What does the CA125 test mean?

In daily life, many people undergo routine physical examinations at hospitals on a regular basis—regardless of gender. Some individuals may encounter the CA125 test during these check-ups. So, what exactly does the CA125 test mean? Below is an overview.

What does the CA125 test mean?

CA125 is a glycoprotein primarily used to assist in diagnosing gynecological malignancies. Serum CA125 levels are markedly elevated in patients with ovarian cancer and are also higher than normal in those with breast, uterine, cervical, or gastrointestinal cancers. Mild elevations may also occur in some healthy individuals, during early pregnancy, or in benign conditions such as benign ovarian tumors or uterine fibroids. The radioimmunoassay (RIA) positivity cutoff for serum CA125 in healthy individuals is 35 kU/L; approximately 95% of healthy adult women have CA125 levels ≤35 U/mL. Importantly, CA125 is not a specific biomarker for ovarian cancer—elevated levels may also be observed in patients with fallopian tube adenocarcinoma, endometrial cancer, cervical cancer, pancreatic cancer, colorectal cancer, breast cancer, and lung cancer. Whether an elevation holds clinical significance requires comprehensive evaluation in conjunction with clinical findings. Unexplained mild elevations warrant close follow-up with repeat testing—ideally within two weeks—and should be interpreted alongside imaging findings, particularly ovarian morphology.

Additional Information: Clinical Significance of CA125

1. Serum CA125 levels are significantly elevated in ovarian cancer patients. In cases where chemotherapy or surgery proves effective, CA125 levels decline rapidly. Moreover, rising CA125 levels may precede the onset of clinical symptoms upon disease recurrence.

2. CA125 levels may also increase during the first three months of pregnancy.

3. Pelvic and abdominal tuberculosis can cause CA125 levels to rise up to tenfold or more.

The above provides an explanation of what the CA125 test means. CA125 is a glycoprotein mainly used to aid in diagnosing gynecological malignancies. Levels are markedly elevated in ovarian cancer patients and are also higher than normal in patients with breast, uterine, cervical, or gastrointestinal cancers. We hope this information is helpful to you—and wish you good health and happiness!