One in a Billion

Clinical trials under way at four cancer-treatment centers in the U.S. may revolutionize the way the second-leading cause of death in the U.S. is treated.

These revolutionary new trials are looking to detect the smallest trace amount of cancer cells in blood tests. There are more than a billion blood cells in circulation for every single tumor cell, according to Dr. Denis Haber, researcher at Massachusetts General Hospital in Boston. The new testing methods analyze a blood sample that is run across a microchip treated with a special glue. Only cancer cells "stick" to the glue, making this one-in-a-billion detection possible.

Doctors might also be able to tell how a patient is responding to treatment by utilizing the test. Biopsies, X-rays, CT scans and MRIs can take months to determine if treatment is working, according to Dr. Elmer Huerta, a former president of the American Cancer Society.

While these trials are confined to cancer patients, researchers are looking to potentially develop a similar blood test for seemingly healthy patients.