Scientists
in Germany have found that sniffer dogs are very reliable when it comes to
detecting lung cancer.
The
researchers used
trained sniffer dogs
- two German shepherds, an Australian shepherd and a Labrador, to detect lung
cancer by using their sharp sense of smell. It has been understood that tumors
produce
volatile organic chemicals
(VOCs), which a dog can smell out.
The
220 patients to be tested fell into
three groups: a) 110 healthy people b) 60 with lung cancer and c) 50 with
chronic obstructive pulmonary disease, which is a lung disease, caused by the
narrowing of the lung airways.
The
subjects breathed into a fleece-filled tube, which absorbed all sorts of
smells. The dogs were made to breathe into the tubes; they sat down in front of
those tubes in which they could "smell" cancer.
It
is to the dogs' credit that the success rate of this screening was 71% and that
they
did not get confused with
chemicals linked to chronic obstructive pulmonary disease or smoking.
Dr Thorsten Walles, from Schillerhoehe Hospital, who is
the chief investigator says: "In the breath of patients with lung cancer,
there are likely to be different chemicals to normal breath samples and the
dogs' keen sense of smell can detect this difference at an early stage of the
disease. Our results confirm the presence of a
stable marker for lung cancer". "This is a big step forward in the
diagnosis of lung cancer, but we still need to precisely identify the compounds
observed in the exhaled breath of patients. It is unfortunate that dogs cannot
communicate the biochemistry of the scent of cancer!"he exclaims.
As
it is not possible for dogs to be present in clinical settings, researchers are
working on "
electronic noses"
which would substitute the dogs.
Science information officer at Cancer Research UK, Dr Laura
McCallum, said: "Although there are now some intriguing studies suggesting
that dogs may be able to smell cancer in some situations, we're still a
long way from understanding exactly
which 'smelly molecules' they are detecting and if these studies are accurate".
"Because
it would be extremely difficult to use dogs in the clinic, further research is
being carried out to learn more about these molecules that are released from
tumors and whether devices such as 'electronic noses' could help sniff them
out," Laura remarked.
The study has been published in the
European
Respiratory Journal.
Reference
1. BBC NEWS
2. Science news
Source: Medindia
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