| Abstract: | Objective: To examine if the EB virus appears innasopharyngeal epithelial cells in the course oftumorigenesis in nasopharyngeal carcinoma (NPC).Methods: Based on the annual investigation of SihuiCounty, a cancer-prevention base of Sun Yat-senUniversity of Medical Sciences(SUMS) and armorHospital out-patient clinic, more than 450 paraffinembedded NPC tissue specimells, precancerous lesionsand precancerosis from a high--risk population werecollected for detection of an EBV-DNase gene fragmentby an optimized PCR method. Results: In 145 of the149 (97.3%) cases with invasive NPC, and 2 of 4 caseswith in situ NPC, only 2 of the 155 subjects withprecancerosis was DNase gene positive, and all 47 casesexamined in the out-patient department of the TumorHospital with precancerous lesions in the nasopharynxwere negative. Conclusion: The universal presence ofan EBV-DNase gene in NPC tissues and the paucity ofEBV-DNase gene in nonmalignant and precancerouslesions in the nasopharynx in a high-risk populationimply that carcinogenesis of NPC occurs before theappearance of EBV in the nasopharynx. |
