CA125

Alternative names, keywords

Samples required

● Clotted blood (gold cap, 5 mL tube).

Test indications

See NICE guidance CG122 Ovarian cancer: the recognition and initial management of ovarian cancer for use in primary care.

Only request in symptomatic patients - NOT suitable as screening test in asymptomatic patients.

Factors affecting test performance/ results

Biotin may interfere - samples should not be taken from patients receiving therapy with high biotin doses (i.e. > 5 mg/day) until at least 8 hours following the last biotin administration.

In rare cases, interference due to extremely high titres of antibodies to analyte-specific antibodies, streptavidin or ruthenium can occur.

Results should always be assessed in conjunction with the patient’s medical history, clinical examination and other findings.

Reference range

up to 35 KU/L
_{Source: 95th percentile limit, Roche Cobas^® CA125 kit insert, 2022-08, V8.0}

CA 125 is not specific for ovarian malignancy and may be increased in many conditions including liver disease, ascites, during menstruation, endometriosis, any peritoneal inflammation, and in other malignancies.

Results within reference range do not exclude malignancy.

Turnaround time

3 days

Enquiries

Biochemistry (Automation)