Comparative analysis of HPV prevalence and genotype distribution in patients with base of tongue, cervical, and tonsillar squamous cell carcinomas: Indications of a shift in HPV genotype patterns

Problem considered: Human Papillomavirus (HPV) is a significant etiological factor in several cancers, including cervical and head and neck squamous cell carcinoma (HNSCC). While HPV-16 is the most commonly reported genotype globally, emerging evidence indicates regional variations in genotype distribution. In Saudi Arabia, data on HPV genotypes in these cancers remain limited. This study investigated the prevalence and genotype distribution of high-risk HPV (HR-HPV) in base of tongue squamous cell carcinoma (BOTSCC), cervical squamous cell carcinoma (CSCC), and tonsillar squamous cell carcinoma (TSCC), and to evaluate implications for HPV vaccine coverage. Methods: A total of 97 patients (11 BOTSCC, 70 CSCC, and 16 TSCC) were tested for the presence and genotypes of HR-HPV using molecular methods. The distribution of HR-HPV genotypes, single and multiple infections, was assessed, and genotypes were compared to the coverage provided by the nine-valent HPV vaccine. Results: In patients with base of tongue squamous cell carcinoma (BOTSCC), HPV DNA was detected in all cases, with HPV-35 being the most prevalent genotype (90 %), followed by HPV-16 (63 %) and HPV-45 (9 %). Notably, 81.8 % of BOTSCC patients exhibited multiple HPV infections, predominantly dual infections. Among cervical squamous cell carcinoma (CSCC) cases, HPV-35 was again the most frequently detected genotype (84 %), followed by HPV-16 (68 %) and HPV-18 (54 %), while HPV-33 was not observed. In tonsillar squamous cell carcinoma (TSCC), 81.3 % of patients tested positive for. Conclusion: The predominance of HPV-35 over HPV-16 in CSCC and HNSCC highlights a unique regional pattern and a gap in current vaccine coverage. The detection of non-vaccine genotypes supports the need for regional surveillance and potential expansion of vaccine targets to improve protection against HPV-related cancers in Saudi Arabia.