CEACAM5 and colorectal cancer: To compare with other tumor markers, the widely accepted colorectal cancer biomarker carcino‐embryonic antigen (CEA) has a 41% to 97% sensitivity, which is somewhat higher, and a 52% to 100% specificity, which is comparable to that of S‐100B.19 A recent study revealed that 1.5% of all CEA measurements from curatively treated patients with stage I‐III colorectal cancer ultimately led to recurrence detection.20, 21 As with S‐100B, a normal CEA level does not exclude recurrent disease.22