CA-125

CA-125
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CA-125 (Cancer Antigen 125) is a protein that is often used as a tumor marker in the detection and management of certain types of cancer, particularly ovarian cancer. The protein is encoded by the MUC16 gene.

Structure and Function

CA-125 is a high molecular weight glycoprotein that is part of the mucin family. It is primarily found on the surface of epithelial cells and is involved in cell adhesion and signaling. The protein is most commonly associated with the epithelial ovarian cancer, but it can also be elevated in other conditions, including endometriosis, pelvic inflammatory disease, and pregnancy.

Clinical Use

CA-125 is most commonly used as a biomarker for ovarian cancer. Elevated levels of CA-125 in the blood can indicate the presence of ovarian cancer, although it is not specific to this type of cancer and can be elevated in other conditions. It is often used in conjunction with other diagnostic tests, such as transvaginal ultrasound and CT scans, to improve diagnostic accuracy.

Screening and Diagnosis

While CA-125 is not recommended for routine screening in the general population due to its lack of specificity, it can be useful in women who are at high risk for ovarian cancer, such as those with a family history of the disease or BRCA1 or BRCA2 mutations. In these cases, CA-125 levels can be monitored over time to detect any significant changes that might indicate the development of cancer.

Monitoring and Prognosis

In patients diagnosed with ovarian cancer, CA-125 levels are often measured to monitor the effectiveness of treatment. A decrease in CA-125 levels during treatment typically indicates a positive response, while an increase may suggest disease progression or recurrence. It is also used to monitor for recurrence after treatment has been completed.

Limitations

Despite its usefulness, CA-125 has several limitations. It is not specific to ovarian cancer and can be elevated in a variety of benign and malignant conditions. Additionally, not all ovarian cancers produce CA-125, so a normal CA-125 level does not rule out the presence of cancer. Therefore, it is important to use CA-125 in conjunction with other diagnostic tools and clinical findings.

Related Pages

• Ovarian cancer
• Tumor marker
• MUC16
• BRCA1
• BRCA2
• Transvaginal ultrasound
• CT scan