New Cancer Detection Tool?

February 7, 2011
Lisa Schulmeister

Report of dog trained to detect the scent of cancer is intriguing.

The lab assistant was a 9-year old Labrador retriever named Marine. The study, conducted in Japan, used Marine to smell breath samples from people with lung and breast cancer, and tissue samples from women with ovarian cancer. Previous studies had already reported that trained dogs can detect, through smell, melanoma, bladder, lung, breast, and ovarian cancer.

For the Japanese study, which took place between November 2008 and June 2009, the researchers obtained exhaled breath and watery stool samples from people with colorectal cancer and healthy controls before they underwent a diagnostic test with a colonoscopy. There were 33 groups of breath samples and 37 groups of stool samples, each group comprising one sample from a person with colorectal cancer, and four control samples from people who did not have cancer. The samples were randomly separated and put into five boxes. Marine and her handler were then given the task of picking out a box. Marine first smelled a standard breath sample from a different patient who definitely had colorectal cancer (not included in the test samples), and then sniffed each of the test boxes, and sat down in front of the box that smelled like the standard sample. Marine was able to detect cancer with a much higher level of accuracy than chance alone. The findings were reported “online first” on January 31, 2011 in the journal Gut.

The researchers hope that Marine’s detection abilities will lead to new ways of cancer screening, based on the idea that cancer tumors secrete specific volatile compounds. Once those compounds can be reliably identified, then it’s just a matter of time before a detection device or method could be developed. It’s an intriguing idea.