[thedoc (OP)]

Destiny asked the Naked Scientists:
   How do dogs sniff out cancer?
What do you think?

[puppypower]

A dog's sense of smell is a highly tuned analytical tool. Dogs are able to infer from low level data, especially if they are treated and trained so they have incentive to analyze certain data. For example, a good tracking dog can smell and detect single skin cells. Our skin constantly defoliates dead skin cells, as a person walks and moves. These are on our clothes and we leave a trail of skin cells with our unique scene as we walk. Skill track dogs can follow this trail.

Cancer cells have their own scent. These do not fall off like skin cells, but a collection of these, can result in certain odors being present on the body that a dog can be trained to notice. Skin cancer would be easy for a dog to detect, since these are on the surface. The body fights cancer with the waste ending up in the digestive track for recycle. This makes your solid and liquid waste, have a certain smell dogs could be trained to detect. Dogs like sniffing butts anyway, to determine eating history and other parameters. We could train the dog to notice other parameters such as scent marker drugs that trigger if cancer is present.

[Colin2B]

Destiny asked the Naked Scientists:
   How do dogs sniff out cancer?
What do you think?

I think that given this report "The woman who can smell Parkinson's disease"
http://www.bbc.co.uk/news/uk-scotland-34583642
I would think it highly likely dogs could be trained to detect certain illnesses.

[Candy Swift]

"Dogs can help doctors “smell” cancer? It may sound incredible, but in fact, this research has made great progress. Recently, the “Cancer Sniffing Dogs Project”, approved by the British NHS, has entered the testing phase. Milton Keynes University Hospital of Buckinghamshire also approved this research program proposed by a charity organization. This is what I read in the article Can Dogs Smell Cancer by Creative Biolabs.

[Lor]

A wife of a man with Parkinsons disease noticed that his odor changed when he came down with it. Scientists tested her ability and conformed the skill she picked up. In a blind quiz she picked out 11 of the 12 people who had parkinsons disease by smelling shirts they had previously worn . Even more, the 12th person she guessed wrongly on was diagnosed a few months later.

[chris]

Scientists at Cambridge University have been developing a breath test for Parkinson's, which works in basically the same way

[Harri]

So is the lady smelling a kind of waste product? Is sweat a way for the body to get rid of toxins and wastes from the whole body including the brain?

On a couple of occasions when I've been in the company of an old person who didn't have long left to live I thought I could smell a distinctive odor! I don't mean the 'old person smell.' It's very distinctive and even now I can smell the odor in my head! Am I actually smelling the breakdown of bodily tissue? or what? Is this possible?

[Colin2B]

So is the lady smelling a kind of waste product? Is sweat a way for the body to get rid of toxins and wastes from the whole body including the brain?

This article about the Milton Keynes trial on prostrate cancer suggests that cancer cells could produce volatile (smelly) compounds in urine
. http://uk.reuters.com/article/2015/08/26/us-cancer-dogs-idUKKCN0QV1RR20150826
The current test for prostrate cancer PSA looks for a protein which may well have a smell passed to urine.
Diabetics can produce ketones which makes the breath smell of rotten apples.
I suspect there are many processes in the body during illness that will produce a scent a dog would detect as being unusual. Whether the scent is in sweat, breath, urine would depend on the chemicals and how they are released.

[RD]

The woman who can smell Parkinson's disease

http://www.bbc.co.uk/news/uk-scotland-34583642

So is the lady smelling a kind of waste product? Is sweat a way for the body to get rid of toxins and wastes from the whole body including the brain? ...

A possible explanation how Parkinson's can change body odour ? ...

Parkinson's disease reduces dopamine levels.
Reduced dopamine levels can cause hyperprolactinaemia.
Hyperprolactinaemia reduces the level of sex-hormones.
Reduction in level of sex-hormones changes the person's body-odour.

[ritchie]

A dog can detect scent traces of 2 parts per million in normally circulating air, so it's highly likely imo.