Dogs can be used by doctors to literally smell lung cancer in the patients’ breath, according to a German study, which comes to confirm assumptions and theories first produced in the late 80’s.
The researchers conducted experiments with four dogs (two German Shepherds, an Australian Shepherd and a Labrador). They found that the dogs were able to make the correct diagnosis in 71% of the cancer patients.
The scientists have not yet understood what chemical substance (or substances) dogs smell in the patients’ breath. This knowledge is essential if an innovative programme of diagnosis is to be promoted, however that is still far from being realized.
The most likely scenario is that electronic “noses”, able to detect the same chemicals as those dogs do, will be created. From 1989 up until today, several studies have provided evidence that dogs can smell different types of cancer including skin, bladder, bowel and breast cancer. It is believe that cancer tumors give off organic chemicals that only dogs are able to detect.
The German researchers used three groups of cancer patient volunteers for their experiments: 110 healthy, 60 with lung cancer and 50 with chronic obstructive pulmonary disease. All were given air tubes in which they exhaled. The tubes were then smelled by the dogs who didn’t seem to be confused at all by the different chemicals found in the breaths of healthy smokers or those that had lung disease but not cancer.
Dogs correctly identified 71 out 100 cancer patient samples and correctly rejected 372 out of 400 samples from non-cancer patients.
Lung cancer is the second most common cancer type among men and women in Europe, with more than 340,000 deaths annually. The principal cause of lung cancer is smoking. Lung cancer is also the most fatal cancer type worldwide. This is because there are no clear symptoms on the outset of the disease, therefore diagnosis is often slow. It is vital for scientists to find new methods to detect lung cancer early.
Unfortunately, dogs cannot communicate the biochemistry of cancer to scientists and make their lives easier.