Consultant Urologist The Christie NHS Foundation Trust
Introduction: Penile squamous cell carcinoma (PSCC) is rare and there is a need to refine selection of patients for optimal management. Human papilloma virus infection is a known PSCC risk factor, measured by the histopathological presence of the p16 protein. This study has examined effect of p16 status on overall survival (OS) of PSCC patients managed at a tertiary referral centre. Methods: We analysed retrospective data from a prospectively maintained database for patients with PSCC treated between 2003 and 2022. We excluded patients without reported p16 status. TNM stage was defined by histopathology (AJCC v8) except where fixed inguinal nodes (cN3), pelvic lymphadenopathy (cN3) or distant metastatic disease (M1) were present without histopathological confirmation. The primary outcome was OS (time from definitive primary surgery to death, censored for last follow-up). Multivariate Cox regression analysis for age, p16 status, TNM-stage and grade was performed. Audit approval was obtained. Results: We identified 470 eligible patients. Median follow-up was 28 months (range 0-265). 118 patients (25%) did not undergo invasive lymph node staging (pNX). For the whole cohort, p16+ patients demonstrated 10% greater 5-year OS compared to p16- (71% versus 61%; figure 1). After multivariate analysis (table 1), there remained a significant difference in OS with 40% reduction in the risk of death for p16+ patients compared to p16-. On exploratory analysis by stage, only the N1 group retained this difference, suggesting that this is the group where p16 status may be of most clinical impact. Conclusions: Our data demonstrate that p16+ predicts for improved OS compared to p16- status in PSCC patients. After adjusting for age, stage and grade, this difference was retained in patients with N1 disease, suggesting that p16 status could be further explored as a predictive biomarker in this group. SOURCE OF Funding: None
