Colorectal cancer screening with odour material by canine scent detection

Abstract

ObjectiveEarly detection and early treatment are of vital importance to the successful treatment of various cancers. The development of a novel screening method that is as economical and non-invasive as the faecal occult blood test (FOBT) for early detection of colorectal cancer (CRC) is needed. A study was undertaken using canine scent detection to determine whether odour material can become an effective tool in CRC screening.DesignExhaled breath and watery stool samples were obtained from patients with CRC and from healthy controls prior to colonoscopy. Each test group consisted of one sample from a patient with CRC and four control samples from volunteers without cancer. These five samples were randomly and separately placed into five boxes. A Labrador retriever specially trained in scent detection of cancer and a handler cooperated in the tests. The dog first smelled a standard breath sample from a patient with CRC, then smelled each sample station and sat down in front of the station in which a cancer scent was detected.Results33 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.ConclusionsThis study shows that a specific cancer scent does indeed exist and that cancer-specific chemical compounds may be circulating throughout the body. These odour materials may become effective tools in CRC screening. In the future, studies designed to identify cancer-specific volatile organic compounds will be important for the development of new methods for early detection of CRC.

Targeted Proteomics for Multiplexed Verification of Markers of Colorectal Tumorigenesis

“…Electronic-nose technology and canine and Caenorhabditis elegans scent detection have been used to analyze the presence of these compounds in breath, urine, and stool samples (89 -91) from CRC patients. The reported sensitivity and specificity of these approaches in distinguishing between individ-uals with and without CRC or advanced adenomas are comparable to those of conventional colonoscopy (Ͼ90%) (90,91). In the present study, we found significantly increased levels of metabolic enzymes in the adenomas (SORD, LDHA) and adenocarcinomas (SORD, G6PD, LDHA) we examined.…”

Fragrant environment with α-pinene decreases tumor growth in mice

“…Many diseases are considered to be characterized by specific odors, particularly cancer, a characteristic known as byoshu in Japan (9). Recently it was reported that odors from patients with colorectal cancer could be identified by dogs (19). Byoshu from cancer patients can become so strong that it adversely effects not only the patient himself, but also his family and medical staff.…”

Cancer diagnosis: from dogs to DNA or from DNA to dogs?

“…Additional studies are needed to clarify positive fi ndings from the screening test, colonoscopy or barium enema, imposing a certain burden both on the patients and the system. The results of the study by Sonoda et al (11) show that the sensitivity of canine olfactory detection when compared with colonoscopy fi ndings was over 90 % , while the specifi city for stool and breath samples was 99 % . These results may look almost too good to be true.…”

“…The potential of canine olfactory detection in cancer diagnosis could be illustrated by a recent Japanese study in patients with colorectal cancer (11) . Colorectal cancer is one of the leading causes of cancer-related death.…”