Between 2007 and 2020, the National Comprehensive Cancer Network (NCCN) recommended post-treatment colonoscopy one year after primary rectal cancer therapy while physician visits, carcinoembryonic antigen (CEA) tests and pelvic computed tomographic colonography (CT) were recommended every 3-6 months in the first two years after primary rectal cancer therapy [10]. This evidence concerns the gene CEACAM5 and rectal cancer.