HPV 16 and 18 Contribution to Cancer Burden
HPV types 16 and 18 together account for approximately 70% of all cervical cancers globally, with HPV-16 alone responsible for 50-60% and HPV-18 for 10-15% of cases. 1, 2
Cervical Cancer Burden by Histologic Type
The contribution of HPV 16 and 18 varies significantly by histologic subtype:
Squamous Cell Carcinoma
- HPV 16 and 18 account for approximately 68% of squamous cell cervical cancers (which comprise 75-80% of all cervical cancers) 3
- HPV-16 alone is responsible for 53-76.7% of squamous cell cases 3, 4
- HPV-18 contributes approximately 7.8-15% of squamous cell cases 3, 4
Adenocarcinoma
- HPV 16 and 18 account for approximately 83% of cervical adenocarcinomas (which comprise 20-25% of all cervical cancers) 3
- In adenocarcinoma specifically, HPV-16 accounts for approximately 40% of cases 2
- HPV-18 is detected in about 30% of adenocarcinoma cases 2
- HPV-18 causes a disproportionately higher percentage of glandular cancers (approximately 32%) compared to squamous cell carcinoma (8%) 1
Other HPV-Associated Cancers
Beyond cervical cancer, HPV 16 and 18 dominate across multiple anatomic sites:
Anogenital Cancers
- HPV 16 and 18 together account for more than 80% of penile, anal, vulvar, and vaginal cancers 2
- Among immunosuppressed individuals, HPV-16 is detected in over 90% of HPV-related vulvar cancers 5, 2
- The distribution of HPV types in vaginal cancers is similar to cervical cancer 5
Oropharyngeal and Head-Neck Cancers
- HPV-16 is present in 70% of HPV-positive oropharyngeal cancers 2
- HPV 16 and 18 account for more than 80% of oropharyngeal cancers in men 2
Global Cancer Burden
- HPV types 16 and 18 are responsible for approximately 70% of all HPV-related cancers worldwide 6, 7, 8, 9
- The remaining 30% of cervical cancers are caused by approximately 10 other high-risk HPV types (including HPV 31,33,35,45,51,52,58, and 59) 5, 2
- HPV infection overall accounts for 5.2% of the worldwide cancer burden 9
Clinical Significance of HPV-16 Dominance
HPV-16 demonstrates unique biological characteristics that explain its predominance:
- HPV-16 has the highest propensity to establish persistent infection compared to other high-risk types 2
- When persistence occurs, HPV-16 shows the greatest probability of progression to CIN 3 2
- HPV-16 is the most frequently identified genotype in high-grade precancerous lesions 2
- Women who test positive for HPV-16 but have negative cytology should be referred immediately for colposcopy 2
Vaccine Impact
- Current HPV vaccines (bivalent, quadrivalent, and nonavalent) all provide protection against HPV 16 and 18 6, 7, 10
- Vaccination targeting HPV 16 and 18 is expected to prevent more than 70% of cervical cancers 6, 10
- The 9-valent vaccine covers 5 additional high-risk types (31,33,45,52,58), which account for an additional 14% of HPV-related cancers in women and 4% in males 6