UK bowel cancer trial Tracc could help patients avoid chemotherapy with new blood test

The study has the potential to "revolutionise treatment for operable bowel cancer within five to eight years". Photo / 123RF

Countless cancer patients could soon avoid brutal chemotherapy thanks to a ground-breaking new blood test.

A major bowel cancer trial in the UK known as Tracc, tracking mutations in cell-free DNA to predict relapse in early colorectal cancer, is examining whether the test, which can pick up traces of cancer cells, can accurately see if surgery has removed a patient’s entire tumour.

That would mean chemotherapy would be unnecessary.

With around 50 per cent of people with Stage 3 bowel cancer able to be successfully cured of the disease with surgery alone, chemotherapy is often over-treating patients who don’t actually need it in the first place.

Invasive bowel cancer, as seen through a microscope. Photo / news.com.au

At the moment, bowel cancer is typically treated with surgery first, followed by chemo in order to remove any lingering cancer cells. However, bowel cancer chemotherapy can cause a range of unpleasant side effects.

The study is being carried out at London’s Royal Marsden Hospital, and according to its website, it could help save patients from “toxicity, with the potential for huge cost savings” for England’s National Health Service (NHS).

“So far, doctors have been unable to precisely advise each patient on whether they are likely to benefit from chemotherapy post-surgery,” the website states.

“Unfortunately, chemotherapy produces side effects that can include mouth ulcers, loss of appetite, diarrhoea, sore hands and feet, brittle hair and nails. More serious and troublesome side effects include damage to the nerves in the hands and feet, life-threatening infections, cardiac chest pain and blood clots.

“Sometimes side effects can be life-long, and patients report them to be debilitating, cause anxiety, impact close relationships and impair their ability to work.

“By reducing the use of unnecessary chemotherapy through our proposed precise approach, the patient’s quality of life will be greatly improved while also significantly saving NHS resources.”

It said the study had the potential to “revolutionise treatment for operable bowel cancer within five to eight years”.

While traces of cancer in the blood – known as circulating tumour DNA – are normally undetectable on scans, the new blood test is now able to pick them up, which is why the test has been hailed as such a breakthrough.

Dr Naureen Starling, principal investigator on the Tracc trial, said the tests could vastly improve patients’ quality of life.

“Half of patients with Stage 3 bowel cancer are cured by surgery alone, so we are over-treating a large proportion of patients,” she said.

Eliminating the need for aggressive chemo, she said, was “good for the patient, it’s good for the health service, it’s good for cost savings within the [health system] – that would be a win-win”.

The test was developed by US firm Guardant Health, with samples from the hundreds of UK patients involved in the trial being sent to labs in California for testing, which takes around a fortnight before results are available.