There are over 100 different types of human papilloma virus, or HPV. Some types of HPV can cause common skin warts. Approximately 40 sexually-transmitted types of HPV can cause either genital warts, genital cancer or anal cancer, explains the American Cancer Society. Health professionals divide this group into low-risk and high risk types according to their potential for causing cancer. The Centers for Disease Control and Prevention notes that HPV can also cause cancers of the head, throat, tongue and tonsils.
Type 16
Type 16 HPV is the most common of the fourteen or more high-risk HPV types frequently linked with cancers of the cervix, vulva, anus, penis and other parts of the body, notes the CDC. Over 90 percent of all HPV-associated carcinomas of the head and neck involve HPV 16, according to author Michael J. Lace in the Journal of Virology. The CDC notes HPV 16 implication in nearly 50 percent of all cases cervical cancer, the most serious health threat posed by HPV. In 2009 the American Cancer Society estimated that cervical cancer would strike over 11,000 women and take the lives of over 4,000 during the course of the year.
Type 18
Type 18 HPV is another high-risk strain linked to various types of cancer. In most countries type 18 HPV is associated with between 10 and 12 percent of all cases of cervical cancer, according to author Xavier Bosch in a monograph published by the Journal of the National Cancer Institute. More than half of the 500,000 new diagnoses of pre-cancerous changes of the vagina and vulva each year involve HPV 18 and HPV 16, notes the American Cancer Society. These two strains also cause about 80 percent of squamous cell anal cancers.
Type 6
Type 6 HPV is one of the most common causes of genital and anal warts. In the U.S. type 6 and type 11 HPV together cause approximately 90 percent of the 500, 000 new cases of these warts every year, according to the American Cancer Society. Type 6 HPV may cause benign changes to occur in the cervical cells but rarely appears in association with invasive cervical cancer or other invasive cancers.
Type 11
Type 11 HPV, another common low-risk type of HPV, can cause ano-genital warts and warts in the mouth and throat. The CDC points out that, as with HPV type 6, type 11 is hardly ever associated with invasive cancers.
References
- American Cancer Society: Human Papilloma Virus (HPV), Cancer, and HPV Vaccines
- Centers for Disease Control and Prevention: Fact Sheet
- Centers for Disease Control and Prevention: Human Papillomavirus: HPV Information for Clinicians
- "Journal of Virology"; Human Papillomavirus (HPV) Type 18; Michael J. Lace, et al.: November 2009
- Journal of the National Cancer Institute Monographs; Human Papillomavirus and Cervical Cancer; F. Xavier Bosch and Silvia de Sanjosé: June 2003
