Role of human papillomavirus infection in the development of oral leukoplakia and oral squamous cell carcinoma

Abstract

BACKGROUND: The annual global oral cancer morbidity is more than 650,000 cases. Between 2007 and 2017 in the Russian Federation, the absolute number of first-ever diagnosed oral cavity malignant neoplasms is constantly increasing. According to many authors, oral squamous cell carcinoma is associated with pre-existing leukoplakia. This disease is the most common and prone to malignant precancerous oral mucosa disease. Human papillomaviruses (HPV) are crucial players in this process. However, the relationship between HPV infection in leukoplakia and oral squamous cell carcinoma remains unclear. AIM: To establish the HPV role in the development of leukoplakia and squamous cell carcinoma of the oral mucosa. MATERIAL AND METHODS: The study included 39 patients with verified various forms of oral leukoplakia and oral squamous cell carcinomas. The squamous cell carcinoma group included 19 patients. The oral leukoplakia group is consisted of 20 patients. The control group of healthy volunteers is represented by 22 patients with clinically healthy oral mucosa. HPV deoxyribonucleic acid (DNA) was detected and quantified in clinical materials by polymerase chain reaction with hybridization-fluorescence detection AmpliSense HPV HRS screen-titer-FL for HPV types 16, 18, 31, 33, 35, 39, 45, 51, 52, 56, 58, 59, 66, and 68 and AmpliSense HPV 6/11-FL for HPV types 6 and 11. RESULTS: HPV types 6 and 11 DNA were isolated in three cases with insignificant clinical disease from 19 samples taken from patients with oral squamous cell carcinoma. In groups of leukoplakia and healthy volunteers, no high oncological risk was identified. Despite a HPV-positive expression in squamous cell carcinoma samples is detected, no significant difference was found between the squamous cell carcinoma group and control group (p=0.09). CONCLUSION: No significant association was noted between HPV and oral squamous cell carcinoma; however, a low carcinogenic-risk HPV was detected in 15.7% of carcinoma samples. No HPV contamination was detected in patients with leukoplakia and healthy groups.