Human papillomavirus DNA prevalence and type distribution in anal carcinomas worldwide

Abstract

Knowledge about the human papillomaviruses (HPV) types in anal cancers in some world regions is scanty. Here we describe the HPV DNA prevalence and type distribution in a series of invasive anal cancers and anal intraepithelial neoplasias (AIN) grades 2/3 from 24 countries. We analyzed 43 AIN 2/3 cases and 496 anal cancers diagnosed from 1986 to 2011. After histopathological evaluation of formalin-fixed paraffin-embedded samples, HPV DNA detection and genotyping was performed using SPF-10/DEIA/LiPA25 system (version 1). A subset of 116 cancers was further tested for p16INK4a expression, a cellular surrogate marker for HPV-associated transformation. Prevalence ratios were estimated using multivariate Poisson regression with robust variance in cancer dataset. HPV DNA was detected in 88.3% of anal cancers (95%CI:85.1–91.0%) and in 95.4% of AIN 2/3 (95%CI:84.2–99.4%). Among cancers, the highest prevalence was observed in warty-basaloid subtype of squamous cell carcinomas, in younger patients and in North American geographical region. There were no statistically significant differences in prevalence by gender. HPV16 was the most frequent HPV type detected in both cancers (80.7%) and AIN 2/3 lesions (75.4%). HPV18 was the second most common type in invasive cancers (3.6%). p16INK4a overexpression was found in 95% of HPV DNA positive anal cancers. In view of HPV DNA results and high proportion of p16INK4a overexpression, infection by HPV is most likely to be a necessary cause for anal cancers in both men and women. The large contribution of HPV16 reinforces the potential impact of HPV vaccines in the prevention of these lesions.

Immunogenicity and Safety of a 9-Valent HPV Vaccine

“…2,42 The 9vHPV vaccine may also provide increased protection against an extra ∼5% to 10% of vulvar, vaginal, and anal cancers and highgrade vulvar, vaginal, and anal intraepithelial neoplasia. 4,43,44 Prophylactic administration of a 3-dose regimen of 9vHPV vaccine to HPV-naive women aged 16 to 26 years is highly efficacious against vaccine HPV type-related infection and disease. 45 In this report we evaluated whether the 9vHPV vaccine induces noninferior serum antibody responses in boys and girls 9 to 15 years of age (the ideal prophylactic HPV vaccination population) compared with adolescent females/women (ie, young women) 16 to 26 years of age (the population used to establish 9vHPV vaccine efficacy).…”

Prevalence of human papillomavirus infection in squamous cell carcinoma of the anal canal in a Northeast City in Brazil: viral genotyping and clinical aspects

“…Alemany and co-authors [10] found that female patients constituted the majority of the cases of SCC (66.3%). Ouhoummanea and co-authors [8] found that the majority of incidence of anal cancer (60%) was in women.…”

“…Infection with oncogenic, or high-risk, HPV-16 was detected in all cases. Other studies also report that HPV-16 was the main HPV type found in over 80% of carcinomas [10,[16][17][18].…”

“…According to several researches, the peak incidence of anal cancer is between the ages of 58 and 64 years [6][7][8][9][10]. The mean age of patients with anal cancer may had vary among studies, possibly because of the type of population studied and the presence of risk factors such as sexual orientation, immunosuppression (patients with HIV+ infection and transplant recipients), tobacco smoking, and alcoholism [6][7][8][9][10].…”

“…Alemany and coauthors applied a retrospective approach (1986-2011) to evaluate 496 cases of invasive anal cancer for DNA-HPV presence in a multi-center study involving patients from Europe, North America, Latin America, Africa, and Asia. The prevalence of HPV infection for each continent was 87.6, 95.8, 90.4, 61.9, and 81.1%, respectively [10]. In Brazil, Aguiar and coauthors conducted a study of patients with anal carcinomas in Goiânia-Goiás, and found that 76.3% of the samples collected were positive for HPV [9].…”