Should I get an Alpha-Fetoprotein (AFP) test?

AFP Testing: Indications and Recommendations

The Alpha-Fetoprotein (AFP) test should only be performed if you fall into specific high-risk categories, as it is not recommended as a general screening test for the broader population.

When AFP Testing is Recommended

Pregnancy Screening

• AFP testing is primarily used during pregnancy as part of maternal serum screening between 16-18 weeks of gestation 1
• It helps detect neural tube defects and can be part of screening for chromosomal abnormalities 2
• This should be voluntary and only undertaken with proper counseling and access to follow-up services 1

Liver Cancer Screening

AFP testing is recommended for individuals at high risk for hepatocellular carcinoma (HCC), including:

• Asian men over 40 years and Asian women over 50 years 1
• Persons with liver cirrhosis 1
• Individuals with a family history of HCC 1
• Africans over 20 years of age 1
• Any carrier of hepatitis B over 40 years with persistent/intermittent ALT elevation and/or high HBV DNA level >2,000 IU/ml 1

Metabolic Disorders

• Patients with certain urea cycle disorders (citrullinemia, ornithine transcarbamylase deficiency, etc.) who haven't had liver transplants may benefit from AFP monitoring 1

Limitations of AFP Testing

1. Low Diagnostic Accuracy: AFP alone has limited sensitivity and specificity as a screening biomarker 1

   • Elevated levels are found in <20% of patients with early-stage HCC 1
   • Normal AFP levels (<20 ng/mL) can be present in up to 46% of HCC patients 1

2. False Positives: AFP can be elevated in:

   • Pregnancy 1
   • Chronic liver diseases (HBV/HCV infection) 1
   • Other cancers (intrahepatic cholangiocarcinoma, colon cancer metastases, lymphoma, germ cell tumors) 1

Recommended Approach

If you're concerned about liver cancer:

• AFP should not be used alone but combined with ultrasound examination every 6-12 months for those at high risk 1
• Imaging findings (CT or MRI) are considered more definitive than AFP levels alone 1

If you're pregnant:

• AFP testing should be part of a comprehensive prenatal screening program with proper counseling 1
• Testing should be performed between 16-18 weeks of gestation 1
• Results require proper interpretation by specialists with access to follow-up services 1

Important Caveats

• A normal AFP level does not rule out cancer, especially early-stage HCC 3
• AFP testing should be performed in conjunction with imaging studies for cancer screening 1
• For pregnant women, AFP screening requires access to comprehensive follow-up services including counseling, ultrasound, and amniocentesis if needed 1
• The decision to undergo AFP testing should be made after proper education about its purpose, limitations, and potential consequences 1