Targeting a protein that helps tumours withstand chemotherapy could make cancer treatments more effective and less likely to cause side effects, research suggests.

British scientists have identified a molecule called Bcl-xl that blocks the self-destruct process which normally kills cells treated with chemotherapy drugs.

Drugs that suppress the molecule are already available. Tests showed that combining them with anti-cancer agents called taxanes proved far more effective than chemotherapy alone.

Study leader Stephen Taylor, Cancer Research UK Senior Research Fellow at the University of Manchester, said: “This important research shows us there’s potential to boost the cancer-fighting power of chemotherapy – and do more with less.

“This new combination could ‘soften-up’ cancer cells, making it easier for chemotherapy to deliver the final blow and destroy the tumour. And the good news is that drugs targeting Bcl-xL are already out there and being tested in clinical trials.

“Using this combination of drugs could improve treatment for patients receiving taxanes and lower their chemotherapy dose, which would also help to reduce side-effects.”

A major problem with chemotherapy drugs is the widespread damage they cause to healthy cells as well as tumours, leading to serious side effects including nausea, hair loss, and weakened immune systems.

Emma Smith, senior science information officer at Cancer Research UK, said: “Predicting which patients will benefit most from chemotherapy is essential if we’re going to make cancer treatments more effective and kinder.

“In cases where chemotherapy doesn’t seem to work straight away, we could add drugs that target Bcl-xL and hopefully see a real difference.

“It’s still early days for this research but, if the results are confirmed in clinical trials, it has the potential to improve treatment for thousands of cancer patients.”

The research is reported in the journal Cancer Cell.