Dogs Can Smell Lung Cancer

Photo: itsbeach

A new study by German researchers apparently shows that “sniffer dogs” can reliably smell lung cancer on the breath of patients. The finding could significantly improve early detection methods of the disease, which is the deadliest form of cancer worldwide. The research was published in European Respiratory Journal. Here’s the abstract:

Patient prognosis in lung cancer (LC) largely depends on early diagnosis. Exhaled breath of patients may represent the ideal specimen for future LC screening. However, the clinical applicability of current diagnostic sensor technologies based on signal pattern analysis remains incalculable due to their inability to identify a clear target. To test the robustness of the presence of a so far unknown volatile organic compound in the breath of patients with LC, sniffer dogs were applied.

Exhalation samples of 220 volunteers (healthy individuals, confirmed LC, or COPD) were presented to sniffer dogs following a rigid scientific protocol. Patient history, drug administration and clinicopathological data were analyzed to identify potential bias or confounders.

LC was identified with an overall sensitivity of 71% and a specificity of 93%. LC detection was independent from COPD and the presence of tobacco smoke and food odors. Logistic regression identified two drugs as potential confounders.

It must be assumed, that a robust and specific volatile organic compound (or pattern) is present in the breath of patients with LC. Additional research efforts are required to overcome the current technical limitations of electronic sensor technologies to engineer a clinically applicable screening tool.

From an article in ScienceDaily:

Author of the study, Thorsten Walles from Schillerhoehe Hospital, said: “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!”


Re: "Additional research efforts are required to overcome the current technical limitations of electronic sensor technologies to engineer a clinically applicable screening tool."

Why does it have to be an electronic sensor? Why not just use the dogs?


Got to love service dogs!


this is not new - well, perhaps the dogs are (but using dogs to sniff out other types of cancer is also not new). The earliest paper I have in my current docs pile related to this is Gordon, Clin. Chem. 31, 8, *1985* entitled: "Volatile Organic Compounds in Exhaled Air from Patients with Lung Cancer". Anyway - people have been working on this issue for at least 25 years, and while VOC signatures remain a hot topic in the disease diagnostic field, this particular paper doesn't seem from the abstract to show anything new.

(Oh - the abstract of the 1985 paper: "Using a specially developed breath collection technique and
computer-assisted gas chromatography/mass spectrometry
(GC/MS), we have identified in the exhaled air of lung cancer
patients several volatile organic compounds that appear to
be associated with the disease. The GC-MS profiles of 12
samples from lung cancer patients and 17 control samples
were analyzed by using general computerized statistical
procedures to distinguish lung cancer patients from controls.
The selected volatile compounds had sufficient diagnostic
power in the GC/MS profiles to allow almost complete
differentiation between the two groups in a limited patient
population." )



Will this be included under Lab work?
What's next? Cat scans?


Does the somewhat low sensitivity indicate that there may be different types of lung cancer and the VOC isn't present in some? what is the sensitivity and specificity for e.g. cocaine dogs detecting trace amounts of cocaine? That would be interesting to compare this to.