The Science Behind Stool-Based DNA Screening

Over the past decade, intense research has shown the underlying basis of colorectal cancer to be an accumulation of genetic alterations. Approximately 75% to 85% of colorectal cancers are not inherited, but rather a disease of the genome, which means every cancerous cell has some genetic alteration. This knowledge of genomics forms the basis of this new method of colorectal cancer (CRC) screening. Known DNA alterations associated with screen relevant neoplasia can be identified.

The graphic below illustrates groundbreaking work by Dr. Bert Vogelstein, the leader in the field of cancer genetics.

This Vogelgram, as it is called, details the specific molecular events of carcinogenesis - the transition of a normal cell in the epithelial lining of the colon through early and late adenoma and early and late cancer. Specific DNA alterations (APC, K-ras, p53 and BAT-26) occur as discrete steps in this cascade. By identifying these stages, Dr Vogelstein's work has allowed the development of a DNA analysis technique based largely on these genetic markers of screen relevant neoplasia found in the DNA recovered from rapidly growing cells in cancers and adenomas shed into the large bowel lumen and passed in the feces.