(1) Background: This study investigated the presence of human papillomavirus (HPV), HPV genotypes, Epstein–Barr virus (EBV), cytomegalovirus (CMV) and herpes simplex virus (HSV) in patients with Head and Neck Cancer (HNC) at both molecular and serological levels. (2) Methods Fifty patients with histopathologically confirmed HNC who were admitted to the Department of Otorhinolaryngology, Istanbul Faculty of Medicine. Viral DNA was detected using quantitative real-time PCR, and serological IgM and IgG antibodies were analyzed using the CMIA method; (3) Results: In blood samples, CMV and HSV DNA were not detected, whereas EBV DNA was identified in 2% and HPV DNA in 4% of patients. In tumor tissues, CMV DNA was detected in 8%, EBV DNA in 10%, and HPV DNA in 6%; HSV DNA is 6%. HPV genotypes 18, 45, and 69 were found in tissue samples. Serologically, IgG positivity for CMV, EBV, and HSV-1 exceeded 90%, whereas IgM positivity was low and not statistically significant; (4) Conclusions: HPV, EBV, and CMV DNA were detected at low frequencies in patients with HNC, while HSV DNA was absent. These findings underline the need for larger multi-center studies and support the consideration of routine viral screening, particularly for HPV, in specific tumor subtypes.

Objective: This study aimed to retrospectively investigate the prevalence of cytomegalovirus (CMV), Epstein-Barr virus (EBV), human papillomavirus (HPV), and herpes simplex virus (HSV) in patients with head and neck cancer, in relation to age, sex, tumor type, and risk factors, at both molecular and serological levels. Materials and Methods: Data from 50 patients diagnosed histopathologically with head and neck cancer who were admitted to the Department of Otorhinolaryngology, Istanbul Faculty of Medicine, between April 2023 and April 2024 were reviewed. At the time of diagnosis, venous blood and tumor biopsy tissue were collected from all cases. CMV, EBV, HPV, and HSV DNA were investigated in both blood and biopsy samples using quantitative real-time PCR. Serologically, IgM and IgG levels were measured using the CMIA method. The data were analyzed along with demographic and clinical parameters. Results: In blood samples, CMV and HSV DNA were not detected, while EBV DNA was found to be positive in 2% and HPV DNA in 4% of the cases. In biopsy tissues, CMV DNA was detected in 8%, EBV DNA in 10%, and HPV DNA in 6% of the samples; HSV DNA was also not detected in tissue samples. HPV DNA positivity showed a statistically significant variation according to tumor type and was more frequently detected in the subtypes of tongue SCC and retromolar SCC (p = 0.005). In serological evaluation, IgG positivity for CMV, EBV, and HSV-1 was above 90%, whereas IgM positivity for all viruses was low and not statistically significant. Conclusion: Among patients with head and neck cancer, the overall positivity rates for HPV, EBV, and CMV DNA were low, and HSV DNA was not detected. The higher prevalence of HPV in specific tumor subtypes suggests a selective role of this virus in head and neck cancers. These findings highlight that the viral etiology of head and neck cancers may vary depending on tumor subtype and individual factors, emphasizing the importance of regional epidemiological data.