Immunohistochemical Expression of p16 and Its Association with Recurrence in Adult-Onset Recurrent Respiratory...

Recurrent respiratory papillomatosis (RRP) is a rare, benign epithelial tumor primarily caused by low-risk human papillomavirus (HPV) types 6 and 11. Although p16 is widely used as a surrogate marker of high-risk HPV infections in other HPV-related malignancies, its role in RRP remains unclear.

This study aimed to investigate the immunohistochemical expression of p16 in Adult-Onset RRP (AORRP) patients with RRP and evaluate its association with clinical recurrence.

We retrospectively reviewed 64 adult patients primarily with AORRP who underwent surgical treatment for RRP at the Nihon University Hospital between January 2008 and March 2022. p16 expression was assessed using a standardized scoring system based on the staining intensity and proportion of positive cells. The patients were categorized into four groups: negative, low, intermediate, and high expression. Recurrence was defined as the need for additional surgical intervention after the initial treatment. Statistical analyses were performed using the Chi-square test.

p16 positivity (score ≥1) was observed in 51 (51/64:80%) cases. The high expression group (Score 5-6) demonstrated significantly higher recurrence rates than the negative group (P = 0.0036). All the patients in the high-expression group experienced recurrence. However, no significant difference was observed in the recurrence among the other groups.

High p16 expression may serve as a potential prognostic marker for AORRP recurrence. Given the simplicity and accessibility of immunohistochemical staining, p16 scoring may be considered a valuable tool for the risk stratification and long-term disease management of AORRP.