Molecular Genotyping of Human Papillomavirus (HPV) in Hypopharyngeal Cancer

Background: In recent years, head and neck cancers have become common worldwide, ranking sixth in incidence. In 2007, in France the incidence increased by 14,697 including 11,158 among men, which places them in fourth place. The same year, 32,268 patients were hospitalized for this pathology, but 95% are associated with alcohol and tobacco poisoning. Few data exist on these cancers in Africa and Senegal. In recent years, many studies have hypothesized that about 25% of head and neck cancers are associated with high-risk oncogenic human papillomaviruses (HPV) whose role in cervical cancer was already widely established. Objective: To know the prevalence and genotypes of HPV in head and neck cancers, particularly hypopharyngeal cancer. Material and method: This study was carried out on samples of biopsies of hypopharynx cancerous tissue (ulcerative-budding lesion) and healthy oropharyngeal tissue obtained from the ENT department of the Fann hospital, then sent to the Molecular Biology Unit of the Ouakam military hospital (HMO). The nucleic acids extraction was carried out using the standard method of the Zymo research kit “Quick-DNATM Miniprep Plus kit” https://www.zymoresearch.com/. Molecular HPV detection and genotyping were performed by multiplex RT-PCR with the Seegene AnyplexTM II HPV28 kit Detection on a Biorad CFX96 automaton according to the manufacturer’s protocol for the simultaneous genotyping of 28 types of HPV including 19 at High Risk (HR) and 9 low risk (LR). Results: 156 patients were sampled, 61 Hypopharynx cancer biopsies and 95 healthy tissues. The median age of the general population was 36.5 years [12, 73]; the median age of the population with hypopharyngeal cancer of 40 years. Of the general study population 24.36% (38/156) was infected with HPV. In populations with hypopharyngeal cancer, HPV prevalence was 19.67% (12/61), 17.84% (5/28) in men and 21.21% (7/33) in women. HPV6 was the most frequently encountered genotype in the cancer population. Multiple infections have also been noted in cancer patients: HPV6+HPV18, HPV6+HPV56. For patients without hypopharyngeal cancer, the HPV prevalence was 27.36% (26/95), 9.59% (7/73) in women and 89.36% (19/22) in men. Several types of HPV-HR genotypes (HPV18, HPV26, HPV69), and HPV-LR genotypes (HPV42, HPV43, HPV70, HPV6) have been detected in healthy patients but also cases of co-infections (HPV6+HPV69; HPV56+HPV44; HPV58+HPV18). Conclusion: Our results showed a higher prevalence of HPV in non-cancer patients compared to hypopharyngeal cancer patients. The genotypes (HPV 6, 18 and 56) were observed in the study population. Molecular genotyping does not show a significant involvement of HPV in hypopharyngeal cancer.