CA 125

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CA 125

Description

Formal name: Cancer Antigen 125

CA-125 is a protein present on some normal tissues and on the surface of cancer cells of various types but specially on ovarian cancer cells. CA-125 levels can also be high in other situations apart from cancer, including menstruation, pregnancy, and pelvic inflammatory disease.

It is normally prescribed before starting therapy for ovarian cancer or if at high risk for developing it, and afterwards during and after treatment in order to monitor evolution with treatment.

Its concentration is measured by means of analysis of a blood sample drawn from the vein in the arm.

Purpose of the test

This test is used to follow women who have a family history of ovarian cancer.

Also CA-125 is used to monitor therapy during treatment for ovarian cancer and to detect whether cancer has come back after treatment.

Before a patient starts treatment for cancer, the physician may order a baseline CA-125 to compare against future analysis. During therapy, physicians monitor response to therapy testing at intervals. CA-125 may also be measured periodically after therapy is completed. When an increase in CA-125 is detected, this may indicate that cancer has returned.

Reference range values

1.9 - 16.3 kU/L

Abnormal findings

CA-125 levels decreased during therapy generally means that the cancer is remitting with treatment.

CA-125 levels increased during therapy generally means that the cancer may not be responding to therapy.

High CA-125 levels after treatment is finished can be indicative that the cancer has returned.