Whole-genome sequencing could allow biopsy-free cancer tests

Genome sequencing identifies changes to chromosomes caused by cancer
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Researchers have found a way to use whole-genome sequencing to detect tumor DNA in the bloodstream, opening the door to a possible new screening test for cancer. But more research will be required to turn the findings into real-world applications.

The discovery came from scientists at the Johns Hopkins Kimmel Cancer Center in Baltimore, who published their findings last week in Science Translational Medicine.

The research involved testing blood from 10 late-stage colorectal and breast cancer patients and from healthy individuals to look for DNA "shed into the blood," Johns Hopkins University said in an announcement.

They found cancer-specific alternations in the chromosomes of all 10 of the cancer patients, then used bioinformatics to detect the changes "in a small fraction of the millions of DNA sequences contained in the blood sample," the university said. Such testing could allow cancer diagnoses without biopsies.

"This is proof of the principle that genome sequencing to identify chromosomal alterations may be a helpful tool in detecting cancer DNA directly in the blood and, potentially, other body fluids," Rebecca Leary, a postdoctoral fellow at Johns Hopkins, said in a statement. "But larger clinical trials will be needed to determine the best applications of this approach."

The next stage of research will focus on providing doctors information to guide decision-making on treatment options, Victor Velculescu, M.D., Ph.D., professor of oncology and co-director of John Hopkins' Cancer Biology Program said.

The researchers cautioned that early stage cancers might have less circulating DNA, making detection more challenging without more extensive sequencing. That becomes more feasible as the cost of sequencing tests falls, they said.

Earlier this fall, health technology company NantHealth and collaborators including Blue Shield of California, Verizon, Bank of America, Intel and Hewlett-Packard announced a new genomic supercomputer platform they said could analyze cancer genomes in seconds.

"We can't reduce the cost of care and improve outcomes in cancer if we don't have the capability to know the right treatment for the right patient before treatment begins," NantHealth founder Patrick Soon-Shiong said in a statement. "We needed a national supercomputing infrastructure that brings genomic medicine into clinical practice."

To learn more:
- read the study (subscription required)
- here's the announcement

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