Nav: Home

Tumor gene test results can differ in same patients

December 15, 2016

A preliminary study comparing two commercially available, next-generation genetic sequencing tests in the same cancer patients shows results can differ widely. The findings are reported Dec. 15 in JAMA Oncology.

Genetic testing is used in thousands of cancer patients each year.

Clinical testing for cancer-associated genetic alterations is growing because of the need to better match cancer patients with effective therapies, the authors note. They explained that tests are done to target drug selection to tumor characteristics. Test reports also sometimes pull up research trials in which the patient might consider participating.

However, according to the researchers, little information is available about how closely the output of various sequencing assays match up for an individual's case.

The research was led by Dr. Tony Blau, a faculty member in the Department of Medicine at the University of Washington School of Medicine, and investigators at the UW Medicine Center for Cancer Innovation. Blau is also with the UW Medicine Institute for Stem Cell and Regenerative Medicine Research.

In their study, nine patients from a community cancer-care practice received reports from two testing platforms: FoundationOne, from FoundationMedicine, and The Guardant360, from Guardant Health. FoundationOne tests tumor samples to characterize 315 cancer-associated genes and 28 other genes prone to rearrangement. The Guardant360 takes blood samples to examine the cell-free DNA that dying tumor cells release into the bloodstream of cancer patients. It sequences 70 genes.

In one patient, neither test found any genetic alterations. The remaining patients as a group had 45 alterations, just 10 of which (22 percent) were discovered by both platforms. For two patients, no results matched between the two reports. The test reports of 8 patients with identified alterations mentioned a total of 36 possible treatment drugs. Only 9 drugs were called out by both tests for the same patients. For 5 patients, there was no overlap between the suggested drugs.

"Our findings indicate that the output from genetic testing can differ markedly depending on which test is applied," the researchers noted. Because both types of test are performed annually on many cancer patients, they added, the findings are clinically relevant.

The FoundationOne test may be detecting a broader range of aberrations than the Guardant360, but the researchers think the discordance between the two tests stems from other causes.

The researchers pointed to at least two other studies with similar observations, including one based only on tumor tissue-sampling and another that compared blood and tumor testing.

To improve the clinical usefulness of next-generation sequencing tests for cancer treatment, the researchers point to a need for more in-depth comparisons of test results across larger numbers of patients.
-end-
SouthSound CARE and the Chan Soon-Shiong Family Foundation funded this study. Other institutions participating included Northwest Medical Specialties in Puyallup, Wash., and the Fred Hutchinson Institute for Cancer Outcomes Research.

University of Washington Health Sciences/UW Medicine

Related Cancer Articles:

UCI researchers uncover cancer cell vulnerabilities; may lead to better cancer therapies
A new University of California, Irvine-led study reveals a protein responsible for genetic changes resulting in a variety of cancers, may also be the key to more effective, targeted cancer therapy.
Breast cancer treatment costs highest among young women with metastic cancer
In a fight for their lives, young women, age 18-44, spend double the amount of older women to survive metastatic breast cancer, according to a large statewide study by the University of North Carolina at Chapel Hill.
Cancer mortality continues steady decline, driven by progress against lung cancer
The cancer death rate declined by 29% from 1991 to 2017, including a 2.2% drop from 2016 to 2017, the largest single-year drop in cancer mortality ever reported.
Stress in cervical cancer patients associated with higher risk of cancer-specific mortality
Psychological stress was associated with a higher risk of cancer-specific mortality in women diagnosed with cervical cancer.
Cancer-sniffing dogs 97% accurate in identifying lung cancer, according to study in JAOA
The next step will be to further fractionate the samples based on chemical and physical properties, presenting them back to the dogs until the specific biomarkers for each cancer are identified.
Moffitt Cancer Center researchers identify one way T cell function may fail in cancer
Moffitt Cancer Center researchers have discovered a mechanism by which one type of immune cell, CD8+ T cells, can become dysfunctional, impeding its ability to seek and kill cancer cells.
More cancer survivors, fewer cancer specialists point to challenge in meeting care needs
An aging population, a growing number of cancer survivors, and a projected shortage of cancer care providers will result in a challenge in delivering the care for cancer survivors in the United States if systemic changes are not made.
New cancer vaccine platform a potential tool for efficacious targeted cancer therapy
Researchers at the University of Helsinki have discovered a solution in the form of a cancer vaccine platform for improving the efficacy of oncolytic viruses used in cancer treatment.
American Cancer Society outlines blueprint for cancer control in the 21st century
The American Cancer Society is outlining its vision for cancer control in the decades ahead in a series of articles that forms the basis of a national cancer control plan.
Oncotarget: Cancer pioneer employs physics to approach cancer in last research article
In the cover article of Tuesday's issue of Oncotarget, James Frost, MD, PhD, Kenneth Pienta, MD, and the late Donald Coffey, Ph.D., use a theory of physical and biophysical symmetry to derive a new conceptualization of cancer.
More Cancer News and Cancer Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Warped Reality
False information on the internet makes it harder and harder to know what's true, and the consequences have been devastating. This hour, TED speakers explore ideas around technology and deception. Guests include law professor Danielle Citron, journalist Andrew Marantz, and computer scientist Joy Buolamwini.
Now Playing: Science for the People

#576 Science Communication in Creative Places
When you think of science communication, you might think of TED talks or museum talks or video talks, or... people giving lectures. It's a lot of people talking. But there's more to sci comm than that. This week host Bethany Brookshire talks to three people who have looked at science communication in places you might not expect it. We'll speak with Mauna Dasari, a graduate student at Notre Dame, about making mammals into a March Madness match. We'll talk with Sarah Garner, director of the Pathologists Assistant Program at Tulane University School of Medicine, who takes pathology instruction out of...
Now Playing: Radiolab

How to Win Friends and Influence Baboons
Baboon troops. We all know they're hierarchical. There's the big brutish alpha male who rules with a hairy iron fist, and then there's everybody else. Which is what Meg Crofoot thought too, before she used GPS collars to track the movements of a troop of baboons for a whole month. What she and her team learned from this data gave them a whole new understanding of baboon troop dynamics, and, moment to moment, who really has the power.  This episode was reported and produced by Annie McEwen. Support Radiolab by becoming a member today at Radiolab.org/donate.