Screening Test for Colon Cancer

There are multiple screening tests for colon cancer or colorectal cancer. According to the global systematic review of screening interventions and guidelines, there are three major tests including a colonoscopy, flexible sigmoidoscopy, and fecal occult blood test (FOBT) (Bénard, Barkun, Martel, & von Renteln, 2018). As the researchers note, there exists a variety of factors that influence the selection of a particular test. Among them, they recognize age, surveillance intervals, risk group, start/stop timing, and other aspects that might affect clinical decision making. In terms of recommendation strength that presupposes the complex measure of reliability, accuracy, and acceptability, grade A evidence supported the use of FOBT and immunochemical (FIT) especially, as well as computed tomographic colonography (CTC) (Bénard et al., 2018).

Another systematic review that tracked grade A-B evidence studies conducted by Lin et al. (2016) suggests that in terms of quality and prediction strength, one may not single out a specific screening intervention but a number of them. Instead, they argue that colonoscopy, flexible sigmoidoscopy, CTC, and FOBT are among the most prominent and reliable tests. All of those measurements differ depending on the assessed parameter, and there is currently no universal solution. As such, the highest accuracy and lowest mortality rates are detected in FOBT (both FIT and fecal DNA). However, it lacks specificity, while colonoscopy offers as high as 93% accuracy (Lin et al., 2016). CTC demonstrates the best sensitivity, yet it presents the risk of ionizing radiation. Thus, it seems that FOBT is one of the most suitable candidates for colon cancer screening as multiple studies regarded it as accurate and safe if specificity was set aside. Nonetheless, it should once again be noted that the clinical decision-making process should assess multiple variants depending on age, risk group, surveillance intervals, and other factors to select the most effective screening tool.


Bénard, F., Barkun, A. N., Martel, M., & von Renteln, D. (2018). A systematic review of colorectal cancer screening guidelines for average-risk adults: Summarizing the current global recommendations. World Journal of Gastroenterology, 24(1), 124-138.

Lin, J. S., Piper, M. A., Perdue, L. A., Rutter, C. M., Webber, E. M., O’Connor, E., … Whitlock, E. P. (2016). Screening for colorectal cancer: Updated evidence report and systematic review for the US preventive services task force. Journal of American Medical Association, 315(23), 2576-2594.