Home' Trinidad and Tobago Guardian : April 29th 2017 Contents A22 body & soul
guardian.co.tt Saturday, April 29, 2017
Blood test offers hope for
better lung cancer treatment
Researchers have taken an important step to-
ward better lung cancer treatment by using blood
tests to track genetic changes in tumours as they
progress from their very earliest stages.
With experimental tests that detect bits of DNA that
tumours shed into the blood, they were able to detect
some recurrences of cancer up to a year before imaging
scans could, giving a chance to try new therapy sooner.
It's the latest development for tests called liquid bi-
opsies, which analyse cancer using blood rather than
tissue samples. Some doctors use these tests now to
guide care for patients with advanced cancers, mostly
in research settings. The new work is the first time tests
like this have been used to monitor the evolution of lung
tumours at an early stage, when there's a much better
chance of cure.
Only about one third of lung cancer cases in the United
States are found at an early stage, and even fewer in
other parts of the world. But more may be in the future
as a result of screening of longtime smokers at high risk
of the disease that started a few years ago in the US.
Early-stage cases are usually treated with surgery.
Many patients get chemotherapy after that, but it helps
relatively few of them.
"We have to treat 20 patients to cure one. That's a
lot of side effects to cure one patient," said Dr Charles
Swanton of the Francis Crick Institute in London.
The new studies he led suggest that liquid biopsies
might help show who would or would not benefit from
chemotherapy, and give an early warning if it's not work-
ing so something else can be tried.
Cancer Research UK, a charity based in England,
paid for the work, and results were published online
Wednesday by Nature and the New England Journal
To be clear: This kind of care is not available yet --- the
tests used in these studies are experimental and were
customised in a lab to analyse the genes in each patient's
cancer. But the technology is advancing rapidly.
The company that generated the tests for the study in
Nature --- California-based Natera Inc --- plans to offer
the tests for research by universities and drug companies
later this year and hopes to have a version for routine
use in cancer care next year.
"This is coming, and it's coming fast," said Dr David
Gandara, a lung specialist at the University of Califor-
nia, Davis, who had no role in the studies but consults
for two companies developing liquid biopsies. A test
that could spare many people unnecessary treatment
"would be huge," he said.
In the studies, researchers analysed tumours from
about 100 people with non-small cell lung cancer, the
most common form of the disease. Even in these ear-
ly-stage cases, they found big variations in the number
of gene flaws, and were able to trace how the tumours'
genes changed over time.
People with many gene or chromosome problems were
four to five times more likely to have their cancer return,
or to die from their disease within roughly two years.
They also looked at 14 patients whose cancers recurred
after surgery, and compared them to 10 others whose
did not. Blood tests after surgery accurately identified
more than 90 per cent of them that were destined to
relapse, up to a year before imaging tests showed that
The results suggest that using liquid biopsy tests to
help select and adjust treatments is "now feasible," at
least from a scientific standpoint, the authors write.
A big issue is cost, though. Liquid biopsies sold now in
the US cost nearly US$6,000. Tests that more narrowly
track a patient's particular tumor gene changes, like
the one in these studies, may cost less. They may save
money in the long run, by preventing futile treatment,
but this has yet to be shown.
Liquid biopsy video: https://www.youtube.com/
Lung cancer treatment info: https://www.cancer.org/can-
In the studies, researchers analysed tumours
from about 100 people with non-small cell lung
cancer, the most common form of the disease.
Even in these early-stage cases, they found
big variations in the number of gene flaws,
and were able to trace how the tumours' genes
changed over time. People with many gene or
chromosome problems were four to five times
more likely to have their cancer return, or to die
from their disease within roughly two years.
Dr Claudia Henschke, chief of the Division of Chest Imaging, right, and CT
supervisor Gus Daphnis watch the lung scan of a patient at New York Hospital -
Cornell Medical Center in New York. The test, called a spiral or helical CT scan,
detects lung abnormalities as small as five millimetres, less than a fifth of an
inch. PHOTO: RICHARD DREW
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