p53 and p16ink4a As Predictive and Prognostic Biomarkers for Nodal metastasis and Survival in A Contemporary Cohort of Penile Squamous Cell Carcinoma

Background Human papilloma virus (HPV) infection is implicated in a proportion of invasive squamous cell carcinoma of the penis (PC). A subset of PC involves dysregulation of the p53 pathway. HPV in situ hybridization (ISH) and p16ink4a positivity are surrogate markers for HPV infection, and p53 immunohistochemistry (IHC) denotes abnormality in the p53 pathway. There remains an ambiguity with regard to the contribution of both the pathways in the prognosis of PC. We sought to analyze the clinicopathologic characteristics of a cohort of Indian PC patients with respect to p16 ink4a and p53 expression. Patients and Methods A cohort of 123 PC patients was studied for p16ink4aand p53IHC and HPVISH. The results of these biomarkers were correlated with various clinicopathologic parameters. Results p16ink4a and HPV ISH were positive in 47% and 53% of the tumors, respectively. The proportion of warty, basaloid, or mixed warty-basaloid tumor subtypes showed significant p16ink4apositivity (P Conclusions There is a strong concordance between p16ink4aIHC and HPV ISH results. p16ink4a status is an independent predictor of survival (OS and CSS) in our cohort of PCs. p53 is a predictor of nodal metastasis irrespective of p16 status. Dual positive tumors have a significantly better outcome in comparison to dual negative tumors