Fact or Myth: Can Dogs Detect Cancer?

This is a FACT.

Perhaps you’ve heard the news reports about dogs that have sniffed out their owners’ skin, breast, or lung cancers by persistently pawing or nosing the affected area. These cases aren’t sensationalized media, as evidenced by numerous studies that show that dogs detect cancer.

secrets to longevityA Cheap, Non-Invasive Way to Detect Thyroid Cancer

The latest study involves a German shepherd mix named Frankie, who detected thyroid cancer with 90% accuracy. Researchers from University of Arkansas Medical Sciences trained Frankie to lie down when he sniffed evidence of thyroid cancer in urine samples and to turn away when he did not. They then collected urine samples from 34 patients, and screened them with biopsies and diagnostic surgeries to determine that 15 had thyroid cancer and 19 had benign thyroid disease. The results were hidden from researchers and the dog handler. Frankie correctly diagnosed 30 out of the 34 patients simply by sniffing their urine samples, and had only 2 false negatives and 2 false positives, an accuracy comparable to that of current thyroid cancer screenings.

Doctors use fine-needle aspiration biopsy to diagnose thyroid cancer. It involves inserting a needle through the neck and into the thyroid gland to remove thyroid tissue for screening. It’s invasive and costly, which makes these latest findings even more exciting.

Is Frankie an Anomaly?

Frankie is definitely impressive, but he’s certainly not the only cancer-detecting pooch out there. A 2011 study published in the European Respiratory Journal demonstrated that trained dogs could successfully sniff out lung cancer just by sniffing patients’ breath! Dogs could even detect cancer in smokers or patients afflicted with chronic obstructive pulmonary disease…not even current cancer screening tests can do that! The dogs (two German Shepherds and a lab) correctly identified lung cancer in 71 out of 100 patients and correctly identified 372 out of 400 cancer-free patients—that’s an extremely low 7% of false positives.

Japanese researchers found that dogs could detect colon cancer in human breath and stool samples with nearly 90% accuracy, a slightly lower success rate than colonoscopies.

Sniffing Out Cancer

A dog has more than 500 million scent receptors on its nose (a human has around 5 million). Researchers theorize that dogs are able to sniff out subtle changes in volatile organic compounds (VOCs). For perspective, 4000 VOCs have been identified in human breath. Essentially, dogs can smell trouble, and disease, a mile away.

What’s the next step? Researchers hope to determine the exact way dogs sniff out cancer in order to build non-invasive and cost-effective technology that mimics the process. In the meantime, pay attention to the signs your dog gives you. These canines are more perceptive than humans think!