What is the antigen associated with hepatocellular cancer (HCC)?

Alpha-fetoprotein (AFP) is the Antigen Associated with Hepatocellular Carcinoma (HCC)

The antigen associated with hepatocellular carcinoma (HCC) is alpha-fetoprotein (AFP). 1

Role of AFP in HCC

Alpha-fetoprotein is a well-established tumor marker for HCC with the following characteristics:

• AFP is typically elevated in patients with HCC, with levels often exceeding 400 ng/mL in cases of active disease 1, 2
• It serves as both a diagnostic and surveillance marker for HCC in high-risk populations 1
• AFP is included in all major clinical guidelines for HCC management and surveillance protocols 1

Diagnostic Performance of AFP

AFP has variable performance as a diagnostic marker:

• Sensitivity: Approximately 60% at a cutoff of 20 ng/mL 2
• Specificity: Increases significantly at higher cutoffs (>400 ng/mL) 1
• Clinical significance: AFP >400 ng/mL in a patient with cirrhosis and a focal hypervascular liver lesion (>2 cm) is highly suggestive of HCC and can be used for diagnosis without biopsy 1

Limitations of AFP as a Marker

• Only 10-20% of early-stage HCCs present with abnormal AFP levels 1
• Normal AFP levels are found in up to 46% of patients with HCC 2
• Only about 18% of HCC patients have AFP values >400 ng/mL (the level typically considered diagnostic) 2

Clinical Applications of AFP in HCC Management

AFP is used in several aspects of HCC management:

1. Surveillance: Combined with ultrasound for monitoring high-risk patients (those with cirrhosis or chronic hepatitis B/C) 1

2. Diagnosis: Elevated AFP (>400 ng/mL) in combination with characteristic imaging findings can establish diagnosis without biopsy 1

3. Monitoring: Used to track treatment response and detect recurrence 1

4. Prognosis: Higher levels often correlate with more advanced disease and poorer outcomes 1

Other Tumor Markers for HCC

While AFP is the primary antigen associated with HCC, other markers have been investigated:

• Des-gamma-carboxy prothrombin (DCP/PIVKA-II) 1
• AFP-L3 fraction (glycosylated AFP) 1
• Squamous cell carcinoma antigen (SCCA) 3, 4

However, none of these markers have replaced AFP in routine clinical practice for HCC management.

Clinical Pitfalls to Avoid

• Don't rule out HCC based solely on normal AFP levels, as many HCCs do not produce elevated AFP
• Remember that mild AFP elevations (20-200 ng/mL) can occur in benign liver conditions including chronic hepatitis and cirrhosis 2
• AFP levels should always be interpreted in conjunction with imaging findings and clinical context 1
• Avoid unnecessary biopsies in patients with cirrhosis who have characteristic imaging findings and elevated AFP (>400 ng/mL) 1

In summary, alpha-fetoprotein (option B) is the correct answer as the antigen associated with hepatocellular carcinoma. PSA (option A) is associated with prostate cancer, CEA (option C) with colorectal and other gastrointestinal cancers, and CA-125 (option D) with ovarian cancer.