Scientists are closer to a blood test to detect eight types of cancer

The aim of the test, CancerSEEK is called, is to catch the disease early and save lives. In a study Thursday in the journal Science, Johns Hopkins University scientists looked to see how well their experimental test detected cancer in people already known to have the disease. The blood tests found about 70 percent of eight common types of cancer in the 1,005 patients. The rates varied depending on the type — lower for breast tumors but high for ovarian, liver and pancreatic ones.

This blood test could cost less than $500, which is comparable to or lower than other screening tests, such as a colonoscopy, according to the study. The study was funded by many foundations, research groups, and grants, while many of the study authors have ties to biotechnology or pharmaceutical companies, as well as patents.

As a tumour grows, cancerous cells within it change, reproduce and die. When cancer cells die, they can also release DNA and other fragments that get into blood. CancerSEEK is described as a ‘liquid biopsy’ and analyses a patient’s blood sample for traces of that cancer DNA and through identifying which genes and mutations are most active, it can identify the type of cancer and the best treatment.

“It will take a long time, we need to prove that it does work,” said Professor Richard Marais of Cancer Research UK. “They (Johns Hopkins University) looked at healthy people. If you have a cold or flu or some other underlying condition, how will that affect the test?”

“But I look forward to a time in 10 years, where we all go to the pharmacy, we buy our shampoo, we give a blood test and we get on with our lives. And the NHS [in the UK] is spending more money diagnosing than treating disease. If we can diagnose it early, then we can treat it sooner and then we can save people’s lives.”

While experts around the world are praising the test as an exciting development, they say more research needs to be done.

Dr. Len Lichtenfeld, deputy chief medical officer of the American Cancer Society, was encouraged that the test did well on cancers that lack screening tests now. If a blood test could find 98 percent of ovarian cancers at an early stage, as these early results suggest, “that would be a significant advance,” he said.

But he cautioned: “We have a long way to go to demonstrate its effectiveness as a screening test.”

Companies have been pouring money into developing liquid biopsies. One startup, Grail Bio, has raised over $1 billion in pursuit of a single blood test for many cancers.