“…Cancer surveillance is aimed at detecting recurrences of the cancer amenable to further curative treatment, screening for new tumors or polyps, and detecting metastatic sites before patients present with symptoms. Two meta-analyses reported that conducting post-treatment surveillance through procedures including serum carcinoembryonic antigen (CEA) testing, endos-copy, physical examination, and computed tomography (CT) imaging was associated with the beneficial outcomes of a lower overall mortality rate, earlier detection of recurrences, and better chances of curative re-resection [4,5]. However, a substantial proportion of CRC patients do not undergo routine cancer surveillance following curative surgery [6 -11].…”