Scientists at the Institute of Cancer Research in London have published a study in Science Translational Medicine about a blood test that may be able to save lives by finding cancers that have started to grow again after treatment, reports BBC News.

The study followed 55 breast cancer patients who were at high risk of relapse because of the size of their tumours at the time they were diagnosed and removed. Tests found traces of breast cancer eight months before doctors would normally have noticed, although experts have said it would be some time before developing a test that could be used in hospitals.

The scientists analysed the mutated DNA of the tumour and then continued to search the blood for those mutations. Fifteen women relapsed and the blood test gave advanced warning of 12 of them. The hope is that detecting cancer earlier means treatments including chemotherapy can start sooner and improve the chances of survival.

Dr Nick Peel, from Cancer Research UK, said: "Finding less invasive ways of diagnosing and monitoring cancer is really important and blood samples have emerged as one possible way of gathering crucial information about a patient's disease by fishing for fragments of tumour DNA or rogue cancer cells released into their bloodstream. But there is some way to go before this could be developed into a test that doctors could use routinely, and doing so is never simple."

Lucie Prothero, who specialises in cancer cases within the Penningtons Manches’ clinical negligence team, comments: “Any developments which mean that recurrence of cancer can be caught earlier are welcome news. Every day we work with clients who are suffering with cancer that has spread and who have a poor long-term prognosis. Anything that helps to monitor at risk breast cancer sufferers and leads to an earlier diagnosis of recurrence will help to improve patients’ prospects of beating the disease.”