TABLE 2.
Decrease in prevalence of keratinizing nasopharyngeal carcinoma, 1956 to 1971 and 1981 to 2012.
| Feature | Group 1, 1981 – March 2012 (n = 63) | Group 2, 1956–1977 (n = 29) | p value |
|---|---|---|---|
| Sex | |||
| Male | 44 | 25 | .09 |
| Female | 19 | 4 | |
| Histology | |||
| Keratinizing | 9 | 10 | .026 |
| Nonkeratinizing | 54 | 19 | |
| In situ hybridization and p16 IHC | |||
| EBV positive | 38 | 15* | |
| HPV/p16 positive | 6 | Not tested | |
| EBV and HPV/p16 negative | 19 | EBV negative – 10 | |
Abbreviations: IHC, immunohistochemistry; EBV, Epstein–Barr virus; HPV, human papillomavirus.
*
Total RNA control revealed inadequate RNA preservation in 1 case. In 3 cases, the tumor was exhausted and absent on section used for EBV–encoded-RNA (EBER) in situ hybridization (ISH).