CEACAM5 and cancer: Probst et al. [25] screened out 18,113 patients with LARC by selecting from the 2006–2011 National Cancer Data Base, 47% had elevated pretreatment CEA which was significantly associated with decreased pCR (OR = 0.65, p < 0.001), pathological tumor regression (OR = 0.74, p < 0.001) and downstaging (OR = 0.77, p < 0.001).