What are all the tumor markers for lung cancer?

From the Guidelines

Lung cancer tumor markers include several key biomarkers used for diagnosis, prognosis, and treatment monitoring, with the most clinically significant markers being carcinoembryonic antigen (CEA), cytokeratin 19 fragment (CYFRA 21-1), neuron-specific enolase (NSE), progastrin-releasing peptide (ProGRP), and squamous cell carcinoma antigen (SCC-Ag) 1. The most recent and highest quality study, published in 2018, highlights the importance of immunohistochemical markers in the subclassification of non-small cell lung carcinoma (NSCLC) 1. Some key points to consider when evaluating tumor markers for lung cancer include:

• CEA is elevated in various cancers, including adenocarcinomas of the lung, while CYFRA 21-1 is particularly useful for non-small cell lung cancer (NSCLC), especially squamous cell carcinoma.
• NSE and ProGRP are more specific for small cell lung cancer (SCLC).
• Additional markers include cancer antigen 125 (CA-125), tissue polypeptide antigen (TPA), and tumor-associated glycoprotein 72 (TAG-72).
• Molecular markers like EGFR mutations, ALK rearrangements, ROS1 fusions, BRAF mutations, PD-L1 expression, and KRAS mutations are crucial for targeted therapy selection. These molecular markers help identify patients who may benefit from specific treatments like tyrosine kinase inhibitors or immunotherapy, and should be interpreted alongside clinical findings, imaging studies, and histopathological examination for accurate diagnosis and treatment planning, as no single marker offers complete diagnostic certainty 1. It is also important to note that the current WHO guidelines for the classification of lung cancer provide diagnostic terminology and classification criteria for lung tumors, and serve as a foundation for appropriate clinical management and the development of clinical trials 1. In terms of the role of circulating markers in assessing overall survival, some studies suggest that post-therapy CEA normalization or significant decrease may be related to better survival in early-stage NSCLC treated by surgery, advanced NSCLC with chemotherapy, and after salvage gefitinib in relapsing NSCLC 1. However, it is essential to consider the quality of evidence and the grade of recommendation when interpreting these findings, as the level of evidence is often retrospective and the grade of recommendation may be limited 1. Overall, the use of tumor markers in lung cancer diagnosis and treatment planning is a complex and evolving field, and healthcare providers should stay up-to-date with the latest research and guidelines to provide the best possible care for their patients.

From the Research

Tumor Markers of Lung Cancer

• Carcinoembryonic antigen (CEA) 2, 3, 4, 5, 6
• Squamous cell carcinoma antigen (SCC-Ag) 2, 3, 5
• CYFRA 21-1 2, 3, 4, 5, 6
• Neuron-specific enolase (NSE) 2, 3, 5
• CA 125 3, 6
• ProGRP 5

Sensitivity and Specificity of Tumor Markers

• CYFRA 21-1: sensitivity 43-76%, specificity 68-89% 3, 4, 5
• CEA: sensitivity 52-69%, specificity 68-91% 3, 4, 5
• SCC-Ag: sensitivity 33-85%, specificity not reported 3, 5
• NSE: sensitivity 22-28%, specificity not reported 2, 3, 5
• CA 125: sensitivity 55%, specificity not reported 3
• ProGRP: sensitivity not reported, specificity not reported 5

Clinical Significance of Tumor Markers

• Tumor markers are not suitable for diagnosis, but are useful for monitoring therapy and prognosis 2
• Combined detection of serum markers can improve diagnostic accuracy and sensitivity 5
• Tumor markers can provide additional prognostic value in NSCLC patients with stable disease at first CT scan 6