Veracyte lung cancer test
could help avoid some risky biopsies
Send a link to a friend
[May 18, 2015] By
Bill Berkrot
(Reuters) - A new diagnostic test from
Veracyte Inc could help many people avoid risky and costly invasive lung
biopsies at a time when millions of American smokers are eligible for
lung cancer screening, according to data from studies presented on
Sunday.
|
The company's Percepta Bronchial Genomic Classifier takes cell
samples from the windpipe of smokers during a bronchoscopy procedure
and analyzes 23 genes for their reaction to exposure to cigarette
toxins.
"These cells are like a canary in a coal mine. They're telling us
whether that nodule deep down in the lung is likely to be a cancer,"
said Dr. Avrum Spira of Boston University School of Medicine,
co-inventor of the test and lead investigator of the studies.
When CT scans turn up a lung abnormality, a patient often undergoes
a bronchoscopy in which a tiny camera inserted down the windpipe
attempts to view the area of concern. About 40 percent of the time
it fails to lead to a diagnosis, often because the scope can't reach
the suspicious site.
"The only way we can be definitive is to stick a needle through the
chest wall or cut open your chest," explained Spira. "We don't want
to miss a cancer, so we end up operating on and biopsying a lot of
people who don't have cancer."
Following CT scan and bronchoscopy, patients are assessed as being
at high, intermediate or low risk for cancer. The sweet-spot for the
Veracyte test, Spira said, was the intermediate-risk group, as the
diagnostic was able to re-classify many of them as low risk with a
91 percent degree of accuracy.
That meant they could be monitored via future CT scans rather than
undergo biopsies.
"We now have a new tool to help us evaluate smokers who are at risk
for having lung cancer and identify those who don't need to undergo
invasive procedures," said Spira, who presented the studies at the
American Thoracic Society meeting in Denver.
A needle biopsy has a 15 to 25 percent risk of causing a collapsed
lung and surgical biopsy costs more than $20,000.
Veracyte, which also sells a thyroid cancer test, said its lung test
would cost between $3,000 and $4,000.
[to top of second column] |
This year, more than eight million Americans with a history of heavy
smoking became eligible for annual low-dose CT screening through new
health coverage requirements. That is likely to lead to far higher
numbers of biopsies.
The Genomic Classifier was tested in two large studies involving 639
patients. The second 341-patient study served to confirm results
from the prior trial.
While researchers reported a high number of false positives with
Verasyte's test that would add expense without sparing an
unnecessary biopsy, it proved to be more than 90 percent accurate
when negative for cancer.
The results were also published in the New England Journal of
Medicine. Authors of the Journal article agreed that
intermediate-risk patients were most likely to benefit and concluded
"the gene-expression classifier provided an improvement over
bronchoscopy alone for the detection of lung cancer."
(Reporting by Bill Berkrot; Editing by Andrew Hay)
[© 2015 Thomson Reuters. All rights
reserved.] Copyright 2015 Reuters. All rights reserved. This material may not be published,
broadcast, rewritten or redistributed.
|