Cancer-Sniffing Dogs 97% Accurate in Lung Cancer Detection

Beagles Beat Out Advanced Technology

Three beagles have demonstrated that they can identify lung cancer by scent, a first step in finding specific biomarkers for the disease.

Researchers say the dogs’ abilities could lead to the development of effective, safe, and inexpensive methods for mass cancer screening. The double-blind study appears in the July edition of The Journal of the American Osteopathic Association.

After eight weeks of training, the beagles—who have a superior sense of smell—could distinguish with a 97% accuracy rate between blood serum samples from patients with malignant lung cancer and samples from healthy controls.

The dogs were led into a room with blood serum samples at nose level: some samples were from patients with non–small-cell lung cancer (NSCLC) and others were from healthy controls. If the dogs sat down after thoroughly sniffing a sample, it indicated a positive finding for cancer. If they moved on, it indicated that they had found no cancer.

A second version of the study is nearing completion, in which the dogs are working at identifying lung, breast, and colorectal cancer from samples of patients’ breath collected in a face mask. Findings indicate that the dogs are just as effective at detecting cancer with this method. 

Next, the researchers plan to further divide the samples based on chemical and physical properties, and present them to the dogs until specific biomarkers for each cancer are identified.

The goal is to develop an over-the-counter screening test, similar to a pregnancy test regarding cost, simplicity, and availability. This could involve a device that someone breathes into, where a color change would indicate a positive or negative finding.
Lung cancer is the leading cause of cancer death worldwide in adults; each year, more than 200,000 people in the U.S. receive a diagnosis. The five-year survival rate for stage 1A NSCLC is 92%, and drops to 13% in stage 3C. After metastasis, five-year survival rates range from 10% to less than 1%.

Screening and imaging for lung cancer are expensive and not always reliable. Previous studies indicate that 90% of missed lung cancers occur when using chest X-rays, and CT scans have difficulty identifying small, central, juxtavascular lung cancers.

The scientists believe their research could lead to better screening and diagnosis solutions, and potentially change how cancer is detected. 

At present, they say, it appears that dogs are better at screening for cancer than the most advanced technology.

Source: American Osteopathic Association, June 17, 2019