Plasma ctDNA in Patients Undergoing Diagnostic Colonoscopy

Overview

When the DNA inside of human cells undergoes certain alterations (mutations), the cells may develop into a cancer. The cancer cells may shed this DNA into the blood stream. This circulating tumor DNA (ctDNA) can be detected by very sensitive, specialized laboratory tests. Measurement of ctDNA has been shown to be useful for following patients with known cancer. It has also been found in the circulation of some patients with early stage cancer. The purpose of this study is to examine blood specimens for the presence of ctDNA in individuals without known cancer who are scheduled to undergo a screening or diagnostic colonoscopy in order to see if the ctDNA test can detect a cancer or precancerous condition at a very early stage before the patient becomes symptomatic. The results of this study should help define the role of ctDNA in the detection of early stage colon cancer and to define how sensitive it is (i.e. how well it picks up cancer when it is present) and how specific it is (i.e. how often is ctDNA found in patients with benign diseases or no abnormalities).

After the participants have undergone the informed consent process, they will have 30 milliliters (approximately two tablespoons) of blood drawn. This will be done prior to their scheduled screening or diagnostic colonoscopy. If the patient has indicated a desire to receive the results of their test, they will receive a written description, as will their primary care physician. The patients will be contacted yearly for up to 5 years by the study staff to learn whether they have been found to have a diagnosis of colon or other cancer.

Conditions