In addition, 78.69% of patients in the early stages (I and II) of disease could be diagnosed using a combination of CTCs, CEA, CA 125, CYFRA 21‐1, and SCC, and such an approach has excellent potential as a means of facilitating early cancer diagnosis that will influence patient treatment decisions in order to allow for the better management of lung cancer in the clinic. Here, CEACAM5 is linked to cancer.