鼻咽癌患者放化疗前后外周血浆EB病毒DNA含量变化

目的比较鼻咽癌（nasopharyngeal carcinoma，NPC）患者放化疗前后血浆EB病毒DNA（EpsteinBarrVirusDNA，EBV-DNA）水平的变化，评价EBV—DNA水平与NPC肿瘤负荷及短期疗效的关系。方法采用实时荧光定量聚合酶链反应测定60例鼻咽癌患者放化疗前后及40例健康对照者外周血浆中的EBV—DNA水平。结果NPC治疗前EBV-DNA阳性率为83．3％，中位拷贝数为8869copy／mL；治疗后阳性率为21．7％，中位拷贝数为0copy／mL；健康对照组阳性率为5．0％，中位拷贝数为0copy／mL。NPC残留组阳性率为81．8％，中位拷贝数为7263copy／mL；消退组阳性率为8．2％，中位拷贝数为0copy／mL。NPC患者治疗前及治疗后组血浆游离EBV—DNA水平及阳性率均高于健康对照组（P〈0．05），治疗前高于治疗后（P〈0．01）。放化疗后，NPC残留组高于消退组（P〈0．01）。结论NPC患者血浆EBV—DNA水平是反映肿瘤负荷的灵敏指标，可作为短期疗效评估的参考。

Change of plasma Epstein-Barr virus DNA in patients with nasopharyngeal carcinoma after radiotherapy and chemotherapy

Objective To compare the levels of the plasma Epstein Barr virus DNA （EBV-DNA） in patients with nasopharyngeal carcinoma（NPC） before and after radiotherapy and chemotherapy and to assess the relationships between the level of EBV-DNA and tumor load and the short-term effect. Methods Plasma EBV-DNA from 60 NPC patients before and after treatment and 40 healthy volunteers was detected with real-time fluorescence quantitative polymerase chain reaction. Results The positive rate and the copies of free plasma EBV-DNA of NPC patients before and after treatment were all higher than those in control （5.0%, median, 0 copy/mL, P 〈 0. 05 ）, while significantly higher in those before treatment（83.3%, median 8 869 copies/mL） than those after treatment（21.7%, median 0 copy/mL, P 〈 0.01 ）. After treatment,the positive rate and copies of plasma EBV-DNA of the residual group （81.8%, median 7 263 copies/mL） were also higher than those of the subsided group（8.2%, median 0 copy/mL, P 〈 0. 01 ）. Conclusions The cell-free plasma EBV DNA level was shown to be proportionately related to the presence of malignant disease. It was a sensitive marker to reflect the tumor burden and the short-term effect.