In the newly published study, Jia and colleagues searched for more than 500
metabolites in urine samples from 60 patients with colon cancer and 63 people
without the disease.
They identified more than a dozen substances that were altered in the
patients, including significant disturbances in the expression of tricarboxylic
acid (TCA), which regulates energy metabolism, and elevated levels of the amino
Some of the alterations were also seen in rats with colon cancer.
The research appears in the latest issue of the American Chemical Society's
Journal of Proteome Research.
Jia says further studies could determine if the metabolite expression
differs among patients with colorectal cancer at different stages of the
If this is the case, urine analysis could prove useful for assessing how
well patients are responding to treatments, he says.
American Cancer Society spokesman Michael H. Melner, PhD, says such a test
is, at best, many years away if it happens at all.
Melner serves as scientific program director for molecular genetics and
biochemistry for the American Cancer Society.
"This is an interesting first step, but this research is very preliminary,"
he tells WebMD. "I would hesitate to say anything about the potential for a
urine test to detect colorectal cancer based on this research."
Potential Tests for Other Diseases
Melner says there is much excitement about metabolomics within the cancer
"Many different groups are utilizing this technique to explore altered
metabolism within tumor cells," he says.
He cites research from the University of Michigan in which metabolomics was
used to identify a possible biomarker for prostate cancer progression.
The metabolite sarcosine was not present at all in the urine of people
without prostate cancer. Levels tended to be low in patients with less
aggressive disease and high in those with advanced cancer.
Another research team from St. Louis' Washington University School of
Medicine recently identified protein biomarkers for kidney cancer that could
one day lead to a urine test for that disease.
Lead researcher Evan D. Kharasch, MD, PhD, says kidney cancer patients
expressed high levels of two proteins -- AQP1 and ADFP.
"Levels were elevated 10- to 100-fold compared to people who did not have
kidney cancer," Kharasch tells WebMD,
But this research is also very early, and it is not yet clear if the
proteins are also elevated in people with other kidney diseases.