Abstract

Undifferentiated (World Health Organization (WHO) 3) type of nasopharyngeal cancer (NPC) is strongly correlated with Epstein-barr (EBV) virus latent infection. Post-treatment viral reactivation is associated with relapsed or recurrence of NPC. Viral activation can be measured indirectly via plasma IgA responses towards EBV proteins such as EBNA1 and VCA-p18. This study aims at determining the prognostic value of IgA/[EBNA1+VCA-p18] on progression free survival and overall survival of NPC patients. NPC patients aged > 18 years, with locally advanced disease receiving concurrent chemoradiation, with weekly cisplatin 40 mg/m² samples for blood plasma before treatment, 3 months post-treatment, and at 12 months after treatment completion or at the time of disease progression, whichever came first. An established enzyme linked immunosorbent assay (ELISA) method was used for evaluation of IgA/[EBNA1+VCA-p18] level reported as optical density 450 nm (OD₄₅₀) values. Forty six NPC patients, with male predominance and mostly in productive age were included. Twenty seven patients had disease progression or died during study follow up. Mean of pre-treatment IgA OD₄₅₀ was higher in patients with progression compared to those still in remission (2.33 ± 1.08 versus 1.66 ± 1.19, p < 0.05). The higher risk serology group (OD₄₅₀  ≥ 1.4) had shorter time to progression (RR 6.06; p = 0.014; median time to progression is  13.47 month). Overall survival was not influenced by plasma IgA. Pretreatment IgA/[EBNA-1+VCA-p18] may predict early progression for NPC

Key words: Nasopharyngeal cancer, prognosis factor, immunological response, IgA/(EBNA1+ VCA-p18).