CA 72-4 (Carbohydrate Antigen 72-4) – Gastric Cancer Marker

CA 72-4 is a tumor marker primarily used for detecting and monitoring gastric (stomach) cancer. It can also be elevated in other gastrointestinal (GI) and gynecological cancers.

1. Normal Range of CA 72-4

🔹 Levels > 100 U/mL strongly suggest malignancy, especially advanced gastric cancer.

2. Clinical Significance of CA 72-4

🔺 Elevated CA 72-4 Levels

🔹 Best used in combination with other tumor markers:

• Gastric cancer → CA 72-4 + CEA + CA 19-9

• Ovarian cancer → CA 72-4 + CA 125

3. Why is CA 72-4 Measured?

✅ Diagnosing & Monitoring Gastric Cancer
✅ Evaluating Treatment Response → Levels should decrease after successful treatment
✅ Detecting Cancer Recurrence → Rising levels after surgery/chemotherapy indicate relapse
✅ Differentiating Malignant vs. Benign GI Conditions (not a first-line test)

4. Limitations of CA 72-4 Testing

🔹 Not specific to gastric cancer – Can be elevated in other cancers & benign conditions
🔹 Not ideal for early detection – More useful for monitoring progression
🔹 Should be combined with imaging (CT, endoscopy) for diagnosis

Key Takeaways

✅ CA 72-4 is a key tumor marker for gastric cancer, but not highly specific
✅ Best used for monitoring treatment response and recurrence
✅ Levels > 100 U/mL strongly suggest malignancy
✅ Not useful for early cancer screening – Should be used alongside imaging & other markers