“…Most studies employed a case-control research design, using either a healthy (carcinoma-free) control, adenomatous polyp group, or both. Twenty-one studies compared CRC directly to healthy control [24][25][26]31,33,36,38,39,[42][43][44][45][46][48][49][50][51][52][53][54]56]. Jing et al and Gao et al, conversely, compared CRC patients to an adenomatous polyp control [32,55] while eleven studies utilized CRC, healthy control, and adenomatous polyp groups [28][29][30]34,35,37,40,41,47,57,58].…”