Human Papillomavirus Leading to Urogenital, Head, and Neck Cancer

Human papillomavirus (HPV) is a group of closely related viruses comprising of more than 200 types and are double-stranded DNA viruses. Several types of HPV cause infections in humans which lead to squamous cell carcinomas and adenocarcinomas. HPV types are categorized into low-risk and high-risk types. Low-risk HPV leads to genital warts and high-risk types causes anogenital, head, and oropharyngeal cancers. High-risk HPV contains HPV types 16 and 18 which are the most pathogenic. HPV has more than 40 genotypes transmitted sexually and are also associated with urinary tract infection that progresses to urogenital cancer. HPV is causatively associated with cervical cancer (100%) and anal cancer (90%) globally. Head and neck cancer, being the sixth most common cancer, is also developed by HPV and it is considered to be involved in 30–60% of oropharyngeal cancer cases as well. The expression of major viral oncoproteins including E6 and E7 dysregulates the cell cycle, degrades the tumor-suppressor P53 and pRb proteins, and promotes cell replication that develops HPV-related malignancies. Downregulating these oncoproteins can be an effective therapy against HPV. Along with radiation therapy and chemotherapy, immunotherapy and vaccines against HPV can provide good measures for controlling cancers, HPV-related cancers.