ABSTRACT
<p><b>OBJECTIVE</b>To discuss the diagnostic value and possibility to be a dynamic monitoring index of serum sialic acid (SA) in nasopharyngeal carcinoma (NPC) patients.</p><p><b>METHODS</b>Serum SA and Epstein-Barr virus-viral coat antigens-IgA (EBV-VCA-IgA) were detected in 50 cases of NPC before treatment, after clinical recovery and recurrence. Healthy adult and patients of benign lesions of head and neck were also detected as controls.</p><p><b>RESULTS</b>SA and EBV-VCA-IgA were positively related significantly in different periods of NPC patients. SA was significantly varied dynamically before and after radiation and chemical therapy in NPC patients. The positive rate of SA was 94.0% (47/50) before treatment, 2.0% (1/50) after clinical recovery, 96.2% (25/26) in recurrent patient and 4.2% (1/24) in patients without recurrence. The reaction of EBV-VCA-IgA was slow and its corresponding positive rates were 90.0%, 90.0%, 84.6%, 0% and 75.0% respectively. The sensitivity of SA in pre-treated NPC patients was 94.0%, higher than EBV-VCA-IgA (90.0%). The specificity of serum SA was 93.0% in this series, lower than that of EBV-VCA-IgA (96.0%).</p><p><b>CONCLUSION</b>Dynamic detections of serum SA combined with EBV-VCA-IgA can be used as indices in dictating the changes in NPC patients and screening of high-risk population, judgment of curative effect and prediction of prognosis.</p>