From the Guidelines
There are approximately 100 HPV types that have been identified, with over 40 of these types infecting the genital area. These HPV types are categorized based on their association with cervical cancer, with low-risk types (e.g., types 6 and 11) causing benign or low-grade cervical cell changes, genital warts, and recurrent respiratory papillomatosis, and high-risk types (e.g., types 16,18,31,33,35,39,45,51,52,56,58,59,68,69,73, and 82) acting as carcinogens in the development of cervical cancer and other anogenital cancers 1. Some key points about HPV types include:
- Low-risk HPV types can cause genital warts and low-grade cervical cell abnormalities
- High-risk HPV types can cause high-grade cervical cell abnormalities and anogenital cancers
- High-risk HPV types are detected in 99% of cervical cancers, with types 16 and 18 causing approximately 70% of cervical cancers worldwide 1
- Infection with high-risk HPV types is necessary but not sufficient for the development of cervical cancer, as most women with high-risk HPV infection do not develop cancer 1. The diversity of HPV types highlights the importance of vaccination and regular screening for cervical cancer, as current vaccines like Gardasil 9 protect against nine HPV types responsible for approximately 90% of cervical cancers and genital warts, but do not protect against all HPV types that can cause cancer.
From the Research
HPV Types
- There are more than 100 genotypes of human papillomavirus (HPV) that have been identified, differing in targeted tissue and carcinogenic activity 2.
- According to a 2021 study, with more than 200 types identified, human papillomavirus (HPV) commonly causes infections of the skin and mucosa 3.
- A 2014 study concluded that there was consistent and sufficient epidemiological, experimental and mechanistic evidence of carcinogenicity to humans for 12 HPV types for cervical cancer, and these types were considered as 1A carcinogens 4.
High-Risk HPV Types
- The 12 HPV types considered as 1A carcinogens are: HPV16, HPV18, HPV31, HPV33, HPV35, HPV39, HPV45, HPV51, HPV52, HPV56, HPV58, and HPV59 4.
- A 2023 study analyzed the prevalence of 14 high-risk HPV genotypes in women enrolled in the national program for cervical cancer screening in Lazio Region, Italy, and found that HPV 16 and 31 are the most prevalent genotypes, followed by HPV 68,66,52,58, and 51 5.
HPV-Related Cancers
- HPV infection is the most common sexually transmitted infection in the United States, and some HPV infections can lead to clinical manifestations ranging from benign papillomas or warts to intraepithelial lesions, and in some cases, cancer 3.
- Cervical cancer is by far the most common HPV-related disease, with about 99.7% of cervical cancer cases caused by persistent genital high-risk human papillomavirus (HPV) infection 6.