CA 125 Ovarian Cancer Marker Test (CA 125 Test)

Overview

The CA125 blood test measures the level of Cancer Antigen-125 (CA-125), a protein found in the blood. Elevated CA-125 levels are often associated with CA125 ovarian cancer, but they can also rise in several non-cancerous conditions such as endometriosis, pelvic inflammatory disease, uterine fibroids, liver disease, or even during menstruation.

Because many conditions can affect CA-125 levels, the test is not used alone to diagnose cancer. Instead, it is usually recommended along with ultrasound or CT scans for evaluation. Doctors also rely on CA-125 levels to screen women who are at higher risk, to track treatment progress, and to detect recurrence in those already treated for ovarian cancer.

Why Is the Test Prescribed?

Doctors may recommend the CA125 blood test in the following situations:

• Evaluating symptoms such as bloating, abdominal swelling, pelvic pain, loss of appetite, or frequent urination, which may point to ovarian disease.

• Monitoring women with ovarian cancer, to check whether treatment such as surgery or chemotherapy is effective.
  

• Detecting recurrence in women who have been previously treated for ovarian cancer.

• Screening high-risk women, particularly those with a strong family history of ovarian or breast cancer, or known BRCA1/BRCA2 gene mutations.

• Assessing pelvic masses identified on imaging tests like ultrasound or CT scans.

By combining CA-125 results with imaging and clinical findings, doctors can make more accurate decisions.

Components / Parameters

The CA-125 test measures the concentration of the CA-125 protein in blood, expressed in units per milliliter (U/mL).

• Normal range: Levels below 35 U/mL are usually considered normal.
  

• Elevated levels: High readings may suggest CA 125 ovarian cancer, but can also occur in benign conditions such as cysts or infections.
  

• Trend monitoring: A single test result is less useful than repeated measurements. Watching whether levels rise, fall, or remain stable over time provides better guidance for diagnosis and treatment.

Procedure and Prerequisites

The CA125 blood test is simple and safe:

• A blood sample is collected from a vein in the arm.
  

• No fasting or special preparation is required.
  

• The procedure takes only a few minutes, and results are usually available within one to two days.
  

• Risks are minimal and may include slight bruising or mild discomfort at the needle site.