A team of researchers recently discovered a novel noninvasive method that could provide early-stage diagnosis of colorectal cancer. They identified a class of molecules in mouse model feces that point to the presence of precancerous polyps.
The study report, “The Fecal Metabolome in Hmga1 Transgenic Mice with Polyposis: Evidence for Potential Screen for Early Detection of Precursor Lesions in Colorectal Cancer,” was published in the Journal of Proteome Research.
The research was conducted by Herbert Hill and Michael Williams of Washington State University (WSU) who collaborated with Raymond Reeves from the WSU School of Molecular Biosciences and Linda Resar from Johns Hopkins University School of Medicine.
According to the authors, a “metabolic fingerprint” that matches changes in both mouse and human colon tumor tissues suggests that the novel diagnostic tool could possibly be used for early detection of colorectal cancer.
Early diagnosis is critical for colorectal cancer patients but most current tests are limited by lack of access and simplicity. For example, a colonoscopy is considered a lifesaver tool but the procedure is expensive and invasively difficult for most people.
Williams believes that the new procedure would be much easier and provide more information.
“With our new test, it could be possible to diagnose cancer occurring throughout the entire colon,” Williams said in a press release.
Hill and Williams discovered the “molecular fingerprint” while using an ion mobility-mass spectrometry (IMMS). The tool is used globally in ultrasensitive sensor devices to detect illegal drugs, chemical warfare, and explosives.
The researchers coupled IMMS with a particles separation technique to identify metabolic products from normal colon tissue in humans and mice, including fats, enzymes, glucose, and amino-acids. Then the scientists compared the normal profiles to those of cancerous colon tissues from human and mice, and with profiles from mice with colon polyps. Mouse colon polyps are reportedly identical to those found in humans.
In the two different cases, the scientists found that colon cancer changed fat metabolism significantly, especially in lipids and fatty acids. These created the “metabolic fingerprint” shared between humans and mice.
The researchers then analyzed stool samples from mice to see if the “fingerprint” could be found there. It was. The IMMS tool was capable of detecting several metabolic abnormalities and clearly distinguishing between healthy mice and mice with colorectal cancer.
“The feces were not exactly the same as the tissue samples, but it had a lot of similarities to the tissue,” Hill said. “We found the lipids and fatty acids were changing — and there were also changes in the amino acids.”
Specifically, a class of fats called lysophospholipids changed dramatically.
“These types of lipids are known to be important in the development of cancer and are particularly tied to colorectal cancer,” Williams said.
The finding could be a groundbreaking start to developing a new, more user-friendly method for diagnosing colon cancer in early stages, according to the study results.
“The benefit of early detection is that we can catch cancer before it metastasizes to other parts of the body,” Williams said. “Our results represent the zero stage of cancer, the polyp stage — as early as colon cancer can be detected.”
Hill said the most exciting part of the study is being able to see differences in the stools.
“This could lead to a noninvasive, more comprehensive early warning detection method for colorectal cancer, but a lot of research needs to be done before it can be actually realized,” Hill said.
Researchers hope to next evaluate human stool samples in order to confirm the fingerprint patterns in people with colorectal cancer. The researchers are already looking for funding to conduct the study.
