CA‑125 is a glycoprotein produced by cells lining the ovaries, fallopian tubes, uterus, and peritoneum.

Elevated levels may indicate ovarian cancer, but can also be seen in benign conditions such as endometriosis, menstruation, pelvic inflammatory disease, and pregnancy.

Clinical uses include:

Monitoring treatment response in ovarian cancer patients.

Detecting recurrence of ovarian cancer.

Supporting diagnosis when combined with imaging and other tumor markers.

Not recommended as a screening test for the general population due to lack of specificity.

Analyte: Cancer Antigen 125 (CA‑125) in serum/plasma.

Normal Range (varies by lab): < 35 U/mL.

Abnormal Findings:

Elevated CA‑125: May indicate ovarian cancer, other gynecological cancers, or benign conditions.

Markedly high levels: Often associated with advanced ovarian cancer.

Clinical Use:

Provides a tumor marker for ovarian cancer management.

Helps guide diagnosis, monitoring, and treatment planning.

Supports oncology, gynecology, and internal medicine evaluations.