Scimex: Israeli and Latvian scientists have developed a new type of technology
that can sense small chemical changes in exhaled breath in order to
accurately identify the development of stomach cancer. The authors
found both patients with cancer and those without the disease had
distinctive 'breath prints', and the test was also able to accurately
distinguish between the different pre-cancerous stages, marking out
those patients at low and high risk of developing gastric cancer. A new type of technology that senses minute changes in the levels of
particular compounds in exhaled breath, accurately identifies high risk
changes which herald the development of stomach cancer, reveals research
published online in the journal Gut.
The findings prompt the researchers to suggest that the technology—known
as nanoarray analysis—could be used not only to test for the presence
of stomach cancer, but also to monitor those at high risk of
subsequently developing the disease.
Gastric cancer develops in a series of well-defined steps, but there's
currently no effective, reliable, and non-invasive screening test for
picking up these changes early on. Most people in the developed world
are diagnosed when it's too late to save their lives.
Previous research has concluded that nanoarray analysis could be used to
detect stomach cancer, but these studies have involved small numbers of
people, and none has looked at the technology's ability to pick up
pre-cancerous changes.
The researchers therefore collected two breath samples from 484 people,
after a 12 hour fast and abstention from smoking for at least three
hours.
Ninety nine of the participants had already been diagnosed with stomach
cancer, but not yet treated with chemotherapy or radiotherapy.
Participants were asked about their smoking and drinking habits and
tested for Helicobacter pylori infection, a known risk factor for
stomach cancer.
The first breath sample was analysed using a technique (GCMS) that
measures the various volatile organic compounds in exhaled breath. The
second sample was subjected to nanoarray analysis combined with pattern
recognition.
The GCMS results showed that both patients with cancer and those without the disease had distinctive 'breath prints.'
Out of a total of 130 volatile organic compounds identified by GCMS in
exhaled breath, levels of eight differed significantly when samples from
the gastric cancer group were compared with those from the groups with
pre-cancerous changes.
Furthermore, the nanoarray sensing patterns were able to accurately
distinguish between the different pre-cancerous stages, marking out
those patients at low and high risk of developing gastric cancer.
The findings held true, irrespective of other influential factors, such
as age, alcohol intake, and use of stomach acid suppressant drugs
(proton pump inhibitors).
The researchers point out that GCMS technology cannot be used for
screening purposes, because it is very expensive and requires lengthy
processing times and considerable expertise to operate it.
Nanoarray analysis, on the other hand, is not only accurate and highly
sensitive, but offers a much simpler and cheaper alternative, they say.
Being able to accurately differentiate between low and high risk changes
would avoid unnecessary endoscopies, and would enable any progression
to cancer or signs of disease recurrence to be monitored, they suggest.
A large trial involving thousands of patients, including those with
stomach cancer or pre-cancerous changes, is currently under way in
Europe to test the technology's suitability as a screening method, they
add.
"The attraction of this test lies in its non-invasiveness, ease of use
(therefore high compliance would be expected), rapid predictiveness,
insensitivity to confounding factors, and potentially low cost," they
conclude.