What is CYFRA 21-1?
CYFRA 21-1 is the abbreviation for cytokeratin 19 fragment. Cytokeratins (cytokeratins) are stable, fiber-like proteins that form the cellular framework. This truss-like structure contributes to the stabilization and shape of a cell.
There are 20 types of cytokeratins, each of which occurs in different types of cells in the body. When such a cell dies, fragments of the cytokeratins are released and are detectable in the blood.
CYFRA 21-1 is found primarily in the covering cells (epithelia) of the bronchial mucosa. This mucosa lines the airways (bronchi). It is constantly renewing itself. Therefore, it is normal for old cells to die and release components such as CYFRA 21-1. So a low level of this marker is not a concern.
When to determine CYFRA 21-1?
CYFRA 21-1 is an important tumor marker in lung cancer, especially in non-small cell lung cancer. However, it is not suitable for diagnosis! The measured value is not changed (increased) in every patient. In addition, other diseases can also influence CYFRA 21-1.
In lung cancer, the determination of CYFRA 21-1 rather serves the following purposes:
- As the disease progresses, a falling or rising CYFRA 21-1 value indicates how well the tumor is responding to therapy. If the value drops sharply, the tumor shrinks.
- After therapy has been completed, CYFRA 21-1 is measured in order to detect a recurrence (relapse) at an early stage. If the value suddenly rises again years after treatment, this is probably due to renewed tumor growth.
Doctors also determine the CYFRA 21-1 value in other cancers (such as bladder cancer) and in some benign diseases.
What are the normal values for CYFRA 21-1?
In small amounts, CYFRA 21-1 can also be detected in healthy people, as it is a normal product of the respiratory mucosa. Therefore, there is only one upper limit: in healthy adults, the CYFRA 21-1 level in blood serum is below 3.0 nanograms per milliliter (ng/ml). However, depending on the laboratory and the test method, the reference range may differ slightly.
When is the CYFRA 21-1 level too high?
Since cytokeratins are assigned to specific cells, if the value is elevated, we know that many cells of this type have been destroyed. CYFRA 21-1 focuses on the airway mucosa: Particularly high levels of the marker can be detected, for example, when the airway mucosa is inflamed and many mucosal cells die.
Also, when cells of the bronchial mucosa grow excessively due to cancer development, a large amount of CYFRA 21-1 enters the blood. Therefore, especially in bronchial carcinoma, the CYFRA 21-1 level is usually elevated.
- Lung cancer (especially non-small cell bronchial carcinoma)
- Urinary bladder cancer
- Pneumonia (lung inflammation)
- diseases of the gastrointestinal tract
- gynecological diseases (cervical cancer)
- urological diseases
So, the CYFRA 21-1 value increases in some cancers, but it is also elevated in some more harmless diseases.
When is the CYFRA 21-1 value too low?
There is no such thing as a CYFRA 21-1 value that is too low. This means that deviations below the maximum value are not medically significant.
What to do in case of elevated CYFRA 21-1 values?
CYFRA 21-1 is not determined as a routine parameter. Physicians measure this value mainly in lung cancer patients in order to monitor the course of the disease and the success of the therapy.
If you have an elevated CYFRA 21-1 value, consult your physician.
Caution: A high CYFRA 21-1 value does not necessarily indicate cancer.
