Screening for colorectal cancer using stool.
Extract: Colorectal cancer (CRC, cancer of the large bowel) is the third commonest malignancy worldwide. There were 945,000 new cases and 492,000 deaths in the year 2000. Lifetime risk of CRC is approximately 1 in 18 and risk rises with age. Many patients present with advanced disease, when chances for curative treatment are low. For these reasons an effective screening test would have substantial clinical benefits. Most CRCs are thought to arise from benign tumors, known as adenomas, over an interval of at least 5-10 years. Moreover, the average time for an asymptomatic early CRC to become an advanced symptomatic CRC is thought to be around 2-3 years. Survival is closely related to the stage at which the cancer is discovered (i.e., how advanced a tumor is), with early CRC having an excellent outcome. CRC has several properties that make it ideally suited for early detection by screening asymptomatic people. It has recognizable early stages and a defined natural history. Surgical treatment is effective, with greater benefit in early stage disease. Removal of pre-malignant adenomas is also feasible using endoscopy; and screening tests are currently available.
Davies
R Justin
RJ
Medical Research Council Cancer Cell Unit, Hutchison/MRC Research Centre, Hills Road, Cambridge, CB2 2XZ, UK.
Miller
Richard
R
Coleman
Nicholas
N