Gene points way to noninvasive colon cancer blood test

Simply put, the sooner doctors can detect colon cancer, the better, because early detection boosts survival rates. The Yonsei University College of Medicine in Seoul, South Korea, and Genomictree believe they can accomplish this goal, thanks to a noninvasive biomarker blood test that appears to be highly accurate based on initial clinical work.

Their SDC2 methylation test of tumors, nontumor tissue, and blood samples from dozens of colorectal cancer and healthy patients works well enough to warrant further attention. According to their results, the test reached a 92% rate of detection for stage I colon cancer patients. It also spotted 87% of all stages of colon cancer and zeroed in on 95% of patients who didn't have any cancer. In other words, it was highly accurate and also worked with a robust rate of sensitivity. And Genomictree CEO Sungwhan An said in a statement that the results came from testing less than 1 ml of blood.

"We are very excited with this result using a small amount of serum DNA," he added, noting that future tests will involve larger blood samples with a goal of boosting clinical results even further. More testing is necessary to validate these numbers, of course, so the fact that work is advancing beyond these initial results is encouraging. Details are published in The Journal of Molecular Diagnostics.

Could this test be used instead of a colonoscopy, or at least in conjunction with one? Time will tell. But success here would be a big deal for colon cancer diagnosis and treatment, considering that the options to identify it are rather limited. As the research team notes, colorectal cancer diagnostic options come down to two kinds of fecal testing or a colonoscopy, but patients don't undergo these tests as often as they should. A biomarker blood test would make things easier and could be a better way to promote wider, more consistent colon cancer screening. That's important, because colon cancer is otherwise hard to diagnose unless a surgeon can go inside directly and look. And even then, fecal tests and colonoscopies both can miss things.

Why SDC2? Well, their biomarker search determined that the gene generated higher methylation levels in tumor tissue than in regular tissue. And it is also expressed in colon mesenchymal cells. But it isn't the only biomarker showing promise in the bid to better diagnose colon cancer. Scientists at Kyoto University in Japan, for example, identified the protein DCLK1 as a biomarker for colon cancer stem cells. And researchers from Imperial College London developed a urine test for gastroesophageal cancer biomarkers that they hope to test on colon cancer patients.

- read the release
- here's the journal abstract