Colon Cancer Breathalyzer?

Chemical patterns in patients' breath could help physicians detect colon cancer, according to a report in the Dec. 5 online issue of the British Journal of Surgery.

While no one has gone so far as to predict that this will this be the breath (er, death) of colonoscopy, the study's implications that a breath test for colon cancer might be possible are interesting nonetheless.

Researchers correctly identified colon cancer patients 76% of the time by using gas chromatography and mass spectrometry to analyze volatile organic compounds linked to tumor growth collected in the exhaled breath of 37 cancer patients and 41 healthy individuals. Tumor growth involves several metabolic changes leading to the production of specific compounds or cancer "fingerprints" in the breath, notes the study.

The researchers say breath analysis appears to have potential clinical application in colorectal cancer screening, but concede further studies are needed to confirm the test's accuracy in clinical settings.

Durado Brooks, MD, MPH, director of prostate and colorectal cancers for the American Cancer Society, agrees that the real-world application of the study's findings are inconclusive, especially because effective colon cancer screenings — annual stool tests, sigmoidoscopy every 5 years, along with stool testing every 3 years, or colonoscopy every 10 years — already exist.

He also points out the study's breath test was inaccurate one-fourth of the time, and can't detect colon polyps that can be removed before they develop into cancerous growths. "We're always searching for simpler things to do," says Dr. Brooks, but he believes the study currently raises more questions than answers.

Daniel Cook