Which strains of Human Papillomavirus (HPV) are considered particularly high risk?

Human Papillomavirus (HPV) encompasses numerous strains, some of which are classified as high risk due to their association with various forms of cancer, particularly cervical cancer. The strains identified as particularly high risk, specifically 16 and 18, are well-documented for their significant contribution to the development of cervical dysplasia and subsequent cervical cancer.

HPV 16 and 18 together account for a substantial portion of cervical cancer cases worldwide. Their oncogenic properties are attributed to the production of early proteins that can interfere with the normal regulatory pathways of the host cell, promoting uncontrolled cell growth and inhibiting apoptosis, which leads to malignancies.

In contrast, strains like 6 and 11 are generally classified as low risk since they are primarily associated with benign lesions such as genital warts and do not have a strong correlation with cancer development. Other strains, while also high risk, such as 31 and 33, or 45 and 52, are considered high risk but are not as prevalent in association with cervical cancer as strains 16 and 18. Thus, while these other strains can contribute to cancer risk, they do not carry the same weight in significance compared to 16 and 18.