Hitting the Methylation Marks

A DNA-based colon cancer test may help to diagnose the disease earlier, reports the New York Times. Instead of relying on mutational testing, a new test from Madison, Wis.-based Exact Sciences looks for highly methylated DNA. In cancer cells, the Times says, DNA is usually less methylated, except for certain spots "where the methylation process is taken to excess, perhaps because the cells need to shut down tumor suppressor genes." And so, Exact's test looks at the methylation of four markers, and was, the Times adds, 100 percent accurate in a lab test — though it is expected to be less accurate when tested using real-world stool samples.