Is fecal occult blood testing more sensitive for left-sided than for right-sided advanced colorectal neoplasms? Literature review and evidence from a large screening study

Background: Fecal occult blood tests (FOBTs) are widely used for colorectal cancer screening. The aim of this study was to assess whether there is a difference in sensitivity of FOBTs for advanced colorectal neoplasms in the left versus the right colon. Methods: We systematically searched the literature for screening studies conducted in average-risk adults that performed a FOBT (immunochemical and/or guaiac-based) and colonoscopy among all participants and reported site-specific sensitivities of the FOBT for advanced colorectal neoplasms. We further analyzed fecal occult blood levels measured by an immunochemic…