Recently, some prognostic factors such as intratumoral blood vessel invasion (IVI), intratumoral lymphatic invasion (ILI), visceral pleural invasion, tumor size, and serum level of carcinoembryonic antigen (CEA), have been proposed in order to identify poor prognostic factors providing beneficial adjuvant chemotherapy for stage I NSCLC patients. Here, CEACAM5 is linked to neoplasm.