The test only detects whether blood is oozing from an advanced cancerous cell, but the presence of blood could also be a result of other non-cancerous conditions, such as a benign polyp or an abnormal blood vessel. The new DNA test instead collects cells shed from the lining of the colon and amplifies the genetic material, looking for indications of mutations at those earlier stages of cancer. The DNA test currently looks at seven specific genes previously identified by researchers as being identified with colon cancer. As new cancer-linked genes are identified, they could be added to the test, Ahlquist says. When these genes, such as the P53 and the k-RAS genes are mutated, they can cause a loss in a piece of a chromosome or cause cells to lose their ability to correct errors in the genetic sequence, resulting in abnormal cell growth.
Doctors can use colonoscopy to remove problematic growths in patients found to have the mutations.
The DNA test picked up 91 percent of the patients with cancer and 73 percent of the patients with polyps. Those without colon cancer were also diagnosed correctly as healthy. The researchers were not aware of the patients' status when they performed the test. They will use the technique on 3,000 patients at average risk for colorectal cancer at six different medical centers nationwide. It's very important that people don't put too much emphasis on future promise and procrastinate doing anything now.