Published in the British Journal of Cancer, the study by researchers at King's College London, predicts by 2040 there will be 1.2 million women in the UK living with breast cancer aged 65 and over (nearly four times today's number, 340,000).
The researchers estimate 73% of breast cancer survivors will be in this age group, compared with 59% today.
There Needs to Be a Change in the Care of Older PatientsCiarán Devane, Chief Executive of Macmillan Cancer Support, says in a statement released on Tuesday the National Health Service (NHS) has to take notice of these figures.
The NHS is "already struggling to provide adequate care for older breast cancer patients", says Devane.
"We need to change the way we care for older breast cancer patients now - so that we are prepared for such a dramatic increase in numbers," he urges.
Research shows that older women are far more likely to to be diagnosed later with advanced breast cancer, and they are also less likely to have breast conserving surgery compared to younger women.
Devane says: "Older people must be provided with the right treatment at the right time at the correct level of intensity."
"We can never assume that because a woman is older that she will not cope with surgery or that she is less interested in body image than a younger woman. It is our duty to ensure that every cancer patient has access to the best possible care."
Devane says we should not tolerate the present situation, where "too many cancer doctors are making assumptions based on age which often result in older women receiving inadequate care for their breast cancer".
The study results also suggest that the increase in breast cancer in the group aged 65 and over will be nearly double the rise for younger age groups.
In their press release, Macmillan urges "all cancer services to ensure that treatment decisions are based on objective assessment of patients as opposed to age-based assumptions".
The charity has teamed up with another charity, Age UK, and the Department of Health, to run five pilot tests of new models of care for older people. These are due to report results in December 2012.
Cancer ProjectionsAltogether, there are currently 2 million cancer survivors in the UK, a figure that has been growing by 3% a year in recent years.
The researchers used national cancer registry date for England to estimate cancer prevalence in the UK in 2009. They then used a computer model to make projections to 2040. They considered various scenarios of future incidence and survival, and their effects on cancer prevalence.
Breast cancer was one of the diseases they analyzed separately. They also looked at colorectal, lung, prostate, and all cancers combined (excluding non-melanoma skin cancer).
The projections show that assuming existing trends in incidence and survival continue, the number of cancer survivors in the UK will rise by around 1 million per decade from 2010 to 2040.
"Particularly large increases are anticipated in the oldest age groups, and in the number of long-term survivors. By 2040, almost a quarter of people aged at least 65 will be cancer survivors," write the authors.
They say such a substantial growth in the survivor population in the UK will have consequent demands on the health service.
"Plans must, therefore, be laid to ensure that the varied needs of cancer survivors can be met in the future," they conclude.
Written by Catharine Paddock PhD