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.

Table 2 Comparison of therapeutic biomarkers

Types	Clinical relevance	Associated therapeutic strategies	Drugs
EGFR[43]	Lung adenocarcinoma has a substantially greater rate of EGFR mutation than lung squamous cell carcinoma	First-line treatment drugs for NSCLC patients with EGFR sensitive gene mutations	Osimertinib, Almonertinib, Furmonertinib, Befotertinib, Gefitinib
ALK[44]	ALK positive NSCLC patients are usually young, non-smoking, and EGFR non mutated lung adenocarcinoma populations	For advanced NSCLC patients accompanied by ALK gene fusion	Crizotinib, Alectinib, Ensartinib
ROS1[45]	ROS1-positive lung cancer is commonly found in young, non-smoking, or lightly smoking lung adenocarcinoma patients	For ROS1 positive NSCLC patients	Crizotinib, Entrectinib, Lorlatinib, Cabozantinib
PD-1/ PD-L1[46]	PD-1/PD-L1 inhibits T cell function via the TCR receptor signaling pathway, leading to immune escape in tumors	For driver gene negative advanced NSCLC patients	Nivolumab, Pembrolizumab, Camrelizumab, Tislelizumab, Sintilimab, Durvalumab, Atezolizumab
CLTA-4[47,48]	CLTA-4 facilitates tumor immune evasion	For advanced and metastatic NSCLC patients	Ipilimumab, Tremelimumab, Cadornilimab

EGFR: Epidermal growth factor receptor; ALK: Anaplastic lymphoma kinase; ROS1: C-ROS proto-oncogene 1; PD-1/PD-L1: Programmed death-1 and its ligand; TCR: T cell receptor; CTLA-4: Cytotoxic T-lymphocyte-associated protein.