There is potentially exciting news about colon cancer screening. Urine tests, which have been used to some degree to help screen for prostate, bladder, breast, and lung cancer, may also be effective for detecting and diagnosing colon cancer.
A new study finds an increased level of metabolized tryptophan, one of the 22 amino acids found in proteins, in the urine of colon cancer patients. Earlier, related studies found certain estrogen metabolites present in the urine of women with breast cancer. These metabolites react with DNA, causing damage that may initiate events leading to breast and other cancers.
New Science
This research is part of a new field of science called metabolomics. When our body digests food, it produces molecular byproducts called metabolites. Metabolomics, then, is the study of these metabolites. By studying the unique chemical patterns that result from metabolic breakdown, scientists can see which ones change in people who have disease.
As scientists learn to characterize molecular changes associated with colon cancer development and progression, they will be better able to identify biological markers and relevant molecular targets for prevention and treatment.
Colon Cancer Screening
Although physicians can use one or more available tools to screen for colon cancer, a urine screening test would be a definite advantage.
Currently, the colonoscopy is the preferred screening tool for colon cancer. Unfortunately, however, only about half of people who should be screened for colon cancer, are, and not everyone is a candidate for this procedure. In addition to looking for the presence of cancer, physicians use colonoscopies to remove pre-cancerous polyps on the colon wall before they have a chance to develop into cancer. As with all other medical procedures, colonoscopies do pose some health risks.
There are other tools for detecting colon cancer. A sigmoidoscopy is similar to a colonoscopy, but does not require as much preparation. Physicians can only view the lower third of the colon during a sigmoidoscopy. Fecal Occult Blood Tests detect microscopic blood in the stool that may be a sign of cancer.
The National Cancer Institute estimates there will be almost 103,000 new colon cancer patients in 2010, so although this colon cancer research is still in the early stages, we can hope that someday we may have a urine test that both screens for colon cancer and helps determine how effective treatment is.
Sources
National Cancer Institute. "Colon and Rectal Cancer." Web. http://www.cancer.gov/cancertopics/types/colon-and-rectal
Qiu, Yunping, Cai, Guoxiang, Su, Mingming, Chen, Tianlu, Liu, Yumin, Xu, Ye, Ni, Yan, Zhao, Aihua, Cai, Sanjun, Xu, Lisa X. and Jia, Wei. "Urinary Metabonomic Study on Colorectal Cancer. Journal of Proteome Research 9 (3) (2010):1627-1634. Web.
