The Irish Times – Tuesday, February 1, 2011

DICK AHLSTROM, Science Editor

A DOG has been trained to detect colorectal cancer in patients. The Labrador Retriever is as accurate as the current best diagnostic methods and is even able to sniff out very early stage bowel cancer before clinical symptoms appear.

Researchers based in Japan trained the dog to identify patients with the disease using scent.

The dog achieved a 95 per cent accuracy when testing exhaled breaths from the subject and 98 per cent accuracy when testing a stool sample.

The eight-year-old female black Labrador was trained at the St Sugar Cancer Sniffing Dog Training Centre in Chiba, Japan.

Initially it was trained for water rescue but moved across to cancer detection dog training when a three-year-old.

Previous studies have indicated dogs can be excellent diagnosticians with early research and anecdotal evidence suggesting they can sniff out bladder, skin, lung, prostate, breast and ovarian cancers, the authors write in the journal, Gut.

“this study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating through the body. these odour materials may become effective tools in [colon cancer] screening.”

The use of scents to detect cancer was at a very early stage with just a small number of preliminary studies completed to date, said the Irish Cancer Society in a comment on the research.

“this area of research would require considerably more investigation in order to demonstrate potential in the detection of cancer,” a spokeswoman said.

In the Japanese study, the dog was trained to identify the scent associated with colon cancer and then underwent a series to tests to see whether she could identify the scent in test samples.

Five samples of either breath or stool were presented to the dog, only one of which was cancerous. she was able to choose correctly in 33 out of 36 breath tests and 37 out of 38 stool tests.

Importantly, her highest detection rates were among those samples taken from people with early stage disease, according to the authors.

This means it may be possible to develop tests to pick up the disease early, before it has had a chance to spread.

However, the researchers believe it is too impractical and expensive to use dogs to screen cancer patients.

The research does show there is a compound present that gives an early warning of colon cancer and if isolated, it could be used in a new kind of test.

If you are concerned about or affected by cancer, please call the National Cancer Helpline on Freefone 1800 200 700.