Prevalence of human papillomavirus and implication on survival in Chinese penile cancer

We assessed the prevalence of HPV DNA in a large series of Chinese penile cancer and examine its association with the histological subtype, p16^INK4a expression, and prognosis. We pathologically categorized 226 invasive penile squamous cell carcinomas and assessed HPV genotyping by real-time PCR and p16^INK4a immunohistochemistry. The results were correlated with histopathological and clinical parameters and disease-specific survival (DSS). HPV DNA was detected in 32.7% (74/226) of penile cancer cases. The most frequent genotype was HPV 16 (64/74, 86.5%), followed by HPV 18 (6/74, 8.1%). Fifty-nine (26.1%) cases were positive for the p16^INK4a expression, and p16^INK4a expression had a sensitivity of 56.8% (95% CI, 45.2-68.3%) and a specificity of 88.8% (95% CI, 83.8-93.9%) for defining HPV status. HPV DNA (P = 0.019), p16^INK4a (P = 0.038), age (P = 0.018), grade of differentiation (P = 0.001), lymph nodes (P < 0.001), T stage (P < 0.001), M stage (P < 0.001), and lymphovascular invasion (LVI, P = 0.001) were prognostic factors for DSS. HPV-positivity (HR 0.334; 95% CI, 0.158-0.705, P = 0.004) was still a significant prognostic factor for DSS in the multivariate Cox regression model. HPV DNA was observed in one third of Chinese penile carcinoma cases. The p16INK4a expression can indicate high-risk human papillomavirus (HR-HPV). HPV-positive penile tumors confer a survival benefit over HPV-negative tumors.