In this study, 88.9% of the NSCLC patients were in the early stages (IA-IIB), and it was observed that CEA, NSE, and Cyfra21-1 exhibited lower diagnostic capabilities for early-stage NSCLC compared to late-stage lung cancer, complicating the differentiation of early-stage lung cancer patients from healthy individuals [15]. Here, CEACAM5 is linked to lung cancer.