Thursday, February 10, 2011

The Nose Knows


But I didn’t – know how successfully dogs were being trained to sniff out cancer!

As reported last month in the online version of GUT, an International Journal of Gastroenterology and Hepatology: 
Results 33 and 37 groups of breath and watery stool samples, respectively, were tested. Among patients with CRC and controls, the sensitivity of canine scent detection of breath samples compared with conventional diagnosis by colonoscopy was 0.91 and the specificity was 0.99. The sensitivity of canine scent detection of stool samples was 0.97 and the specificity was 0.99. The accuracy of canine scent detection was high even for early cancer. Canine scent detection was not confounded by current smoking, benign colorectal disease or inflammatory disease. 
This is amazing!

In no way am I suggesting that cancer sniffing dogs replace advanced medical technologies – what I’m excited about is the potential to develop less invasive and less costly tests based on what appears to be a signature smell of cancer-specific chemical compounds. That through non-invasive, inexpensive experimentation (here I’m assuming that costs to train and keep a dog is far less than the time and materials needed to otherwise ensure a promising path for research), this link was found.  Using dogs!

The report says that “Canine olfactory detection of cancer has been reported for melanoma as well as bladder, lung, breast and ovarian cancer.”  I know that cancer sniffing dogs is not a brand new idea, but as reported in the WSJ Health Blog, one of the GUT study’s authors, Hideto Sonoda, told us more about Marine, the black lab with incredible accuracy:
Marine started training as a cancer-detection dog in 2005 and before this study started was already able to pick up the scent of 12 types of cancer in patient breath samples, he writes.
Other dogs have at least 80% accuracy, but Marine was the most accurate — 98% for the stool test and 95% for separate breath samples from the same patients and controls. 
Other animals with a well-developed sense of smell, such as mice, may also be able to detect the cancer scent, writes Sonoda. “However, no other animals can communicate better with people than dogs can,” he writes.
While his comment about communication implies that he is interested in using the dogs themselves for the test work, these results can't be viewed as anything but good news regarding the ease and widespread availability of early cancer detection.


On a related matter, I found the WSJ blog post quite humorous in that it featured a picture of a Pug. The sensitivity of a Pug’s nose was hardly under consideration in its development.  In fact, the extensive specialized epithelial tissue located in the dog’s snout that contribute to its amazing smell detection (up to 100 million times!? more sensitive than a human’s), was cut short in order to breed a dog with such a human-like face.  An ugly human, but a human-like face nonetheless.

In other words, even if dog training for this important work were readily available in an at-home kit, I wouldn’t be able to substitute my sterile squishing at the hospital for some spit sniffing at home anytime soon.

NPR got it right. They showed a Border Collie, widely thought to be the smartest of all the breeds. It's worth mentioning that smart for a dog generally means highly trainable.


Only four more days until the Big Show! (Five for Live! with me and mine.)

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