OXFORD University scientists have found a way of delivering drugs to treat life-threatening cancers that have spread to the brain, according to new research.

The study in mice and tissue samples used a protein called TNF that can track sites in the brain where cancer has spread by recognising a marker found only on tumour blood vessels. The scientists found that TNF homes in on these sites and temporarily opens the blood-brain barrier (BBB), allowing drugs to pass from the blood system into the tumour.

The BBB prevents dangerous particles entering the brain. Study author Dr Nicola Sibson, a Cancer Research UK-funded scientist at Oxford University, said: “Treatments lose effectiveness when cancer spreads to the brain – drugs are prevented from getting to the tumour by the BBB.

“Attempts have been made to open the BBB but they’re either not specific enough to open the BBB only at the tumour site or not effective enough to allow the drug across to kill the cancer.”