CA 125

CA 125

Alternate Test Name

Cancer Antigen 125

Ovarian Cancer Marker

Epic Mnemonic
Sunquest Mnemonic

LAB155
CAG125

Category

Chemistry

Methodology

The Roche Cancer Antigen 125 electrochemiluminescent immunoassay is used. Results obtained with different methods or kits cannot be used interchangeably.

Test Performance Schedule

Sunday - Saturday

Result Availability

Within 24 hours

Container

Gold top (SST), Red top (serum), or Green top (lithium heparin) tube

Volume

Pref. Vol.: 1.0 mL serum or plasma
Min. Vol.: 0.5 mL serum or plasma

Collection Instructions

• Routine venipuncture

• Immediately after collection, gently invert tube 5-10 times

• Clot 30 minutes

• Promptly centrifuge 10 minutes

• If no gel barrier is present immediately transfer serum or plasma to a plastic tube and refrigerate

• Properly centrifuged gel barrier tube does not require transfer of serum or plasma to separate tube

Transportation Instructions

Refrigerated

Stability

• Refrigerated: 5 days

Remarks

Medicare Medical Necessity Policy

Biotin, also referred to as Vitamin B7 or Vitamin H, can interfere with this test when taken in mega doses of 5mg (5000 mcg) or more. It is often promoted as a skin and hair beauty aid. Please ask your patients to refrain from taking Biotin or supplements containing Biotin for at least 24 hours before collecting specimens for lab testing.

https://biotinfacts.roche.com/

https://www.fda.gov/medicaldevices/safety/alertsandnotices/ucm586505.htm

CPT Codes

86304

Effective/Revised

7/31/2019

CA 125 belongs to the family of hybridoma-defined tumor markers. CA 125 is found in a high percentage of non-mucinous ovarian tumors of epithelial origin and can be detected in serum. It does not occur on the surface epithelium of normal ovaries (adult and fetal). Ovarian carcinoma accounts for about 20 % of gynecological tumors. CA 125 has been found in the amniotic fluid and in the coelomic epithelium; both of these tissues are of fetal origin. In tissues of adult origin, the presence of CA 125 has been demonstrated in the epithelium of the oviduct, in the endometrium and in the endocervix.

Elevated values are sometimes found in various benign gynecological diseases such as ovarian cysts, ovarian metaplasia, endometriosis, uterus myomatosus or cervicitis. Slight elevations of this marker may also occur in early pregnancy and in various benign diseases (e.g. acute and chronic pancreatitis, benign gastrointestinal diseases, renal insufficiency, autoimmune diseases and others). Markedly elevated levels have been found in benign liver diseases such as cirrhosis and hepatitis. Extreme elevations can occur in any kind of ascites due to malignant and benign diseases.

Although the highest CA 125 values occur in patients suffering from ovarian carcinoma, clearly elevated values are also observed in malignancies of the endometrium, breast, gastrointestinal tract and various other malignancies.

Although CA 125 is a relatively unspecific marker it is today the most important tumor marker for monitoring the therapy and progress of patients with serous ovarian carcinoma. At primary diagnosis the sensitivity of CA 125 depends on the FIGO stage (FIGO = Federation of Gynecology and Obstetrics); higher tumor stages are associated with higher CA 125 levels.