HPV16

HPV16 is a type of human papillomavirus and one of the high-risk HPV types most commonly associated with cancer. It is a nonenveloped, circular double-stranded DNA virus in the family Papillomaviridae. Among high-risk types, HPV16 is the most frequently detected in cervical cancers and precancerous lesions and is also a leading cause of other HPV-related cancers, including those of the anus and oropharynx.

Transmission and natural history: HPV16 is transmitted primarily through sexual contact. Infections are often asymptomatic; most clear spontaneously within one to two years. Persistent infection with HPV16 carries a higher risk of progression to precancerous lesions and cancer.

Pathogenesis and cancer risk: The viral oncoproteins E6 and E7 disrupt host tumor suppressor pathways, promoting cell proliferation and genomic instability. Integration of viral DNA into the host genome is commonly observed in cancers and can drive malignant transformation.

Prevention and epidemiology: Vaccination with HPV vaccines (such as Gardasil 9, which includes HPV16, and Cervarix, which targets 16 and 18) prevents infection with HPV16 and reduces cancer risk. Screening with cervical cytology and HPV DNA testing helps detect precancerous changes; vaccination is most effective when given before exposure to the virus. HPV16 is responsible for a substantial fraction of cervical cancers worldwide and is a major contributor to HPV-related oropharyngeal cancers.