What tumor markers should be ordered in suspected lung cancer or pulmonary metastasis?

From the Guidelines

For suspected lung cancer or metastasis to the lungs, the most useful tumor markers to order include carcinoembryonic antigen (CEA), cytokeratin 19 fragments (CYFRA 21-1), neuron-specific enolase (NSE), and pro-gastrin-releasing peptide (ProGRP), as recommended by the European Respiratory Journal 1. These markers should be interpreted alongside imaging studies and ultimately, tissue diagnosis remains the gold standard. Some key points to consider when ordering these markers include:

• CEA is elevated in many adenocarcinomas, while CYFRA 21-1 is particularly useful for squamous cell carcinomas.
• NSE and ProGRP are valuable for small cell lung cancer detection.
• Additional markers that may be helpful include CA-125, CA 19-9, and SCC (squamous cell carcinoma antigen).
• A comprehensive approach should also include complete blood count, comprehensive metabolic panel, and lactate dehydrogenase (LDH), which can indicate tumor burden and metastatic disease.
• Tumor markers are most valuable for monitoring treatment response and recurrence rather than initial diagnosis, as they may be elevated in non-malignant conditions like inflammation, infection, or organ dysfunction, potentially leading to false positives, as noted in the Journal of the National Comprehensive Cancer Network 1. It's also important to consider the latest guidelines from the National Comprehensive Cancer Network, which recommend a multidisciplinary approach to diagnosis and treatment, including the use of next-generation sequencing to detect actionable biomarkers 1.

From the Research

Cancer Markers for Suspected Lung Cancer or Metastasis to Lungs

The following cancer markers are relevant for suspected lung cancer or metastasis to lungs:

• CEA (Carcinoembryonic Antigen) 2, 3, 4, 5
• CYFRA 21-1 (Cytokeratin 19 fragment) 2, 3, 4, 5
• NSE (Neuron-specific enolase) 2, 3, 4, 5
• ProGRP (Pro-gastrin-releasing peptide) 2, 3, 4, 5
• SCC-Ag (Squamous cell carcinoma antigen) 2, 3, 4

Diagnostic Value of Cancer Markers

The diagnostic value of these cancer markers can be evaluated individually or in combination:

• CEA has a diagnostic sensitivity of 62.8% and a specificity of 93.1% for lung adenocarcinoma 4
• CYFRA 21-1 has a high diagnostic sensitivity for lung adenocarcinoma and squamous cell carcinoma 4
• NSE and ProGRP have high diagnostic sensitivity and specificity for small cell lung cancer 4, 5
• The combination of CYFRA 21-1 and CEA has a high sensitivity and specificity for diagnosing lung adenocarcinoma 4
• The combination of NSE and ProGRP has a high sensitivity and specificity for diagnosing small cell lung cancer 4, 5

Clinical Significance of Cancer Markers

The clinical significance of these cancer markers includes:

• Early diagnosis and differential diagnosis of lung cancer 3, 4
• Monitoring of disease progression and response to therapy 3, 5
• Evaluation of chemotherapeutic outcomes 3, 5