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Lung cancer markers: how laboratory diagnostics helps detect oncopathology
Respiratory cancers, including lung cancer, remain among the most common and deadly in the world. According to WHO, more than 2 million new cases are registered every year. Early diagnosis is the key to successful treatment, and this is where tumor markers — specific substances that may indicate the presence or progression of a malignant process.
What are tumor markers in lung cancer?
Tumor markers are proteins or other molecules that are produced by cancer cells or the body in response to a tumor. They are found in the blood, urine, or other body fluids. In lung cancer, markers are not uniquely specific, but they can be useful for assessing risk, monitoring the disease, and controlling treatment.
Main markers used in lung cancer
1. CEA (carcinoembryonic antigen)
It is used to detect adenocarcinomas. It can also be elevated in other cancers and some non-cancer diseases, but levels are often significantly elevated in lung cancer.
2. CYFRA 21-1 (cytokeratin fragment 19)
Particularly sensitive to non-small cell lung cancer, particularly squamous cell carcinoma. Often used to assess the effectiveness of therapy.
3. NSE (neurospecific enolase)
Most common in small cell lung cancer. Used to diagnose and monitor disease progression.
4. ProGRP (prochromogranin A)
A newer marker that detects small cell carcinoma with higher specificity than NSE.
5. SCC (squamous cell carcinoma antigen)
Characteristic of squamous cell carcinoma. Its level may indicate tumor size or recurrence.
Auxiliary markers and combinations
Doctors often use combined marker panel, to improve diagnostic accuracy. For example:
CYFRA 21-1 + CEA — for non-small cell lung cancer
NSE + ProGRP — for small cell
Additionally, TPS (tissue polypeptide antigen), TPA, β-HCG can be evaluated
When is a lung cancer marker test prescribed?
If symptoms are present: prolonged cough, blood in sputum, shortness of breath, chest pain
At-risk groups: smokers, workers in hazardous industries, people with a heavy hereditary history
To monitor the effectiveness of treatment
To detect recurrence after surgery or chemotherapy
Advantages and limitations
Tumor markers are a tool that complements, but does not replace other diagnostic methods (CT, biopsy, bronchoscopy). They can be false positives with infections, autoimmune disorders or due to smoking.
Comparison table of main lung cancer markers
| Tumor marker | Type of lung cancer | Sensitivity | Specificity |
|---|---|---|---|
| CEA | Adenocarcinoma | Medium | Low |
| CYFRA 21-1 | Squamous cell, NSCLC | High | Medium |
| NSE | Small cell | Medium | Medium |
| ProGRP | Small cell | High | High |
| SCC | Squamous cell | Medium | Medium |
How to take the test correctly
Blood is donated on an empty stomach.
Do not consume alcohol and fatty foods during the day
Report any medications or concomitant diseases
In dynamics - take the test under the same conditions and in the same laboratory
Tumor markers are particularly valuable not for primary diagnosis, but for monitoring the effectiveness of treatment and timely detection of relapse.
In medical practice, an experienced oncologist combines marker results with imaging findings, clinical features, and histological confirmation. Self-interpretation of tumor marker levels without medical advice is inappropriate and potentially misleading.
