Valproic Acid in the Induction of EBV Lytic Cycle Antigen Expression in Nasopharyngeal Carcinoma

Inclusion Criteria: All subjects must fulfill the following criteria to be eligible for study admission: * Subjects are of age 18 years and above * Biopsy proven nasopharyngeal carcinoma - WHO type 3 * Must have tumor which is accessible to biopsy * For patients with disease localized to the PNS, the lesion must be visualized by endoscopy * Subjects with metastatic disease with disease accessible to biopsy in the PNS if they are deemed by their treating physicians not to require treatment for at least two weeks. * An ECOG performance status of 0-2 * For sexually active women of child-bearing potential, negative pregnancy test within 14 days of enrolling on trial * Must be able to give informed consent Exclusion Criteria: * For patients with localized NPC, PNS lesions that cannot be visualized by endoscopy * Patients with disease inaccessible to biopsy * History of anaphylaxis after exposure to valproic acid * Hepatic dysfunction as defined by total bilirubin 1.0x upper limit of normal. AST (SGOT) and ALT (SGPT) 3x upper limit of normal * Hemoglobin 8g/dl, Absolute neutrophil count 1500 cells/mm, and Platelet count 100,000 /mm * Creatinine 3x upper limit of normal * PT/PTT blood test result not within normal range * Patients who require treatment with an anticonvulsant besides valproic acid during the course of valproate prescribed by the protocol * ECOG Performance status 3-4 * Patients who are pregnant or breast feeding (Sexually active women of childbearing potential must use contraception during course of therapy and within 4 weeks of completion of trial) * Participation in another clinical trial involving therapeutic intervention within 4 weeks of enrollment.