Cancer caught early with blood test

A UNIVERSAL cancer test that can detect tumours 10 years before they become dangerous is being developed, scientists have announced.

Researchers told the world’s largest oncology conference in Chicago they had successfully trialled a simple blood test on more than 120 patients with breast, lung or prostate cancers.

Doctors currently rely on scans and biopsies to detect cancer which are usually only carried out when a patient feels unwell and some procedures come with the risks of surgery.

However, so-called “liquid biopsies” are risk-free and repeatable procedures that work by detecting DNA fragments of tumours in the blood. These would particularly benefit patients with cancers that have poor survival rates because they are often detected at a late stage, such as lung, pancreatic and ovarian. They also promise to detect the size and location of tumours.

Medics have said a universal screening test would reduce cancer mortality by 90 per cent and experts predict that rudimentary tests will soon be available for as little as £155.

Dr Nicholas Turner, of the Institute of Cancer Research and London’s Royal Marsden Hospital, said: “The potential is absolutely clear and very exciting. If we could identify patients with, say, pancreatic or lung cancer at the point they could all have surgery, you could potentially transform management of the disease and survival for patients.”

The trial, funded in part by Bill Gates and Amazon founder Jeff Bezos, found that in 89 per cent of patients at least one genetic change detected in the tumour was also detected in the blood. In breast cancer patients where their cancer had spread, it was 97 per cent.

Significantly, the team at the Memorial Sloan Kettering Cancer Centre in New York could detect three quarters of “actionable” mutations – that can be matched to an existing targeted therapy – in the blood.

The American Society of Clinical Oncology meeting also heard results from a separate study at Johns Hopkins University where blood tests were able to detect traces of pancreatic tumours in 50 per cent of patients with the disease.

The ultimate aim is to develop a test that can identify the presence of a broad range of cancers as well as indicating what treatments would be most effective in shrinking them. The new Parsortix system, developed by British firm Angle, for example, is able to predict which patients with colon cancer will respond to standard treatments.

With slow-progressing diseases such as prostate cancer, the technology could give doctors 10 years’ warning of potentially dangerous tumours.

However, while scientists know the genetic signatures for 90 per cent of common cancers, they have not yet established a robust system of ruling out false positives or accounting for the different ways the mutated tumour genes are expressed in different patients.