Canine cancer detection is an approach to

cancer screening Cancer screening aims to detect cancer before symptoms appear. This may involve blood tests, urine tests, DNA tests, other tests, or medical imaging. The benefits of screening in terms of cancer prevention, early detection and subsequent treatme ...

that relies upon the claimed

olfactory The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it ...

ability of

dog The dog (''Canis familiaris'' or ''Canis lupus familiaris'') is a domesticated descendant of the wolf. Also called the domestic dog, it is derived from the extinct Pleistocene wolf, and the modern wolf is the dog's nearest living relative. Do ...

s to detect, in urine or in breath, very low concentrations of the

alkane In organic chemistry, an alkane, or paraffin (a historical trivial name that also has other meanings), is an acyclic saturated hydrocarbon. In other words, an alkane consists of hydrogen and carbon atoms arranged in a tree structure in which ...

s and

aromatic compounds Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one or more aromatic rings. The parent member of aromatic compounds is benzene. The word "aromatic" originates from the past groupin ...

generated by malignant

tumors A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...

. While some research has been promising, no verified studies by secondary research groups have substantiated the validity of positive, conclusive results.

Background

Media coverage

The proposal that dogs can detect cancer attracted widespread coverage in the general media. In 2015 the

Huffington Post ''HuffPost'' (formerly ''The Huffington Post'' until 2017 and sometimes abbreviated ''HuffPo'') is an American progressive news website, with localized and international editions. The site offers news, satire, blogs, and original content, and ...

reported that studies have suggested that dogs may be able to detect

lung cancer Lung cancer, also known as lung carcinoma (since about 98–99% of all lung cancers are carcinomas), is a malignant lung tumor characterized by uncontrolled cell growth in tissue (biology), tissues of the lung. Lung carcinomas derive from tran ...

melanoma Melanoma, also redundantly known as malignant melanoma, is a type of skin cancer that develops from the pigment-producing cells known as melanocytes. Melanomas typically occur in the skin, but may rarely occur in the mouth, intestines, or eye ( ...

breast cancer Breast cancer is cancer that develops from breast tissue. Signs of breast cancer may include a lump in the breast, a change in breast shape, dimpling of the skin, milk rejection, fluid coming from the nipple, a newly inverted nipple, or a re ...

and

bladder cancer Bladder cancer is any of several types of cancer arising from the tissues of the urinary bladder. Symptoms include blood in the urine, pain with urination, and low back pain. It is caused when epithelial cells that line the bladder become mali ...

, and that dogs can be trained to detect cancer in 93% of cases. In 2016, actress

Shannen Doherty Shannen Doherty (, born April 12, 1971) is an American actress. She is known for her roles as Jenny Wilder in ''Little House on the Prairie'' (1982–1983); Maggie Malene in ''Girls Just Want to Have Fun'' (1985); Kris Witherspoon in '' Our Hous ...

told ''Entertainment Tonight'' in an interview that her dog identified her breast cancer before doctors could diagnose it. ''National Geographic'' said that "man's best friend can detect various cancers, including prostate cancer, colorectal cancer and melanoma." On the other hand, a review by ''Australian Popular Science'' found that the more rigorous trials produced less positive results. Another trial reported in ''Nature World News'' found disappointing results, but nevertheless "the researchers... believe that one day, dogs can still detect lung cancer."

NBC The National Broadcasting Company (NBC) is an Television in the United States, American English-language Commercial broadcasting, commercial television network, broadcast television and radio network. The flagship property of the NBC Enterta ...

reported that Britain's

National Health Service The National Health Service (NHS) is the umbrella term for the publicly funded healthcare systems of the United Kingdom (UK). Since 1948, they have been funded out of general taxation. There are three systems which are referred to using the " ...

is behind the first clinical trial to test the ability of canines to detect cancer.

Research

Although the first suggestion of this approach in a medical journal, ''

The Lancet ''The Lancet'' is a weekly peer-reviewed general medical journal and one of the oldest of its kind. It is also the world's highest-impact academic journal. It was founded in England in 1823. The journal publishes original research articles, ...

'', dates back to 1989, there were only occasional publications on the subject in the next decade. However, two studies (one published in 2004 and one in 2006), involving detection in urine, had promising results, with the 2006 report claiming a 99% accuracy in detecting

, although both studies were preliminary and involved small numbers of patients. In a 2011 study,

was identified with a sensitivity of 71% and a specificity of 93%, using breath samples.

Skeptical analysis

In a May 25, 2012 article, “What to make of Medical Dogs” published by

Science-Based Medicine ''Science-Based Medicine'' is a website and blog with articles covering issues in science and medicine, especially medical scams and practices. Founded in 2008, it is owned and operated by the New England Skeptical Society and run by Steven N ...

, Peter Lipson reported on his review of the

scientific literature : ''For a broader class of literature, see Academic publishing.'' Scientific literature comprises scholarly publications that report original empirical and theoretical work in the natural and social sciences. Within an academic field, scient ...

regarding these claims and found valid support for positive conclusions to be lacking:

References

{{reflist Olfaction Working dogs Oncology Cancer screening Alternative medical diagnostic methods

Background

Media coverage

Research

Skeptical analysis

See also

References