Blood test discovers cancer before cell mutation

CAIRO – 2 February 2018: A simple blood test can detect cancer in the very early stage, and even tell you where the tumor is located.

Scientists at Johns Hopkins Kimmel Cancer Center have developed a new test to diagnose a few amounts of cancer-specific DNA in blood and have used it to accurately identify more than half of 138 people with relatively early-stage colorectal, breast, lung and ovarian cancers.

The scientists have examined blood and tumor samples from 200 people with all stages of cancer in the U.S., Denmark and the Netherlands. Their results appear in the Aug. 16 issue of Science Translational Medicine.

“This study shows that identifying cancer early using DNA changes in the blood is feasible and that our high accuracy sequencing method is a promising approach to achieve this goal,” says Victor Velculescu, M.D., Ph.D., professor of oncology at the Johns Hopkins Kimmel Cancer Center.

To develop a cancer screening test that could be used to screen seemingly healthy people, scientists had to find new ways to spot DNA alterations that could be lurking in a person’s blood but had not been previously identified.

“The challenge was to develop a blood test that could predict the probable presence of cancer without knowing the genetic mutations present in a person’s tumor,” says Velculescu.

Colorectal and lung cancer are virtually symptomless in their earliest stages.

Velculescu says there is a chance these cells will mutate. In a small fraction of people, these changes will spur a blood cell to multiply faster than its neighboring cells, potentially leading to pre-leukemic conditions. However, most of the time, the blood-derived mutations are not cancer-initiating.

The program was still able to make diagnoses, demonstrating the potential of this method for the early detection of cancer, according to the researchers.