Turnaround times
The quoted turnaround time is from sample receipt in the laboratory, to results authorisation in the Laboratory Information Management system. The times do not include transport of specimen to the laboratory or the administrative process to print and post/email reports. Service users must allow for transport and reporting time when ordering tests.
Clinical background:
CEA is a glycoprotein with a molecular weight of approximately 180kDa. It is produced during foetal and embryonic development and repressed after birth.
The half-life is 2 – 8 days but may vary considerably due to molecular heterogeneity of CEA. Longer half-lives are acceptable following chemotherapy; very prolonged half-lives usually indicate a poor response to treatment. Transient increases may occur initially on commencing chemo due to tumour tissue breakdown and release of markers into circulation.
Slight to moderate (rarely >10ng/mL) occur in 20-50% of benign diseases of the intestine, the pancreas, the liver and the lungs. Smokers have significantly higher concentrations than non-smokers.
Specimen container paediatric:
Serum (SST or plain tube)
Specimen container adult:
Serum (SST or plain tube)
Minimum volume paediatric:
0.5 mL
Minimum volume adult:
1 mL blood
Sample stability:
Unseparated: 7 days
Separated:
At 20-25C – 1 day
At 2-8C – 7 days
At -20C – 6 months
Reference ranges:
Adults:
Normal values in non-smokers <4 µg/L.
4 – 10 µg/L – marginal significance
> 10 µg/L- probable malignancy
Other info:
lithium heparin plasma sample also acceptable