Diagnosis and treatment of lung cancer: A molecular perspective

Table 1 Comparison of diagnostic biomarkers

Types	Function	Specificity	Efficacy assessment
CTCs[27-29]	CTCs can identify all types of tumor cells and can be detected at early stages of lung cancer	High specificity	The number of CTCs is highly consistent with the therapy efficacy
ctDNA[26,30]	ctDNA serves as an independent molecular marker for NSCLC and allows for the optimization of clinical staging in the early to middle stages and monitor early metastasis	High specificity	ctDNA indicates the patient's response to treatment earlier than imaging examinations
CEA[15,16,31]	CEA is expressed at high levels in NSCLC and increases with the progression of clinical staging	Broad-spectrum but low specificity	Effective treatment can restore serum CEA concentration to baseline levels
cRNA[32,33]	An indicator of tumor proliferation and migration	High specificity	Up-regulation of cRNA is related to poor prognosis

CTCs: Circulating tumor cells; ctDNA: circulating tumor DNA; CEA: Carcinoembryonic antigen; cRNA: circulating RNA.