What is this test?
CYFRA 21-1 measures fragments of cytokeratin 19. It may help monitor some lung cancers and other epithelial cancers.
Why might it be ordered?
- To monitor treatment or progress in certain types of established cancer, most commonly lung.
- As supporting information alongside imaging and other tests when requested by an oncologist.
What sample is needed?
A healthcare professional collects a venous blood sample. Depending on the method, the laboratory uses serum or plasma.
How should you prepare?
Tell the laboratory about all medicines, hormone treatments, vitamins and supplements you take. Do not stop or change treatment unless your clinician tells you to. Follow any instructions about fasting and the time of collection.
How should you understand the result?
There may also be an increase in benign lung diseases, inflammation or reduced kidney function. A trend across consecutive measurements made with a comparable method is often more informative than a single value.
Sources and editorial status
This patient-facing text is an editorial draft. It should be approved by a laboratory physician before official publication.