BLOOD TEST SPOTS TUMOR-DERIVED DNA IN PEOPLE WITH EARLY-STAGE CANCER
Updated: Jun 16, 2021
Scientists at the Johns Hopkins Kimmel Cancer Center have used this to accurately identify more than half of 138 people with early-stage colorectal, breast, lung and ovarian cancers.
Velculescu, Phallen and team not only ruled out the possibility of reading germline mutations as well as blood-derived mutations to reduce false positives but also included blood samples from 200 patients with breast, lung, ovarian and colorectal cancer, so as to ensure wide applicability.
The blood test uses a type of “targeted error correction sequencing” based on deep sequencing and reads each chemical code in DNA 30,000 times to spots tiny amounts of cancer-specific DNA in blood.
The test screens the samples for mutations within 58 genes widely linked to various cancers. Scientists were able to detect 86 of 138 (62 percent) stage I and II cancers.
They found none of the cancer-derived mutations among blood samples of 44 healthy individuals.
Populations that could benefit most from such a DNA-based blood test include those at high risk for cancer including smokers (wherein standard teste s often lead to false positives)— and women with hereditary mutations for breast and ovarian cancer within BRCA1 and BRCA2 genes.
- Sudiksha Gupta