Telomerase assay and nested polymerase chain reaction from nasopharyngeal swabs for early noninvasive detection of nasopharyngeal carcinoma

The main purpose of this study was to analyze sensitivity and specificity o f combining nested polymerase chain reaction for detection of Epstein-Barr virus (EBV) genome and telomerase assay for identifying nasopharyngeal carc inoma (NPC), Eighty patients with NPC and 27 healthy control subjects were included in this study; 97.5% and 94.9% of NPC patients were positive for E BV genome and telomerase activity, respectively. When nasopharyngeal swabs were tested, 95.7% presented the EBV genome and 85.5% were positive for ter omerase expression. The sensitivity for counting either positive result of these two techniques was 100%. Among the 27 control subjects, only 6 and 5 cases were positive for EBV DNA and telomerase activity respectively. This indicated a specificity of 92.6% when both positive results were included. At present, early diagnosis of NPC requires multiple biopsy specimens, espe cially to identify subclinical cases. Because this study showed a very high sensitivity for detecting NPC from swabs when combining the telomerase ass ay and nested polymerase chain reaction technique, this noninvasive techniq ue may be a good candidate for screening of subclinical NPC, especially bef ore multiple biopsy specimens are obtained.