Cancer cells have unique DNA signatures that can be detected even before the cancer is visible. In the case of colon cancer, these cells are shed into the waste stream by precancerous polyps or cancerous tumors that typically protrude from the colon wall. Tumors also may bleed into the colon.
The Exact Sciences’ colon cancer screening test combines powerful DNA biomarkers with FIT, or a fecal immunochemical test. The biomarkers will detect if DNA released by a precancer or cancer is present in the sample, while FIT will detect whether or not there is blood in the sample, potentially from a bleeding tumor. Combining DNA markers with FIT enables the company to deliver a more accurate test to patients, physicians and clinical laboratories.
The Exact colon cancer screening test has a number of significant benefits. First, it detects both precancer and cancer at projected sensitivities of greater than 50 percent and approximately 85 percent, respectively. Second, it is non-invasive, and does not require bowel preparation, making the test capable of dramatically increasing the low colorectal cancer screening rates in the United States. Third, the test is accessible and affordable. The sample can be returned by mail and the test will cost far less than a colonoscopy.
Exact Sciences’ solution will change colon cancer screening dramatically. Through the early detection of precancer and cancer with the company’s test, affected patients can be referred to colonoscopy, during which the polyp or lesion can be removed. This new model for colon cancer screening can significantly reduce colon cancer deaths through early detection. The earlier the detection, the greater the reduction in the 600,000 deaths around the world from colon cancer each year.
Other screening models point directly to how successful early detection can be in reducing mortality. The Pap test, for example, is the most widely-used cancer screening technique in medical history. It gained broad acceptance beginning in the 1950s and enables the examination of cells collected from the cervix to detect both precancer and cancer. As a result of screening for both precancer and cancer, cervical cancer mortality was reduced 74 percent from 1955 to 1992. The Exact colon cancer screening test will enable the same combination of precancer and cancer detection that the Pap test has offered for more than 65 years.
Exact Sciences will conduct an important pre-clinical validation study of its screening test in 2010. The pre-clinical study will be conducted both at Exact and an independent lab, and will assess and validate the performance of the company’s test across more than 2,000 subjects. Exact expects to see externally-generated data in the second half of 2010. During the second or third quarter of 2011, Exact anticipates beginning the clinical trial for its screening test. The company anticipates making its FDA submission in 2012.
