Positive p16 Immunostaining Is an Independent Prognostic Variable for Disease-free Survival and Overall Survival in Patients With Squamous Cell Carcinoma of the Vulva Treated With Radical Surgery and Inguinofemoral Lymphadenectomy: An Italian Single Center Retrospective Study

Background/Aim: The expression of the cyclin- dependent kinase inhibitor p16 correlates with the presence of human papillomavirus. The purpose of this investigation was to assess the prognostic relevance of p16 expression in patients with vulvar squamous cell carcinoma (VSCC) treated with radical surgery followed by adjuvant (chemo) radiation in selected cases. Patients and Methods: Seventy-eight patients were analyzed retrospectively. Results: Positive p16 immunostaining was detected in 19 (24.4%) patients. Five-year disease-free survival (DFS) and 5-year overall survival (OS) were better in p16-positive compared to p16-negative patients (83.9% versus 37.3% p=0.002 and 91.7% versus 57.6%, p=0.003, respectively). p16 expression retained prognostic relevance at multivariate analysis for both DFS and OS. Conclusion: p16 expression was detected in 24.4% of patients with VSCC and was found to be an independent prognostic variable for both DFS and OS.