Drugs used to prevent bone loss in osteoporosis could help cut breast cancer deaths, say researchers from Oxford University. A study of 18,766 women, published in the Lancet, found that taking the bone strengthening drug stopped secondary tumours growing in the bone.
Described as one of them important breakthroughs in breast cancer treatment for a decade, health experts believe it could save 1,000 lives a year in the UK.
Bisphosphonates, which are normally taken to prevent bone loss in osteoporosis, are able to "starve" any cancerous cells which spread to the bone and prevent them from growing.
The Early Breast Cancer Trialists' Collaborative Group, co-ordinated by the University of Oxford, studied data from 26 separate trials of women who took bisphosphonates for up to five years after a cancer was removed from their breast.
They found a 28% reduction in cancers detected in the bone, but only in post-menopausal women. Overall, deaths were cut by 18% over the 10 years after they were first diagnosed.
Prof Rob Coleman, who analysed the data, told the BBC News website: "The magnitude of the benefit on mortality was bigger than we had anticipated - a risk reduction of 18% is quite sizeable."
However, the drugs are not currently available for this purpose on the NHS and are only licensed for use where a cancer has been discovered in the bone.
Prof Coleman added: "The access issue is an important one. It would be a great shame if the systems we have to work with prove to be a block.
"Normally the problem is we can't afford [a new drug] but this is peanuts, it's that there isn't a mechanism for this and there needs to be."
Lady Morgan, chief executive of Breast Cancer Now, said: "We believe that this is one of the most important steps forward in breast cancer treatment since the introduction of Herceptin over 10 years ago, but this time we're talking about a few pence rather than thousands of pounds, and millions saved by the NHS.
"However, despite costing less than five pence a day per patient, this treatment runs the risk of 'sitting on the shelf', and not realising its full benefit for the 34,000 [post-menopausal] women who could be eligible to take it each year."
Earlier this week an NHS cancer task force called for new guidelines to be produced on bisphosphonates.