Detection of human papillomavirus and the relationshipbetween p16 positivity with prognostic clinical andhistopathological parameters in laryngeal carcinoma

INTRODUCTION AND PURPOSE: Laryngeal cancer is the sixth most common cancer, accounting for 3% of all cancers. Despite the role of Human Papillomavirus in the etiology of oropharyngeal carcinoma and overexpression of the p16 protein has been shown, there is no adequate study to explain the role of HPV and p16 as biomarkers in laryngeal cancers. In this study, we investigated the presence of HPV and the expression of p16 protein, which is considered as an HPV indicator, in clinical and pathological parameters in laryngeal squamous cell carcinoma. MATERIALS AND METHODS: Histopathological data were evaluated retrospectively in 81 cases of total and partial laryngectomies diagnosed as laryngeal squamous cell carcinoma between 2008-2017 in Sakarya University Medical Faculty Sakarya Training and Research Hospital Pathology Laboratory. HPV DNA was analyzed by RT-PCR in paraffin sections of the tumor tissues and HPV DNA was detected in cases of isolated HPV DNA. Immunohistochemically, p16 protein expression was evaluated statistically by histopathological parameters in all cases. FINDINGS: HPV DNA in two (2.5%) and p16 positivity in 13 (16%) cases were detected in 81 cases studied. HPV type 16 and HPV type 18 were detected in one of the two cases in which HPV DNA was detected. p16 expression was present in one of two cases that detected HPV DNA. p16 positivity was not correlated with age, tumor size, histologic grade, tumor stage, lymph node metastasis, lymphovascular invasion, cartilage invasion, surgical margin positivity, smoking status, chemotherapy/radiotherapy status, HPV, recurrence and mortality (p>0.05). The relationship between HPV and clinicopathologic parameters could not be evaluated statistically because the presence of HPV DNA was limited to two cases. RESULTS: Our study did not show statistically significant results for proving the etiologic and prognostic role of HPV in laryngeal squamous cell carcinoma. Findings in our study do not support the routine use of HPV testing and p16 expression assessment in laryngeal SCC. More extensive work is needed in this regard. Key words: Human Papillomavirus, larynx, p16