CA 125 (synonym: cancer antigen 125) is a so-called tumor marker. Tumor markers are substances produced naturally in the body by tumors and are detectable in the blood. They can provide an indication of a malignant (malignant) neoplasm and serve as a follow-up examination in the context of cancer aftercare.
The procedure
Material needed
- Blood serum
Preparation of the patient
- Not necessary
Disruptive factors
- None known
Standard values
| Normal value | < 33 U/ml (> 65 U/ml clearly pathological) |
| Women up to 50 years of age | <38 U/ml |
| Women > 50 years of age | <31 U/ml |
Indications
- Patients with suspected ovarian or pancreatic tumors (ovarian and pancreatic tumors).
- Follow-up and therapy control in the above tumors.
Interpretation
Interpretation of increased values
- Ovarian cancer (ovarian cancer; the positive predictive value of indicating invasive ovarian cancer is approximately 40%; the specificity (probability that actually healthy individuals who do not have the disease in question will also be identified as healthy by the test) is 99.9%)
- Pancreatic cancer (pancreatic cancer; detectable in up to 80% of cases).
- Cholangiocarcinoma (bile duct carcinoma)
- Colon carcinoma (colon cancer; detectable in up to 20-40% of cases).
- Gastric carcinoma (stomach cancer; detectable in up to 40% of cases).
- Mammary carcinoma (breast cancer; detectable in up to 10% of cases).
- Cervical carcinoma (cervical cancer; detectable in up to 10% of cases).
- Acute pancreatitis (inflammation of the pancreas; up to 500 U/ml).
- Autoimmune diseases such as collagenoses
- Endometriosis – occurrence of endometrium (uterine lining) extrauterine (outside the uterine cavity).
- Hepatitis (inflammation of the liver)
- Liver cirrhosis – connective tissue remodeling of the liver, which leads to functional limitations.
- Peritonitis (inflammation of the peritoneum)
- Pregnancy (up to 200 U/ml)
Interpretation of lowered values
- No diagnostic significance
Further notes
- Ovarian cancer screening using CA 19-9 with fixed thresholds is not possible! On the one hand, elevated values cannot reliably indicate the disease, and on the other hand, low values cannot reliably exclude a tumor. In one study, it was shown that the rate of change of CA-105 20 concentration can improve the risk calculation.
- When pancreatic cancer (pancreatic cancer) is suspected, CA 19-9 should always be determined as well.