Cancer Sniffer

A specially trained black labrador retriever, Marine, has been trained to sniff out cancer with stunning accuracy.

The nine-year-old female successfully identified people with bowel cancer more than nine times out of 10 after being given samples of their breath or feces to sniff. The discovery suggests that chemical compounds associated with specific cancers circulate in the body, opening up the prospect of developing tests for a range of cancers that could be applied even in the early stages of the disease.

Marine was trained at the St Sugar Cancer Sniffing Dog Training Centre in Chiba, Japan. She began in 2003 as a water-rescue dog – trained to save people from drowning by dragging them to the shore – but in 2005 was switched to cancer detection. Over four years she learnt to distinguish the smell of a dozen different cancers including breast, stomach, prostate, bladder and skin cancer.

In a study published this year in the medical journal Gut, Marine completed 74 tests in which she was given five breath or stool samples from patients to smell. In each test, only one of the five samples placed in front of her was cancerous. When she smelled a cancer sample, she would sit, alerting her handler.

According to the study, when Marine was smelling breath samples, she was 95 percent as accurate as a colonoscopy in detecting cancer. With stool samples she correctly identified 98 percent of samples with cancer.

If the odor is identified, they say that it could lead to the development of new methods for early detection of colorectal cancer, the most common form.