using the double-blind method , we have studied the diagnostic value of the four ebv antibody titers , vca-iga , vca-igg , ea-iga and ea-igg , in four groups of subjects , each consisting of 50 persons : patients with nasopharyngeal carcinoma ( npc group ) , patients with cancers other than npc in the head and neck regions ( hnc group ) , patients with cancers outside of head and neck regions ( oc group ) and normal individuals ( ns group ) .
C2931822
npc
C0460004
head and neck regions