High-risk type human papillomavirus infection and p16 expression in laryngeal cancer

BACKGROUND: Oropharyngeal cancers associated with high-risk type human papillomavirus (HR-HPV) infection have better prognosis than virus negative cancers. Similarly, the HPV status in laryngeal cancer (LC) may be associated with better outcome. METHODS: Samples from 88 patients with LC were investigated using the polymerase chain reaction (PCR) and p16 immunohistochemistry for HR-HPV analysis. The cut-off point for p16 overexpression was diffuse (≥75%) tumor expression with at least moderate (+ 2/3) staining intensity. RESULTS: The 5-year cumulative survival (CS) rate was 80.7% in all patients with LC. According to a combination of HR-HPV DNA status and p16 overexpression, subjects with LC were divided into four groups: HR-HPV DNA-positive/p16 overexpression-positive (n = 5, 5.7%; CS = 100%), HR-HPV DNA-positive/p16 overexpression-negative (n = 11, 12.5%; CS =81.8%), HR-HPV DNA-negative/p16 overexpression-positive (n = 0), and HR-HPV DNA-negative/p16 overexpression-negative (n = 72, 81.8%; CS = 79.5%). HR-HPV DNA-positive/p16-positive cases tended to have integrated HPV infection and high viral load, compared with HR-HPV DNA-positive/p16 overexpression-negative cases. CONCLUSIONS: LC patients with HPV infection and high levels of p16 expression might have an improved survival outcome; however, it is necessary to recruit additional LC cases with HPV infection to determine the definitive characteristics of HPV-mediated LC and estimate survival outcome. These results may contribute to the development of a useful method for selecting patients with a potentially fair response to treatment and ensure laryngeal preservation.