Researchers from Oxford and Ulster universities say low oxygen levels in tumours is a key reason why radiotherapy and drugs fail.
They hope to develop a drink, rich in oxygen micro-bubbles, that could deliver oxygen to cancerous masses.
But they say their work is just beginning.
Scientists have noted for years that many cancerous tissues have less oxygen than their healthy counterparts.
One reason thought to behind this is that cancers grow rapidly and their blood supply fails to keep up – leaving tumours with torturous, poorly-formed blood vessels that don’t deliver oxygen-rich blood as well.
Prof Eleanor Stride, from Oxford University, says the lack of oxygen makes cancer cells “go into survival mode” making them more hardy and therefore less responsive to radiotherapy and drugs.
This is a particular problem for hard-to-treat cancers such as tumours of the pancreas, she says.
The team has already found that injecting oxygen in mice with cancer and then giving them chemotherapy leads to more successful treatments.
They recently carried out a small-scale trial of an oxygen-rich drink in mice.
The next stage is to repeat the mice experiments in much larger numbers, before human trials are considered.
But Prof Stride says: “I wouldn’t suggest people rush out to buy any drinks claiming to be rich in oxygen.
“We are at an early stage – there is still a lot of engineering and thought that will have to go into this to make it work.”
Dr Iain Foulkes, at charity Cancer Research UK, added: “Prof Stride and her team are thinking outside the box and this is just the sort of innovation we want to spark through our pioneer awards scheme.
“By being bold we aim to make a difference.”