Many lung cancer patients die because their cancer isn’t detected early enough. Early detection of cancer can be key to patient survival. Everyone has heard of guide dogs for the blind or hearing dogs for the deaf, but soon dogs may be used to detect cancer.
There is an unknown compound on the breath of people with lung cancer so doctors from Germany thought they would see whether dogs would be able to detect the cancer.
They worked with 220 volunteers including lung cancer patients, chronic obstructive pulmonary disease (COPD) patients and healthy volunteers. They used dogs that had been specifically trained.
The dogs were able to correctly identify lung cancer in 71 of 100 cancer patients. They also correctly identified that 372 samples out of 400 did not show cancer.
The dogs could also differentiate between lung cancer, COPD and tobacco smoke even in the presence of food odor and drugs.
The study authors wrote, “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.
"LC was identified with an overall sensitivity of 71 percent and a specificity of 93 percent. LC detection was independent from COPD and the presence of tobacco smoke and food odors ..."
The lead researcher, 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!"
Dogs are renowned for their ability to detect illnesses and save human lives. A dog saved his owner, Jerry Douthett, after he bit off his infected toe.