The value of inducible nitric oxide synthase to select the project of treatment in nasopharyngeal carcinoma / 中国癌症杂志

ABSTRACT

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.