Sniffer dog (illustrative) 311.
(photo credit: REUTERS/ Wadih Shlink)
LONDON - German scientists experimenting with c have found they can accurately detect lung cancer by smelling breath samples.
In a study carried out by researchers from Schillerhoehe Hospital in Germany, the dogs were able to correctly detect lung tumors in 71 percent of patients, suggesting a similar technique could be used for early detection in future.
"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," said Thorsten Walles, who led the study and published its findings in the European Respiratory Journal on Thursday.
Lung cancer, mostly linked to smoking, is the second most common form of cancer in men and women across Europe and causes more than 340,000 deaths per year. It is also the most common cause of death from cancer worldwide.
The disease is notoriously hard to detect in its early stages and
scientists have been working on using breath tests for possible future
screening programs. The sniffing method relies on identifying so-called
volatile organic compounds (VOCs) that are linked to the presence of
The researchers explained that although many different
possible breath test techniques have been tried, they are very difficult
develop for use in practice in clinics because patients are not allowed
to smoke or eat before the test, sample analysis can take a long time
and there is also a high risk of interference. Because of these reasons,
no lung cancer-specific VOCs have yet been identified.
study the researchers worked specially-trained dogs and with 220
volunteers, including some lung cancer patients, some patients with
chronic obstructive pulmonary disease (COPD) patients and some with no
lung health problems.
The results show the dogs successfully
identified 71 samples with lung cancer out of a possible 100, and
correctly detected 372 samples that did not have lung cancer out of a
The animals were also able to detect lung cancer independently from COPD and tobacco smoke.
said their results confirm that there is a reliable and stable "marker"
for lung cancer in the breath, but there is still a lot of work to do
to find out exactly what that is.
"This is a big step
forward...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."