Abstract: Objective To investigate the tissues and sera levels of neurensin-2 （NRSN2） in nasopharyngeal carcinoma and their clinical significance.
MethodsFrom June 2014 to December 2016， 84 cases of nasopharyngeal carcinoma tissues and paired adjacent tissues diagnosed and treated in our hospital were collected. Meanwhile， 45 preoperative serum samples and 32 postoperative serum samples were collected and serum samples from 49 healthy subjects were used as controls. Real time fluorescent quantitative PCR （QPCR） was used to detect the levels of NRSN2 in cancer tissues and sera. The difference of NRSN2 levels between cancer tissues and adjacent tissues and the difference of serum levels of NRSN2 before and after operation were compared. The relationship between the NRSN2 levels and clinicopathological features in nasopharyngeal carcinoma was analyzed. The receiver operating characteristic curve （ROC） was used to evaluate the efficacy of tissue NRSN2 levels in the early diagnosis of nasopharyngeal carcinoma. Results NRSN2 level was 11.141±0.801 in 84 cases of nasopharyngeal carcinoma， higher than 1.165±0.071 of the adjacent tissues （P＜0.05）. The serum level of NRSN2 was 9.208±0.841 in 45 cases of nasopharyngeal carcinoma samples， higher than 1.127±0.084 of 49 healthy subjects （P＜0.05）. The serum level of NRSN2 was positively correlated with the tissue level of NRSN2 in patients with nasopharyngeal carcinoma （r=0.445， P=0.002）. The level of NRSN2 was not correlated with sex， age， N stage and neck lymph node metastasis （P＞0.05）， but correlated with T stage， TNM stage and VCA-IgA titer （P＜0.05）. The preoperative serum NRSN2 level of 32 nasopharyngeal carcinoma samples was 10.231±0.979， higher than 6.907±0.713 of postoperative serum samples （P=0.008）. The area under the curve of NRSN2 level was 0.954 （95％CI： 0.891~0.971）. The optimal cut-off value was 3.490 and the sensitivity and specificity of the cutoff value were 95.24％ and 100.0％， respectively. Conclusion In nasopharyngeal carcinoma， the level of NRSN2 was increased， and the serum level of NRSN2 decreased after operation. NRSN2 may participate in the occurrence and development of nasopharyngeal carcinoma. NRSN2 has a certain value in the evaluation and clinical diagnosis of nasopharyngeal carcinoma.