Human papillomavirus as a cause of cervical cancer

Human papillomavirusDid you know that every 2 minutes in the world 1 woman dies of cervical cancer?

Human papillomavirus (HPV) is the most common sexually transmitted infection. More than 40 genotypes of HPV can infect the genitals of men and women, including the penile skin, vulva (area outside the vagina), anus, vagina, cervix, and rectal mucosa. The mucosa of the mouth and throat may also be affected.

HPV is divided into high, medium, and low-risk subtypes:

  • Medium and high-risk group (19 genotypes): 16, 18, 26, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 69, 73, 82
  • Low-risk group (18 genotypes): 6, 11, 40, 42, 43, 44, 54, 61, 62, 67, 70, 71, 72, 74, 81, 83, 84, 91

HPV subtypes are divided into two groups: non-oncogenic and oncogenic.

Non-oncogenic subtypes cause skin and genital warts. Some cervical, vulvar, vaginal, penile, anus, head, and neck cancers are associated with oncogenic subtypes (particularly oropharyngeal cancer, which affects the back of the throat, the base of the tongue, and the tonsils).

How can HPV infection cause cancer?

The human papillomavirus (HPV) often occurs in young, sexually active women under the age of 25. The average duration of HPV infection is 4-20 months. Virus elimination (exit from the body, cure) occurs in 90% of those infected with HPV within two years, immune system is main trigger in the elimination process. In the remaining 10%, the infection persists and causes precancerous lesions, which manifest as by intraepithelial squamous cell lesions. Persistent reinfection with high-risk HPV genotypes and an inadequate immune response are essential preconditions for the development of cervical cancer and precancerous cervical lesions. HPV subtypes 16 and 18 are associated with 70% of cervical cancers.

It takes 15 to 20 years for cervical cancer to develop after infection with the papillomavirus, and for women with weakened immune system this period is reduced to 5-10 years.

The American Cancer Society recommends that women ages 30 to 65 get an HPV test, along with a Pap test, every 5 years. According to the recommendation of the National Screening Center of Georgia, for sexually active women aged 25 to 60, screening and a Pap test are recommended at 3-year intervals.