Cancer is claiming the lives of thousands of cancer patients over the age of 75 sooner than it should, according to research by the National Cancer Intelligence Network.
The data suggest that up to 15,000 people a year who have been diagnosed with cancer are not living as long as they might.
Both western Europe and the US have higher cancer survival rates than the UK, possibly due to people in the UK being diagnosed later. Survival rates are calculated on the number of people alive five years after diagnosis.
North West Cancer Intelligence Service spokesman, Dr Tony Moran, said that there would be 15,000 fewer cancer deaths every year if the UK performed as well as western Europe regarding patients aged 75-84, and as well as the US for those aged 85-plus.
"The point is we don't know why this is happening," Dr Moran told the BBC. "Elderly cancer survival is an area which has been grossly neglected. It is crying out for research."