中文摘要：

目的探讨鼻咽癌患者血清EBV-DNA数量与鼻咽癌临床分期的关系，评估EBV-DNA水平在鼻咽癌病情进展中的意义。方法初诊鼻咽癌患者127例，其中Ⅰ期17例，Ⅱ期23例，Ⅲ期45例，Ⅳ期42例。抽取血清样品，应用巢式荧光定量PCR技术检测鼻咽癌患者血清EBV-DNA的拷贝数，分析其数量与鼻咽癌临床分期的相关性。结果本组鼻咽癌患者血清EBV-DNA的检出率为97．6％（124／127），EBV-DNA拷贝数的中位数为8897400copies／μl（0-221667600copies／μl）。Ⅰ、Ⅱ、Ⅲ、Ⅳ期患者DNA拷贝数分别为（4．34±1．04）×10^3，（4．34±0．79）×10^4，（8．77±1．74）×10^5，（8．09±1．74）×10^6，依病情进展而显示了逐步升高的趋势（P〈0．05），呈正相关性（r=0．687，P〈0．05）。结论鼻咽癌患者血清EBV-DNA水平与鼻咽癌患者临床分期呈正相关性，提示EBV-DNA水平与鼻咽癌病情进展密切相关，有助于评估患者预后。

英文摘要：

Objective To investigate the relationship between plasma EBV-DNA copy and clinical staging of of cases with nasopharyngeal carcinoma （NPC） to evaluate the implications of plasma level of EBV-DNA in the development of tumor. Methods By using the procedures of fluorescent quantitative nested-PCR, EBV-DNA copies were detected in 127 plasma samples taken from untreated patients with NPC, with 17 cases at stage Ⅰ, 23 at stage Ⅱ, 45 at stage Ⅲ and 42 at stage Ⅳ. Then, analyzed was the relationship between plasma EBV-DNA copies and clinical stages of NPC patients. Results In this group of plasma samples taken from untreated NPC patients, 124 were determined as positive, with a positive rate of 97.6% and a median level of EBV-DNA being 8 897 400 copies/μl （ranged from 0 to 221 667 600 copies/μl）. The copy numbers of EBV-DNA for different stages of NPC were （4.34±1.04）×10^3,（4.34±0.79）×10^4,（8.77±1.74）×10^5,and（8.09±1.74）×10^6 for stage Ⅰ, Ⅱ,Ⅲand Ⅳ respectively, showing a gradually increased tendency from stage Ito stage Ⅳ （P〈0.05） and a positive correlation of EBV-DNA level with staging level of NPC tumor （r = 0. 687, P〈0.05）. Conclusions EBV-DNA level in plasma is positively correlated with the stage of patients with NPC, suggesting that the level of EBV-DNA level in plasma was closely related with the development of tumor in nasopharynx and that determination of plasma EBV-DNA level should be helpful for evaluation on the prognosis of cases with NPC.