Cancer surgeons are facing "an impossibly difficult question" of whether to operate or not during the coronavirus outbreak.
The head of the Royal College of Surgeons of Edinburgh (RCSEd) is calling for "Covid-free hubs" to ensure life-saving procedures continue to go ahead.
It comes a a leading charity warns cancer must not become "the forgotten 'C'" during the Covid-19 pandemic.
The RCSEd - which represents 15,000 members across the UK - found a third of its members who carry out cancer operations have stopped surgeries during the crisis.
The group found 87 per cent of cancer surgeons had reduced the number of procedures taking place despite Public Health England (PHE) guidance to introduce Covid-free hubs so such operations could continue.
RCSEd president Professor Michael Griffin said: "Major surgeries on certain cancer types have very significant risks attached to them and performing them in an environment where coronavirus is present could potentially outweigh the risk of delaying surgery."
He added the main issue is having "no uniform approach" across the UK on deciding whether to operate or not".
The Government has repeatedly urged the public to continue to use the NHS if they need to seek medical assistance whether it's related to coronavirus or not.
The RCSEd findings come as cancer charity Macmillan launched an emergency appeal to support cancer nurses called to the coronavirus frontline.
Macmillan says "hundreds" of cancer nurses and healthcare professionals are working against the Covid-19 outbreak.
The charity has pledged a £5 million "coronavirus response fund" to help meet emerging needs and fund other initiatives. It is also launching "virtual services" to support the 3 million people living with cancer in the UK.
Lynda Thomas, CEO at Macmillan Cancer Support said "it is critical" cancer patients are not forgotten.
"For people with cancer right now, these can be terrifying times; isolating at home, separated from loved ones and suddenly being told the treatment and surgery that had felt like their lifeline could be changed or postponed."
A video appeal has been released by the charity to help raise funds during the outbreak.
Celebrities including Fearne Cotton, Johnny Vegas, and Martin Clunes have all given their backing to the initiative.
Johnny Vegas, who features in the appeal film, said: "My family and I have seen first-hand how Macmillan Cancer Support makes a world of difference to people in their darkest hours.
"Right now, Macmillan needs all the help it can get to continue to be there for everyone who needs them and support our beloved NHS at this critical time."
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