Detecting Fecal K-ras And P-53 Mutation In Patients With Colorectal Cancer

Background and aims: Colorectal cancer (CRC) remains the second leading cause of malignant mortality in industrialized countries, accounding for more than 10% of all cancer deaths. During the development of our country's economy and gradually western diet structure,mortality of colorectal cancer continue increases annually, and reach to the fouth in malignant disease in population, to the second in men. It would take about 10 years for normal colonic epithelium to become adnomas and then become carcinomas, so it provide enough time to screen and diagnose. However, because its asymptomatic in early stage and the performance limitations and low compliance rates with current screening tools, screening efforts had little impact on its mortality and morbidity. Colonoscopy and sigmoidoscopy are highly specific and sensitive tests for neoplasia, but they are invasive, and limited by patient compliance and physician availability. Also, they have risk for bleeding and perforation. Annual fecal occult blood test (FOBT) is a noninvasive and simple examination that has been shown to reduce the incidence , mortality and morbidity of CRC. But many cancers and most premalignant adenomas do not bleeding and are missed. Furthermore , high false-positive rates as a result of frequene and trivial sources of occult bleeding lead to unnecessary colonoscopies,which drive up programmatic costs. More optimal screening tools are needed that would exhibit the combined features of high sensitivity and specificity for early stage cancers, broad acceptability by general population, affordability and safety .