Scientists are close to developing a urine test for detecting colon cancer.
Such a test could compliment or even reduce the need for colonoscopy, the mainstay screening test used to diagnose the disease currently.
The study, conducted by Wei Jia and colleagues, analyses chemical differences in the urine of humans with and without colon cancer.
The researchers point out that colonoscopy, which involves using a flexible, lighted tube to see inside the colon, is the most effective tool for the early screening of colon cancer.
However, the procedure is unpleasant, costly, and time-consuming.
A urine test could provide an alternative method, according to the scientists.
For the study, the team analysed urine samples from 123 people - 60 with colon cancer and 63 without - for differences in its composition.
They identified 16 substances that appear in unusual amounts in colon cancer.
The changes include increased levels of tryptophan, one of the 22 amino acids found in proteins.
The study team said results show the potential of using urine as a tool for diagnosing colon cancer.
The study has appeared in ACS' Journal of Proteome Research.