The CA125 (Cancer Antigen 125) assay uses a monoclonal antibody that is relatively specific for surface antigen derived from a papillary serous cystadenocarcinoma. It is detectable in adult pleura, pericardium and peritoneum. It is used primarily as a marker for cancer of the ovary.
Elevated CA125 levels can also be seen in association with malignancies of breast, cervix, uterus, liver, pancreas, stomach, colorectum and lung.
Non-malignant elevations of CA 125 have been reported for ascites, cirrhosis, hepatitis, pancreatitis, fibroids, endometriosis, ovarian cysts, first trimester pregnancy and pelvic inflammatory disease.
CA125 is best used for patient monitoring. It is of only limited value as a diagnostic aid for intra-abdominal malignancy.
CA125 is a MEIA AxSYM assay. Samples must be serum.
Reference Range =< 35 kU/L
Borderline = 35-65 kU/L