Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and is a leading cause of mortality worldwide. While there are many risk factors for HCC including alcohol, obesity, and diabetes, hepatitis B virus (HBV) and hepatitis C virus (HCV) infection still account for the majority of HCC worldwide. Globally, HBV is the leading risk factor for HCC. Patients with chronic hepatitis B (CHB) and advanced liver disease are at high risk for HCC. Screening for HCC is done routinely with ultrasound with or without alpha-fetoprotein (AFP) at six-month intervals. The combination of ultrasound and AFP has been shown to provide some additional detection of 6-8% of cases compared to ultrasound alone; however, this also increases false-positive results. This is because AFP can be elevated not only in the setting of HCC, but also in chronic hepatitis, liver cirrhosis, or ALT flare in CHB, which limits the specificity of AFP. AFP-L3 is a subfraction of AFP that is produced by malignant hepatocytes. The ratio of AFP-L3 to total AFP is reported as a percentage, and over 10% AFP-L3 is consistent with a diagnosis of HCC. Here, we review five cases of patients with CHB, cirrhosis, and HCC, and their levels of AFP and the AFP-L3% at various stages of disease including ALT flare, cirrhosis, initial diagnosis of HCC, and recurrence of HCC. These cases emphasize the utility of AFP-L3% in identifying early, new or recurrent HCC prior to the presence of imaging findings.
Keywords: AFP; AFP-L3; chronic hepatitis B (CHB); hepatitis B virus (HBV); hepatocellular carcinoma (HCC).