EXPRESSION CHANGES IN SERUM TPA, EBV AND CYFRA21-1 AND THEIR CLINICAL DIAGNOSTIC VALUE IN PATIENTS WITH NASOPHARYNGEAL CARCINOMA

Pu Wang^*, Jianguo Zhang, Shengbin Zhong, Rongyue Liu, Guangli Chen

The First People's Hospital of Fuyang District, Hangzhou, Zhejiang, 311400, China

Objective: To study expression changes in serum levels of tissue polypeptide antigen (TPA), Epstein-Barr virus (EBV), cytokeratin 19 (CYFRA21-1) and their clinical diagnostic value in patients with nasopharyngeal carcinoma (NPC). 

Methods: 158 patients with NPC admitted to our hospital between January 2016 and January 2017 were analysed retrospectively; 62 patients who were in our hospital during the same period with benign head and neck diseases were also selected. Follow-ups were conducted with NPC patients for 3 years, and patients were divided into groups according to patient prognosis—recurrence or distant metastasis (n=98) versus clinical remission (n=60)-as well as according to patients’ clinical stages—stage Ⅰ (n=23), stage Ⅱ (n=40), stage Ⅲ (n=61), stage IV (n=34). At admission, 5 ml of early morning fasting venous blood was collected from all patients; TPA and CYFRA21-1 levels were detected by enzyme-linked immunosorbent assay, whereas the quantitative real-time fluorescence method was used to detect EBV DNA. The serum levels of TPA, EBV DNA and CYFRA21-1 in each group were compared to analyse the changes in their expression in patients with NPC and thus explore their clinical diagnostic value. 

Results: The positive rates of serum TPA, EBV and CYFRA21-1 in the NPC group were 66.46%, 51.90% and 67.90%, respectively, all of which were significantly higher (P<0.01) than those in the benign disease group. The positive rates of serum TPA, EBV and CYFRA21-1 in the recurrence or distant metastasis group were 98.98%, 79.59% and 96.94%, respectively, all of which were significantly higher (P<0.05 or <0.01) than in the clinical remission group. The positive rate of TPA, EBV and CYFRA21-1 showed an upward trend correlated with the clinical stage. In other words, the positive rate of patients in the stage Ⅳ group was significantly higher than that of stage Ⅰ, Ⅱ and Ⅲ groups, the stage Ⅲ group rate was significantly higher than that of the stage Ⅰ and Ⅱ groups, the stage Ⅱ group rate was significantly higher than that of the stage I group (all differences significant at P<0.01). The sensitivity of TPA in diagnosing NPC patients was 95.45%, the specificity was 51.81%, the positive predictive value was 66.46% and the negative predictive value was 91.94%; the sensitivity of EBV DNA in diagnosing NPC patients was 96.47%, the specificity was 43.70%, the positive predictive value was 51.90% and the negative predictive value was 95.16%. The sensitivity of CYFRA21-1 in diagnosing NPC patients was 99.07%, the specificity was 53.98%, the positive predictive value was 67.09% and the negative predictive value was 98.39%.

Conclusion: Serum TPA, EBV and CYFRA21-1 levels are highly expressed in NPC patients, and these levels varied with the changes of patient's prognosis and clinical stage. Thus, they have particular value in the diagnosis of NPC and can be widely used in clinical practice.