Pathological and Clinical Analysis of Biomarkers in Head and Neck Squamous Cell Carcinoma (HNSCC): A Diagnostic and Prognostic Study

Background; Head and neck squamous cell carcinoma (HNSCC) exhibit marked biological heterogeneity in behaviour and prognosis. Immunohistochemical (IHC) markers like Ki67, p53, and p16 can offer valuable information regarding the aggressiveness of tumours and may help identify potential targets for therapy. This study aims to assess the immunohistochemical expression of these markers in head and neck squamous cell carcinoma (HNSCC).&quot; and correlate these findings with clinicopathological parameters. Methods; This retrospective observational study included 80 histologically confirmed HNSCC cases from Zagazig University Hospitals (2017–2021). Immunohistochemical staining for Ki67, p53, and p16 was performed on formalin-fixed, paraffin-embedded tumour sections. Biomarker expression was assessed independently by two blinded pathologists and analyzed in relation to clinicopathological parameters. Statistical analyses included Chi-square tests, Kaplan–Meier survival analysis, and Cox regression, with significance set at p < 0.05. Results; Among 80 HNSCC patients (mean age 60.3 years; 83.8% male), the larynx was the most common tumour site. High Ki67 expression, observed in 34% of cases, was significantly associated with poor differentiation, advanced stage, and shortened overall survival. Mutant p53expresion was detected in 55% and correlated with poor differentiation, nodal metastasis, and reduced disease-free survival. p16 positivity (18.8%) was strongly associated with oropharyngeal tumors, early stage, and improved survival outcomes. Multivariate analysis identified high Ki67, mutant p53, and p16 positivity as independent prognostic factors. Conclusion; Ki67 and mutant p53 are associated with aggressive tumour behaviour. p16 expression, though infrequent, suggests a favourable prognosis. Combined biomarker analysis enhances prognostic stratification. Keywords; Ki67; p53; p16; larynx; oropharynx.