Older women are less likely to have breast cancer surgery than those who are younger, research suggests.
Experts are unsure of the exact reasons, although they say the findings cannot solely be explained by older women also having other illnesses.
They are conducting more research into whether patients choose not to have surgery or whether other factors - such as age discrimination in the NHS - play a role.
Researchers examined the records of more than 23,000 women with breast cancer diagnosed in the West Midlands, Yorkshire and the North East between 1997 and 2005.
They found that overall surgery rates dropped off with age, while women who had other illnesses were less likely to have surgery.
Even when other illnesses were taken into account, women who were older were less likely to have surgery.
More than 85 per cent of women aged 65 to 70 had surgery, but this fell to 70 per cent in those over 70 and 50 per cent among women over 80.
Older women from deprived economic areas were also less likely to have surgery.
The research comes after a report last week found older people are more likely to die of cancer because they receive less investigation of and treatment for their disease due to “age bias” in the NHS.
The King’s Fund and Cancer Research UK report found older people experience delays in having their case referred to a specialist and are less likely to undergo surgery.
They also have worse outcomes than younger patients.
Today’s findings were presented at the National Cancer Intelligence Network (NCIN) conference in London.
Katrina Lavelle, lead study author from Manchester University, said: “Previous research has shown that older women are less likely to have surgery for breast cancer compared with younger patients.
“Surgery to remove breast tumours is one of the most effective ways to treat this cancer so it’s important to get a better understanding of what lies behind these differences.”
Sarah Woolnough, Cancer Research UK’s director of policy, said: “This data means we need to ask serious questions about whether ageism exists in breast cancer surgery.
“Surgery is one of the most effective treatments for cancer so it’s crucial that as many women as possible are given the opportunity to have an operation to remove their breast tumour.
“We need to understand more about why the number of women having breast surgery drops off with age and ensure they’re not being denied potentially lifesaving treatment simply based on their age.
“The government and the surgical community must now urgently investigate why there are such marked variations by age and region.”