Molecular Epidemiology of Oral Squamous Cell Carcinoma in South East Nigeria: A Case-Control Study

Oral squamous cell carcinoma (OSCC) is the most common oral malignancy in sub-Saharan Africa, yet its molecular epidemiology in the South East Nigerian population remains incompletely characterized. Understanding the interaction between genetic susceptibility, environmental exposures, and tumour biology is essential for improving early detection and targeted treatment strategies. This hospital-based case-control study investigates the epidemiological, histopathological, and selected molecular characteristics of OSCC at the University of Nigeria Teaching Hospital Enugu and Enugu State University Teaching Hospital, over a four-year period. One hundred histologically confirmed OSCC cases were compared with 100 age- and sex-matched hospital controls without oral cancer. Data collected include sociodemographic factors, tobacco and alcohol exposure history, tumor site and staging, tissue p53 immunoexpression levels assessed by immunohistochemistry, and HPV-16 detection by PCR on paraffin-embedded tissue blocks. Results reveal that the lateral tongue and buccal mucosa are the most affected sites, with advanced-stage presentation in 74% of cases. p53 overexpression was detected in 68% of OSCC specimens, and HPV-16 was identified in 22% of tumours. Tobacco chewing and alcohol use were significantly associated with OSCC risk. The findings contribute molecular data to an underrepresented population and have implications for risk stratification, biomarker-guided surveillance, and potential HPV vaccination policy consideration. Keywords: oral squamous cell carcinoma, p53, HPV-16, molecular epidemiology, South East Nigeria.