诱导型一氧化氮合酶在指导晚期鼻咽癌治疗方案选择中的价值

The value of inducible nitric oxide synthase to select the project of treatment in nasopharyngeal carcinoma

背景与目的:同期放化疗被认为是目前治疗晚期鼻咽癌(nasopharyngeal carcinoma,NPC)的最佳方案,但对于同期放化疗对哪一类患者最有效,哪种化疗药物与放疗联合疗效最佳等问题尚没有一致的结论。有学者推荐将顺铂(cisplatin,DDP)同期放化疗方案作为治疗晚期NPC的标准方案。由于顺铂能增加诱导型一氧化氮合成酶(inducible nitric oxide synthase,iNOS)的表达,使杀肿瘤的一氧化氮(NO)合成增加而抗瘤,因此我们考虑是否可以通过检测治疗前NPC组织中的iNOS的表达来对这种同期放化疗的疗效进行预测,并根据预测结果选择相应的治疗方案。本研究旨在探讨NPC肿瘤组织中诱导型iNOS的表达与DDP同期放化疗后鼻咽局部肿瘤全消与残留的关系,以便选择最合适的治疗方案,最大限度地提高鼻咽局部肿块全消率。方法:应用免疫组化法检测DDP同期放化疗后30例鼻咽局部肿块全消和30例鼻咽局部肿块残留的鼻咽部低分化鳞状细胞癌患者在接受治疗前的肿瘤组织中iNOS的蛋白表达情况。结果:iNOS阳性表达定位于NPC细胞的胞质和胞核内,且胞核染色比胞质更强。iNOS在NPC中总的阳性表达率为71.67%(43/60)。在30例肿块全消和30例肿块残留的NPC组织中,iNOS阳性表达率为分别为86.67%、53.33%,差异具有显著性(χ2=6.748,P=0.034)。两组间iNOS弱阳性及中等阳性表达差异无显著性,而强阳性表达全消组低于残留组,差异有显著性(χ2=4.246,P=0.039)。结论:治疗前检测iNOS在NPC组织中的表达,对预测DDP同期放化疗疗效有一定的价值,可根据其表达情况,选择相对合理的同期放化疗方案。

Background and purpose：Concurrent chemo-radiotherapy（CCRT） was considered the best treatment plan for advanced nasopharyngeal carcinoma（NPC）,but there was no uniform conclusion as to which category of patients and which chemotherapy associated radiotherapy would have the best therapeutic effect. As the standard treatment plan for advanced NPC, DDP concurrent chemo-radiotherapy was recommended by some scholars. DDP can raise the expression of inducible nitric oxide synthase（iNOS） protein and synthesize nitric oxide （NO） with anti-tumor effects, so we considered whether the therapeutic effect could be predicted and the corresponding treatment plan could be selectived to detect the iNOS expression in the pretherapy NPC tissues.The purpose of this study was to investigate the relation between the expression of iNOS protein and the nasopharyngeal tumor with complete response or with residue after DDP concurrent chemo-radiotherapy, so that the most appropriate plan of treatment can be adopted and the complete response rate of nasopharyngeal tumor can be raised. Methods：All patients were poorly differentiated NPC.The expression of iNOS protein was examined in 30 patients of nasopharyngeal tumor with complete response and 30 patients with residual tumor after DDP concurrent chemo-radiotherapy by immunohistochemical staining （SP method）.None of the patients had received radiotherapy and chemotherapy.Results：Immunohistochemical examination revealed that iNOS expression in the NPC tissues was located in both the nucleus and cytoplasm of the tumorous tissues. The intensity of iNOS expression was stronger in the nucleus than in the cytoplasm of the tumorous tissues.The positive rates of iNOS protein expressions were 71.67%（43/60） in NPC tissues. It was 86.67% and 53.33% in 30 tumors with complete response and with residual tumor, respectively. The difference was statistically significant.The rate of iNOS strong postive expressions in the group of residual tumors was higher than that of the group with complete response. It was statistically different,but weak and moderate postive expressions did not have statistical difference.Conclusions：According to the difference of iNOS expression, it is a valuable method to select the most appropriate plan of treatment and the complete response rate of nasopharyngeal tumor can be raised.