Dogs ‘sniff’ out early lung cancer accurately

By Dr. Ananya Mandal, MDAug 23 2011

According to a new study in the European Respiratory Journal dogs are better at sniffing out the early markers of lung cancer than the latest medical technologies at our disposal.

Lung cancer is the second most frequent form of cancer in men and women across the United States and Europe, accounting for approximately 500,000 deaths per year. It is notoriously difficult to identify early. In many cases, the patient doesn’t show any symptoms and detection of the disease happens by chance. If someone isn’t that lucky, the cancer is likely to have already progressed by the time it is found.

The researchers at Schillerhoehe Hospital involved four dogs including two German shepherds, one Australian shepherd and one Labrador retriever, that were trained to reliably identify specific volatile organic compounds (VOCs) that are linked to the presence of lung cancer.  The latest medical methods for identifying lung cancer VOCs are generally unreliable because there is a high risk of interference in the results, especially from the residuals of tobacco smoke, and the results can take a long time to process.

Trained dogs were asked to sniff out a study group that included lung cancer patients, chronic obstructive pulmonary disease (COPD) patients, and healthy volunteers.  The dogs successfully identified 71 samples of lung cancer out of a possible 100.  They also correctly detected 372 samples that did not have lung cancer out of a possible 400 –  a 93% success rate.

The dogs were also able to detect the difference between lung cancer and chronic obstructive pulmonary disease, which study author Enole Boedeker said is common in patients with lung cancer. “The dogs could recognize the cancer sample as easily as between the breath samples of the healthy study participants,” Boedeker said, adding that current lab tests for lung cancer are unable to detect the difference. These results are consistent with previous research that showed that dogs can smell out skin, lung, breast, bladder and ovarian cancers.