Immunovirologic assessment of American patients with nasopharyngeal carcinoma and occult primary tumors.

The Epstein-Barr virus (EBV) is closely associated with nasopharyngeal carcinoma, suggesting an etiologic relationship. We have under-taken studies (1) to quantitate the relationship between antibody titers to EBV-associated antigens and nasopharyngeal carcinoma in American patients since most of the patients in previous studies were of either Asian or African descent and (2) to determine the relationship between antibody titers and the clinical course of the disease. Sera from patients with primary or recurrent nasopharyngeal carcinoma and from patients in remission, from patients with various other head and neck tumors (including occult primary lesions and lymphomas), and from normal controls were titrated for IgG antibodies to viral capsid antigen (VCA) and early antigen and IgA antibodies to VCA, using indirect immunofluorescence procedures previously detailed. High titers of antibodies to EBV-induced early antigens and VCA in the IgG fraction and VCA in the IgA fraction were frequently found in the sera of patients with nasopharyngeal carcinoma. A significant reduction in these titers was observed with clinical remission of the disease in treated patients. Preliminary findings suggest that EBV serology may be useful in the evaluation and treatment of patients with nasopharyngeal carcinoma and also in patients with cervical metastases from clinically occult promary sites in order to identify those with occult nasopharyngeal carcinoma.