Stanford scientists have shown that it's possible to simultaneously screen for dozens of cancer-associated mutations from a single blood sample using a multiple-gene panel. The research is published today in the Journal of Clinical Oncology (subscription required).
As I describe in my release:
Gene panels allow researchers to learn the sequences of several genes simultaneously from a single blood sample. It stands to reason that screening for mutations in just a few select genes is quicker, easier and cheaper than whole-genome sequencing. The technique usually focuses on fewer than 100 of the approximately 21,000 human genes. But until now, few studies have investigated whether homing in on a pre-determined panel of suspects can actually help people.
The researchers, medical oncologists and geneticists James Ford, MD and Allison Kurian, MD, used a customized 42-gene panel to investigate the presence of cancer-associated mutations in 198 women with a family or personal history of breast or other cancers. The women had been referred to Stanford's Clinical Cancer Genetics Program between 2002 and 2012 to undergo screening for mutations in their BRCA1 or BRCA2 genes. They found that the panel was a useful way to quickly screen and identify other cancer-associated mutations in women who did not have a BRCA1/2 mutation. From our release:
Of the 198 women, 57 carried BRCA1/2 mutations. Ford and Kurian found that 14 of the 141 women without a BRCA1/2 mutation had clinically actionable mutations in one of the 42 genes assessed by the panel. (An actionable mutation is a genetic variation correlated strongly enough to an increase in risk that clinicians would recommend a change in routine care — such as increased screening — for carriers.)
Eleven of the 14 women were reachable by telephone, and 10 accepted a follow-up appointment with a genetic counselor and an oncologist to discuss the new findings. The family members of one woman, who had died since giving her blood sample, also accepted counseling. Six participants were advised to schedule annual breast MRIs, and six were advised to have regular screens for gastrointestinal cancers; many patients received more than one new recommendation.
One woman, with a history of both breast and endometrial cancer, learned she had a mutation that causes Lynch syndrome, a condition that increases the risk of many types of cancers. As a result, she had her ovaries removed and underwent a colonoscopy, which identified an early precancerous polyp for removal.
The study shows that gene panels can be a useful tool that can change clinical recommendations for individual patients. It also indicates that patients are willing and eager to receive such information. As Ford explains in the release:
Gene panels offer a middle ground between sequencing just a single gene like BRCA1 that we are certain is involved in disease risk, and sequencing every gene in the genome. It’s a focused approach that should allow us to capture the most relevant information.
Previously: Whole genome sequencing: the known knowns and the unknown unknowns, Assessing the challenges and opportunities when bringing whole-genome sequencing to the bedside and Blood will tell: In Stanford study tiny bits of circulating tumor DNA betray hidden cancers.