High AFP
High AFP levels can occur in several malignancies, particularly testicular non seminomatous germ cell tumours, hepatocellular carcinoma (HCC), and hepatoblastoma. AFP can also be elevated in some benign liver diseases and during pregnancy, limiting its specificity. Therefore, a high AFP result supports but does not by itself diagnose malignancy; it is most useful for monitoring staging, progression, or response to treatment.

Low or Normal AFP
A normal or low AFP level does not rule out cancer, as tumour markers lack sensitivity and may remain normal in early stage or even advanced disease. Thus, AFP must be interpreted alongside imaging, clinical findings, and other investigations.