CYFRA 21-1

Immunology

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Description

The main application of all tumour markers is monitoring for relapse or progression. Use as a diagnostic aid requires care and knowledge of the test limitations. Opportunistic screening is discouraged [1]. CYFRA 21-1 measures a fragment of cytokeratin 19, which has a molecular weight of 30 KDa. Cytokeratins are structural proteins which form the subunits of epithelial intermediary filaments. They have specific distribution patterns, which makes them of use in the differentiation of tumour origin [3]. The main indication for the CYFRA 21-1 marker is in monitoring the course of non-small cell lung carcinoma (NSCLC). CYFRA 21-1 should not be used in the primary diagnosis of lung carcinoma. Successful treatment will lead to a rapid decrease in CYFRA 21-1 concentration in NSCLC. Constant or small reductions in concentration may indicate incomplete removal of the tumour or the presence of multiple tumours. An increase in CYRFA 21-1 may indicate progression of the disease, this can occur prior to a change in clinical symptoms. Studies have shown that CYFRA 21-1 may be of use as a marker of cervical cancer. It has been shown that CYFRA 21-1 has a lower sensitivity (63%) for cervical cancer than SCC (66%) [4]. However it has been demonstrated that CYFRA 21-1 concentration can correlate with tumour size although the test should not be used for diagnosis. Reductions in concentration may be seen with successful therapy [2]. Slightly raised levels may be seen in benign liver disease and renal failure.

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Indications

Main indication is in the monitoring of non-small lung cell cancer (NSCLC), may also be used in the monitoring of cervical cancer.

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Sample Type

2mL Serum (Gel 5mL Yellow tube) or 2mL Plasma (Lithium Heparin or EDTA). Requests from outside Sheffield: Transport at ambient temperature via Royal Mail or Courier.

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Reference Range

<3.3 ng/mL.

Reference range derived by manufacturer and verified by in-house validation.

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Turnaround Time

Within 5 days

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Testing Frequency

Weekly

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External Notes

Cyfra 21-1 has replaced SCC for use in monitoring small cell lung cancer and cervical cancer. The test has not been shown to be useful in monitoring penile cancer. Tumour Markers are not diagnostic and are of most use in monitoring response to treatment and early detection of relapse. Normal values do NOT exclude malignancy.

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References

Sturgeon CM et al. Serum Tumour Markers:How to order and interpret them. British Medical Journal. 2009. 339:852-858. [Ref 1]
Pras E et al. Serum squamous cell carcinoma antigen and CYFRA 21-1 in cervical cancer treatment. Int J Radiation Onc Biol Phys. 2002. 52(1):23-32. [Ref 2]
Pastor A et al. Diagnostic value of SCC, CEA and CYFRA 21.1 in lung cancer: a Bayesian analysis. Eur Respir J. 1997. 10:603-609. [Ref 3]
Kainz C et al. Cytokeratin subunit 19 measured by CYFRA 21-1 assay in follow up of cervical cancer. Gyne Onc. 1995. 56(3):402-405. [Ref 4]

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Please note: the above information is subject to change and we endeavour to keep this website up to date wherever necessary.