A tumor marker associated with lung and certain other cancers.
Cyfra 21-1 measures a fragment of cytokeratin 19, a structural protein inside epithelial cells. When these cells break down, the fragment is released into the blood.
It is used as a tumor marker, most often linked to lung tissue. Small amounts are present in healthy people.
Cyfra 21-1 is used mainly to monitor people diagnosed with non-small cell lung cancer, to follow treatment and check for return, alongside imaging. It is not a screening test for healthy people.
Mild rises can come from benign lung and other conditions, and from reduced kidney function. A high or rising level needs a doctor to interpret in the full clinical picture.
Aniva reads your result against research-backed ranges, not just the lab's wide normal. The reference shown below is specific to this biomarker.
Ranges are guidance only. Cyfra 21-1 is an upper-cutoff marker.
| Group | Common upper guide (SI) |
|---|---|
| Adults | up to about 3.3 µg/L (ng/mL) |
The exact cutoff depends on the assay. Aligned to German laboratory practice (DGKL).
Benign lung disease, other inflammatory conditions, and reduced kidney function can raise Cyfra 21-1. Results from different assays are not interchangeable, so trends should be followed on the same method.
Sometimes read alongside CEA and, for small cell lung cancer, NSE, and always with imaging.
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