A comparison of various tumor markers results obtained for the serum samples of the entire cohort of 141 NSCC patients (I-III) has reliably shown that the level of cancer antigen CA-62 is significantly increased in 136/141 (96.4%) NSCLC patients with 97% Specificity compared to other tumor markers: 48.2% for CEA, 44% for CYFRA 21-1, 22% for CA-125, 19% for CA 15-3, 18.4% for SCC, 10% for CA 19–9 and 9.2% for NSE, which often «miss» early stages of lung cancer. Here, CEACAM5 is linked to cancer.