HPV Types Most Commonly Associated with Cervical Cancer
HPV types 16 and 18 are the dominant oncogenic types, causing approximately 70% of all cervical cancers worldwide, with HPV 16 being the single most prevalent type. 1, 2
Primary Oncogenic Types
- HPV 16 is the most common type, accounting for approximately 62% of single-type HPV-positive cervical cancers 3
- HPV 18 is the second most common, representing approximately 18.9% of single-type HPV-positive cervical cancers 3
- Together, HPV 16 and 18 account for at least two-thirds of cervical carcinomas across all continents and are present in 80.9% of HPV-positive cervical cancers 1, 3
Additional High-Risk Types
Beyond the dominant types 16 and 18, several other HPV types contribute to cervical cancer:
- HPV 45 is the third most common oncogenic type, accounting for approximately 5.4% of single-type infections in cervical cancer 3
- Other high-risk types include HPV 31,33,35,39,51,52,56,58,59,68,73, and 82, all classified as carcinogenic based on epidemiologic evidence 4
- Probable high-risk types include HPV 26,53, and 66, though these are less commonly associated with cervical cancer 4
Clinical Significance and Prognosis
- HPV is detected in 99% of all cervical tumors, establishing it as a necessary cause of cervical cancer 1, 2
- Cancers associated with HPV types 16,18, and 45 are diagnosed in women who are on average 10.5 years younger than those with cancers caused by other HPV types, suggesting faster progression to malignancy 3
- HPV 18 DNA presence is specifically associated with poor prognosis in cervical cancer 1
Low-Risk Types (Not Associated with Cancer)
- HPV types 6 and 11 are low-risk types primarily associated with genital warts and laryngeal papillomas, not cervical cancer 1, 5
- These types do not contribute to high-grade dysplasias or invasive cervical cancer 5
Vaccine Implications
- Prophylactic vaccines targeting HPV 16 and 18 have the potential to prevent more than two-thirds of worldwide cervical carcinomas and approximately 80.9% of HPV-positive cervical cancers 1, 3
- Current vaccines show >90% protection against persistent HPV infection with vaccine-targeted types for up to 5 years after vaccination 5
Important Caveats
- Not all HPV infections lead to cancer; approximately 90% of infections are transient and clear within 1-2 years 2
- Persistent infection with high-risk HPV types is necessary for progression to cancer, with the stepwise development from infection to invasive cancer taking approximately 20 years on average 2
- HPV vaccination does not eliminate all cervical cancer risk, as approximately 20-30% of cases are caused by non-vaccine types, making continued cervical screening essential 2, 5