New blood test may limit chemo treatment for cancer patients

About 1,600 bowel cancer patients in the UK are set to take part in a study over four years, which could affect the way thousands of patients with the disease are treated.

The study, which involves the Royal Marsden NHS Foundation Trust in London, aims to predict relapse in colorectal cancer.

While most stage 3 bowel cancer patients are offered post-operative chemotherapy, doctors say it may be unnecessary for many patients with the disease, and half of patients are treated by surgery alone.

Between 30-50pc of stage 3 colorectal cancer patients relapse from microscopic minimal residual disease (MRD), so high-risk bowel patients are recommended chemotherapy after surgery to help reduce the risk of future recurrence.

It is hoped the trialled blood test will prevent the need for chemotherapy by detecting microscopic traces of cancer in the bloodstream that would be invisible on a scan.

The presence of these markers indicates whether the patient has been successfully treated by their surgery or not.

The principal investigator on the trial, Dr Naureen Starling, said: “Half of patients with stage 3 bowel cancer are cured by surgery alone, so we are over-treating a large proportion of patients.”

The doctor added that sparing cancer patients from unnecessary chemotherapy is: “Good for the patient, it’s good for the health service, it’s good for cost savings within the NHS. That would be a win-win.”

The trial uses a test created by US company Guardant Health.

Samples are sent to labs in California for analysis and results are returned two weeks later.

The trial will examine the survival rates after three years for patients whose treatment was guided by the blood test, and patients who had intravenous chemotherapy. Similar trials are under way in the UK for patients with lung and breast cancer. (© Independent News Service)