Overview: Cancer Antigen 125 TestIntroduction: The Cancer Antigen 125 Test measures CA 125, a cancer marker to monitor ovarian cancer, which may cause pelvic pain, bloating, or fatigue. Aligned with 2023 NCCN guidelines, it uses an immunoassay for high sensitivity, aiding in cancer screening. This test is critical for guiding diagnosis, treatment monitoring, and improving outcomes in immunology for patients with suspected ovarian cancer.
Other Names: CA 125 Assay, Ovarian Cancer Marker Test.
FDA Status: Laboratory-developed test (LDT), meeting immunology standards for diagnostic accuracy.
Historical Milestone: CA 125 testing began in the 1980s with ovarian cancer research. Immunoassays emerged in the 1990s, and by the 2000s, high-sensitivity assays improved monitoring accuracy.
Purpose: Monitors ovarian cancer, guides treatment, and assesses disease progression in patients with pelvic pain, bloating, or fatigue.
Test Parameters: 1. CA 125
Pretest Condition: No fasting required. Collect serum at any time. Report symptoms like pelvic pain or bloating, and list medications like chemotherapy.
Specimen: 2-5 mL serum (SST). Centrifuge within 1 hour. Transport in a biohazard bag within 8 hours.
Sample Stability at Room Temperature: 8 hours
Sample Stability at Refrigeration: 7 days
Sample Stability at Frozen: 6 months
Medical History: Document pelvic pain, bloating, or family history of ovarian cancer. Include current medications, especially chemotherapy or targeted therapies.
Consent: Written consent required, detailing the tests purpose, diagnostic implications, and potential need for cancer treatment.
Procedural Considerations: Uses an immunoassay to measure CA 125 levels. Results are available in 1-2 days, enabling rapid clinical decisions.
Factors Affecting Result Accuracy: Benign conditions like endometriosis may elevate CA 125 levels. Hemolysis or improper storage can degrade samples.
Clinical Significance: Elevated CA 125 levels indicate ovarian cancer progression, prompting chemotherapy or surgery. Normal levels suggest stable disease or remission.
Specialist Consultation: Consult an oncologist for result interpretation. A gynecologist referral is advised for ovarian cancer cases.
Additional Supporting Tests: Pelvic ultrasound, CT scan, or HE4 test to confirm ovarian cancer or assess disease extent.
Test Limitations: False positives may occur with benign conditions. Results require clinical correlation with imaging.
References: NCCN Ovarian Cancer Guidelines, 2023; Journal of Clinical Oncology, Bast RC, 2022.
