IGF1 and nasopharyngeal carcinoma: Next, we assessed the potential correlation between serum levels of IGFBP-1, IGF-1 and clinical parameters, including tumour node metastasis (TNM) stage, tumour size, lymphoid nodal states, clinical stage, etc. The level of serum IGFBP-1 significantly correlated with age (P = 0.020), WHO histological classification (P = 0.044) and titre of EA (EBV early antigen-IgA) of NPC (P = 0.015).