Did You Know... The Facts About HPV?

The Abramson Cancer Center of the University of Pennsylvania
Last Modified: January 13, 2008

  • HPV is one of the most common sexually transmitted diseases in the world.
  • By age 50, about 80% of women have been infected by some type of HPV.
  • Most HPV infections do not cause any symptoms, therefore people are unaware that they are infected.
  • 70-80% of HPV infections resolve spontaneously because our immune system fights them off.
  • HPV is found in 99% of cervical cancers.
  • There are 100 strains of HPV, 12 or more are classified as “high risk” and are linked to cancer.
  • Most women with HPV do NOT develop cervical cancer.
  • About 20% of women infected with HPV will develop chronic infection, and 2% of these will develop cervical cancer.
  • Two strains of HPV are responsible for causing genital warts.
  • Sexual intercourse is not necessary for transmission of HPV; skin to skin genital/genital, genital/anal and possibly genital/oral contact is sufficient for transmission.
  • Use of condoms can reduce the risk of transmission, but it cannot prevent all transmission because some genital tissue remains uncovered.
  • HPV is the cause of many high and moderate grade abnormal pap smears (CIN 2/3) and some low grade lesions (CIN 1).
  • HPV is estimated to cause:
    • 70% of anal cancers
    • 50% of vaginal and vulvar cancers
    • 50% of penile cancers
    • 20% of head and neck cancers
  • Researchers are looking at vaccinating men as well as women.