We classified the NSCLC patients into early-stage patients (stage I, n = 17) and middle- and late-stage patients (stage II-IV, n = 43) in the light of their clinical stages and analyzed the value of FTO and CEA, as well as CYFRA21-1, in diagnosing early NSCLC by drawing ROC curves. Here, CEACAM5 is linked to non-small cell lung carcinoma.