NHS England has said that patients with cancer will be offered a rapid new test to help decide whether to go ahead with treatment, opt for a lower dose or use a different method of tackling tumours.

Although most patients undergoing chemotherapy do not suffer sever side effects, a small number taking certain drugs called fluoropyrimidines (5-FU and capecitabine) can suffer nausea, vomiting, diarrhoea, breathlessness and severe skin reactions and, in rare cases, the reaction can be fatal.

The new blood test detects a particular form of a gene which means that someone is less able to break down chemotherapy drugs in their body. As many as 40 per cent of those who get tested are expected to benefit from starting on a lower dose, or have a different treatment altogether.

NHS England has said that the test, which was only previously available at a small number of hospitals, will now be funded across the country.

Peter Johnson, NHS England National Clinical Director for Cancer, said: “Cancer survival rates are at a record high but the condition still causes huge suffering for millions of patients and their loved ones every year. This test can help us to treat people with cancer as safely as possible, at what has been and continues to be an exceptionally a difficult time for millions of us.

“The number of people having their cancer care with the NHS is back to levels we saw before Covid-19, with nearly 350,000 having treatment since the first peak, and as the NHS continues to prioritise essential cancer care, this latest innovation is another important tool to ensure people in England get the best possible treatment.”

The NHS also secured a landmark £160 million deal for covid-friendly  cancer drugs which do not hit patients’ immune systems so hard or reduce the number of hospital trips they need to make for treatment.