Updating the Natural History of Human Papillomavirus and Anogenital Cancers

Abstract

This chapter addresses the natural history of anogenital human papillomavirus (HPV) infection. Cervical infections are the best understood HPV infection. Cervical HPV persistence is the known necessary event for the development of cervical cancer. New infections appearing at any age are benign unless they persist. Several long-term natural history studies have now shed light on the very low risk of cervical intraepithelial neoplasia (CIN) 3+ in women past the peak of HPV acquisition (e.g., 30 or older) who are HPV-negative or clear their HPV. Although data on transmission of HPV are finally emerging, rates of transmission between heterosexual couples vary widely among studies. Factors that affect the calculations of these rates include a) intervals between testing points, b) rates of concordance or discordance at baseline, and c) difficulty in defining established infections versus contamination. Both cervix to anus and anus to cervix autoinoculation in the same woman appears to be quite common. Whether either site serves as a long-term reservoir is unknown. Studies show that anal infections in women and in men who have sex with men are quite common with cumulative rates up to 70–90%. Similarly, clearance of anal HPV is also common, with few individuals showing persistence unless they are human immunodeficiency virus (HIV)-infected. HIV strongly influences the development of anal intraepithelial neoplasia (AIN). The few studies on the natural history of AIN in HIV-infected men suggest that high-grade AIN is a precursor to invasive anal cancer. Although no natural history studies of AIN are available in women, women with other HPV-associated lesions, including CIN3+ and vulvar cancer, have higher rates of anal cancer. Data on the natural history of HPV of the male genitalia are also emerging, although penile intraepithelial neoplasia is poorly understood. Cumulative rates of HPV are extremely high in men and risks are associated with sexual behavior. Unlike women, prevalence rates are steady across all ages, suggesting that men do not develop protection against reinfection.

Detection of Genital HPV Infection Using Urine Samples: a Population Based Study in India

“…In this context WHO recommendation of screening of women 35 years or above and every five years for three tests in life time will be a more cost effective approach in resource poor settings (Aggarwal, 2014). In our study male condom usage was reported by few couples for spacing of pregnancies and male condoms protect from HPV infections partially (Moscicki et al, 2012). Smokeless tobacco use was found among few women in the form of chewing pan or nasal powder.…”

The Need to Optimize Adolescent Immunization

“…42 High-risk HPV types are responsible for virtually all cases of cervical cancer and a large percentage of anogenital and oropharyngeal cancers in females and males. 43,44 More than 26 000 new cases of HPV-related cancers are diagnosed annually in the United States. With no vaccination among girls 12 years of age and younger, there would be an estimated 168 400 lifetime cases of cervical cancer and 54 100 cervical cancer deaths among this group.…”

Human Papilloma Virus. New Opportunities for Vaccination

“…В то же время ВПЧ высокого онко-генного риска (например, 16,18,31,33,34,35,39,45, 51, 52, 56, 58, 59, 66, 68 и 70-й типы) могут вызывать как высокодифференцированные предраковые пора-жения, так и низкодифференцированные плоскоклеточ-ные интраэпителиальные повреждения (CIN2/CIN3) [6]. Персистирующие инфекции, вызванные онкогенным типами ВПЧ, могут прогрессировать до CIN3 (состояния, непосредственно предшествующего развитию инвазив-ного рака шейки матки) или РШМ, в т. ч. до плоскокле-точной карциномы или аденокарциномы [16][17][18].…”