-view mammography will increase the £37m annual cost of the service by one-third.

Dr Robin Wilson, head of the breast screening unit at Nottingham City Hospital, said: "If the rumours of an extension to the programme are true this is to be welcomed. It would appear that the Health Department is convinced it is worthwhile."

A shortage of radiographers to do the screening and radiologists to read the X-rays is the main stumbling block to expansion of the service. A meeting of the Health Department's breast screening committee on 14 April chaired by Professor Michael Richards, the Government's cancer czar, agreed a project to set up training schemes for staff. It is estimated that 40 to 50 extra consultant radiologists and 150 to 200 extra radiographers will be needed. Breast screening is unpopular as a career choice because it is demanding, repetitive work and the penalties for missing a cancer are severe. One option being examined by Professor Richards' committee is to train radiographers, who are not medically qualified, to take over specific tasks that have been done by doctors.

Beyond the age of 70, benefits of screening diminish because, although more cancers are detected the women affected are more likely to die of something other than breast cancer, such as heart disease. In those circumstances, the cancer detected by screening may only cause anxiety.

A study published in the Journal of the American Medical Association last December suggested that screening 10,000 women every two years from age 69 to 79 would save only 10.8 deaths and add, on average, 2.5 days to a woman's life.

Dr Wilson said introducing double-view screening should take precedence over extending it to older people. "Some radiologists, myself included, would rather not extend the programme until we are providing the existing service to the best of our ability. Politically, I think the Government would like to do it all at the same time. But they are not prepared to make a decision until they come up with a solution to the staff shortage."

A spokeswoman for the Department of Health said: "The question of extending the programme to older women is a very interesting issue which is being examined by the department's breast screening committee."