Abstract
BACKGROUND
Nasopharyngeal carcinoma (NPC) is a common head and neck cancer in Taiwan. The goals of the current study were to investigate whether a nasopharyngeal swab technique could provide enough DNA for polymerase chain reaction (PCR) analysis of the Epstein–Barr virus (EBV)–derived latent membrane protein 1 (LMP‐1) gene and to determine the feasibility and reliability of diagnosing NPC by detection of LMP‐1 in the nasopharynx.
METHODS
320 adults underwent nasopharyngoscopy and nasopharyngeal swab to obtain cells for the LMP‐1 PCR assay; some patients also underwent nasopharyngeal biopsy.
RESULTS
An amount of DNA that was sufficient for PCR was extracted from 96.3% of the swab samples. By detecting LMP‐1 in nasopharyngeal swabs, NPC was diagnosed with a false positive rate of 12.7% (7 of55 patients), a false negative rate of 1.6% (4 of 253 patients), sensitivity of 87.3% (48 of 55 patients), specificity of 98.4% (249 of 253 patients), a positive predictive value of 92.3% (48 of 52 patients), and a negative predictive value of 97.3% (249/256 patients). NPC was diagnosed by nasopharyngoscopy with a false positive rate of 38% (30 of 79 patients), a false negative rate of 0.4% (1 of 241 patients), sensitivity of 62% (49 of 79 patients), specificity of 99.6% (240 of 241 patients), a positive predictive value of 98% (49 of 50 patients), and a negative predictive value of 88.9% (240 of 270 patients). Only 7 (0.2%) of 256 patients with a diagnosis other than NPC had LMP‐1 detected in the nasopharyngeal space.
CONCLUSIONS
Detecting EBV genomic LMP‐1 by nasopharyngeal swab diagnosed NPC with 87.3% sensitivity and 98.4% specificity. EBV genomic DNA usually is not detected by PCR‐based methods in the nasopharyngeal space. Its incidence is estimated to be as low as 0.2% among the general population. The nasopharyngeal swab coupled with PCR‐based EBV LMP‐1 detection could serve as part of a screening program for high‐risk populations. Cancer 2003;97:1909–13. © 2003 American Cancer Society.
DOI 10.1002/cncr.11312