Prevalence of human papillomavirus in sinonasal squamous cell carcinoma with and without association of inverted papilloma in Eastern China

Background: Information on HPV-associated sinonasal squamous cell carcinoma (SNSCC) is very limited in China. The aim of this study was to determine the prevalence of HPV in a large cohort of SNSCC patients in China.

Methods: Clinical records and formalin-fixed and paraffin-embedded tumor specimens from 30 SNSCC patients with associated inverted papilloma (IP-SNSCC) and 84 de novo SNSCC (DN-SNSCC) patients were retrieved between 2010 and 2017. HPV status was determined for each specimen using a combination of p16 immunohistochemistry and GP5+/6+ PCR.

Results: Immunohistochemistry for p16 was positive in two IP-SNSCC patients (2/30, 6.7%) and in 16 DN-SNSCC patients (16/84, 19.0%). HPV DNA was detected in six IP-SNSCC patients (6/30, 20%) and in three DN-SNSCC patients (3/84, 3.8%). Expression of p16 was not correlated with the presence of HPV DNA (p = 0.150). Among 18 p16-positive SNSCC patients, only three were HPV DNA-positive. Furthermore, only three of nine HPV DNA-positive tumors exhibited high p16 expression. In IP-SNSCC patients, only one of six HPV DNA-positive tumors exhibited high p16 expression. In DN-SNSCC patients, two of three HPV DNA-positive tumors exhibited high p16 expression. The positive rates for both HPV DNA and p16 in IP-SNSCC patients and DN-SNSCC patients were 3.3 and 2.4%, respectively.

Conclusions: Immunostaining for p16 is not a reliable surrogate marker of HPV status in SNSCC. The presence of HPV is rarely detected in DN-SNSCC patients in Eastern China. IP-SNSCC patients frequently lack of p16 overexpression despite the presence of high-risk HPV DNA.