High-risk human papillomavirus genotypes and associated clinical pathological factors among patients with oropharyngeal squamous cell carcinoma in north-western Tanzania

BACKGROUND: Oropharyngeal squamous cell carcinoma (OPSCC) is a significant global health concern, with incidence rising as the prevalence of high-risk human papillomavirus (HPV) increases. Understanding HPV genotypes and their associated clinicopathological factors is essential to improving OPSCC diagnosis and management, particularly in resource-limited settings. This study investigated the prevalence of high-risk HPV genotypes and associated factors in formalin-fixed, paraffin-embedded (FFPE) tissue blocks from patients with OPSCC at Bugando Medical Centre, Tanzania. METHODS: A total of 85 FFPE tissue blocks from histologically confirmed OPSCC cases, collected between July 2023 and January 2025, were analysed. Genomic DNA was extracted, and high-risk HPV genotypes were detected using the Anyplex™ II HPV28 real-time polymerase chain reaction assay. Demographic, behavioural, and clinicopathological data were collected via structured questionnaires and analysed using Stata version 15. RESULTS: The mean age of patients was 55.3 ± 17.6 years (range, 24-92 years), with a slight male predominance (57.6%). Most participants were unaware of HPV's role in the causation of OPSCC, 65/85 (77.3%). HPV DNA was detected in 38/85 (44.7%) of cases, with HPV-16 the most prevalent, 27/85 (31.8%), followed by HPV-33, 8/85 (9.4%), and HPV-18, 7/85 (8.2%). HPV-positive tumours were significantly associated with favourable histopathological features, including a pushing border, less than 50% keratinisation, absence of perineural invasion, and a dense population of tumour-infiltrating lymphocytes (p < 0.001). Additionally, HPV-positive OPSCC was associated with better prognostic indicators, including lower rates of nodal involvement. CONCLUSION: High-risk HPV plays a critical role in OPSCC. HPV-positive tumours are associated with favourable histopathological and prognostic features, supporting the clinical value of routine HPV testing for prognostic stratification and patient management. These findings also underscore the need for greater public awareness, expanded HPV vaccination programmes, and strengthened preventive strategies to reduce the burden of HPV-associated OPSCC.