Prevalence of and risk factors for anal human papillomavirus infection in heterosexual men

Global burden of HPV-attributable squamous cell carcinoma of the anus in 2020, according to sex and HIV status: A worldwide analysis

Squamous cell carcinoma of the anus (SCCA) is caused by HPV, and is elevated in persons living with HIV (PLWHIV). We aimed to estimate sex- and HIV-stratified SCCA burden at a country, regional and global level. Using anal cancer incidence estimates from 185 countries available through GLOBOCAN 2020, and region/country-specific proportions of SCCA vs non-SCCA from the Cancer Incidence in Five Continents (CI5) Volume XI database, we estimated country- and sex-specific SCCA incidence. Proportions of SCCA diagnosed in PLWHIV, and attributable to HIV, were calculated using estimates of HIV prevalence (UNAIDS 2019) and relative risk applied to SCCA incidence. Of 30 416 SCCA estimated globally in 2020, two-thirds occurred in women (19 792) and one-third among men (10 624). Fifty-three percent of male SCCA and 65% of female SCCA occurred in countries with a very high Human Development Index (HDI). Twenty-one percent of the global male SCCA burden occurred in PLWHIV (n = 2203), largely concentrated in North America, Europe and Africa. While, only 3% of global female SCCA burden (n = 561) occurred in PLWHIV, mainly in Africa. The global age-standardized incidence rate of HIV-negative SCCA was higher in women (0.55 cases per 100 000) than men (0.28), whereas HIV-positive SCCA was higher in men (0.07) than women (0.02). HIV prevalence reached >40% in 22 countries for male SCCA and in 10 countries for female SCCA, mostly in Africa. Understanding global SCCA burden by HIV status can inform SCCA prevention programs (through HPV vaccination, screening and HIV control) and help raise awareness to combat the disease.

Molecular diagnostics of infectious disease: Detection and characterization of microbial agents in cytology samples

BACKGROUND

Cytology samples are widely used to diagnose various infectious diseases by detection and identification of causative infectious agents, including bacteria, fungi, and viruses. The role of cytopathology in infectious disease has expanded tremendously in the past decades with the advances in molecular techniques. Molecular diagnostic methods, compared to conventional methods, have shown improved patient outcome, reduction in cost, and shortened hospital stay times. The aim of this article is to review molecular testing in cytology samples for diagnosis of infectious diseases.

METHODS

The literature search for molecular testing in common cytology samples for diagnosis of infectious diseases was performed. The findings of the studies were summarized. The common cytology samples included in this article were gynecologic specimens, cerebrospinal fluid, bronchoalveolar lavage, and urine samples.

CONCLUSIONS

There are a number of molecular diagnostic tests that are available to be used in common cytology samples to detect infectious agents. Each test has its own advantages and limitations. It is our hope that upon reading this review article, the readers will have better understanding of molecular diagnostic testing of infectious diseases utilizing commonly sampled cytology specimens in daily practice.

Type-specific concurrent anogenital HPV detection among young women and MSM attending Dutch sexual health clinics

OBJECTIVES

This study aimed to investigate type-specific concurrent anogenital human papillomavirus (HPV) detection and examine associations with concurrent detection.

METHODS

Data from a Dutch repeated cross-sectional study among young sexual health clinic visitors (Papillomavirus Surveillance among STI clinic Youngsters in the Netherlands) between 2009 and 2019 were used. Cohen's kappa was used to assess the degree of type-specific concordance of HPV detection between anal and genital sites for 25 HPV genotypes for women and men who have sex with men (MSM) separately. Associations with type-specific concurrent HPV were identified. Receptive anal intercourse (RAI) was forced into the model to investigate its influence.

RESULTS

Among women (n=1492), type-specific concurrent anogenital detection was common; kappa was above 0.4 for 20 genotypes. Among MSM (n=614), kappa was <0.4 for all genotypes. The only significant association with type-specific concurrent anogenital detection among women was genital chlamydia (adjusted OR 1.5, 95% CI 1.1 to 2.2). RAI was not associated.

CONCLUSIONS

Type-specific concurrent anogenital HPV detection was common among young women, and uncommon among MSM. For women, concurrent HPV detection was associated with genital chlamydia. Our results are suggestive of autoinoculation of HPV among women.

Human papillomavirus-associated anal squamous intraepithelial lesions in men who have sex with men and transgender women living with and without HIV in Karachi Pakistan: implications for screening and prevention

BACKGROUND

Anal squamous intraepithelial lesions (ASIL), strongly related to human papilloma virus (HPV) infection, is more prevalent among men who have sex with men (MSM). However, no such data are available for Pakistan yet, and neither HPV vaccination nor anal-cytology screening is implemented in Pakistan. The purpose of this first ever study was to assess the prevalence of HPV-related anal cytological abnormalities among MSM and transgender women living with and without HIV infection in Pakistan.

METHODS

We conducted a cross-sectional study from March 2016 to November 2017 at sexual health centers run by the Perwaaz Trust and the National AIDS Control Program in Karachi. The study enrolled MSM and transgender women aged greater-than-and-equal-to-18-years who reported anal sex in the preceding 6 months. We collected two anal samples for liquid-based cytology and HPV type testing by PCR, and socio-demographic and behavioral data were collected through face-to face interviews. ASIL and its associations with biological and behavioral risk factors were analyzed through Cox regression for prevalence ratios (PR) and corresponding 95% confidence intervals (CIs).

RESULTS

Out of 271 qualifying participants, 79% were MSM and 21% transgender women. The mean age was 28.8 (± 8) years. Almost 35% (93/271) of the study population had ASIL detected, ASIL was significantly more common among participants living with HIV than in HIV negative ((50/118) 42.4%; vs. (43/153) 28.1%) (p ≤ 0.001). Among ASIL, 66% (61/93) had low-grade squamous intraepithelial lesions (LSIL), and 3.6% (3/93) had high-grade squamous intraepithelial lesions (HSIL). The overall, HPV16 positivity was 35.5% (33/93) among all abnormal anal lesions and all 3 HSIL were HPV16 positive, however, HPV16 positivity could show its association with ASIL detection in univariate model only (PR_crude: 2.11(1.39-3.18)). Moreover, any HR-HPV type (PR 3.04; 95% CI 1.75-5.26), concurrent sexually transmitted infection (STI) (2.13; (1.28-3.55)) and HIV + /HPV + coinfection (1.75; (1.07-2.88)) remained independently associated with ASIL in the multivariate model.

CONCLUSIONS

Abnormal anal cytology among MSM and transgender is prevalent enough to consider optimal screening regimens. Further studies are required to see if periodic anal cytology can be made part of HIV care and treatment programs among MSM in Pakistan.

Epidemiology and Burden of Human Papillomavirus and Related Diseases, Molecular Pathogenesis, and Vaccine Evaluation

Diagnosed in more than 90% of cervical cancers, the fourth deadliest cancer in women, human papillomavirus (HPV) is currently the most common pathogen responsible for female cancers. Moreover, HPV infection is associated with many other diseases, including cutaneous and anogenital warts, and genital and upper aerodigestive tract cancers. The incidence and prevalence of these pathologies vary considerably depending on factors including HPV genotype, regional conditions, the study population, and the anatomical site sampled. Recently, features of the cervicovaginal microbiota are found to be associated with the incidence of HPV-related diseases, presenting a novel approach to identify high-risk women through both blood and cervical samples. Overall, the HPV repartition data show that HPV infection and related diseases are more prevalent in developing countries. Moreover, the available (2-, 4-, and 9-valent) vaccines based on virus-like particles, despite their proven effectiveness and safety, present some limitations in terms of system development cost, transport cold chain, and oncogenic HPV variants. In addition, vaccination programs face some challenges, leading to a considerable burden of HPV infection and related diseases. Therefore, even though the new (9-valent) vaccine seems promising, next-generation vaccines as well as awareness programs associated with HPV vaccination and budget reinforcements for immunization are needed.

Intra-anal use of imiquimod: what is the clinical evidence?

Imiquimod has been demonstrated to be rather effective in patients with anal as well as perianal high-grade squamous intraepithelial lesions (HSILs). Nevertheless, until now the intra-anal use of imiquimod has been considered off-label. The aim of this study is to review the clinical evidence related to the intra-anal use of imiquimod in the treatment of human papillomavirus-related anal lesions. A systematic search in PubMed and Scopus was performed. In total, 422 patients were included. The most common referred comorbidity was HIV infection (281 patients, 66.6%). The principal clinical entities, which were treated with intra-anal imiquimod, were HSILs. The most frequent formulation was self-applied imiquimod cream. In the HSIL group, there was complete healing in 74 patients (35%) and partial in 44 patients (20.9%), while in the wart group, there was complete healing in 128 patients (67%). Recurrence of HSIL was present in 19 patients (15%), while in cases with warts recurrence was present in 38 patients (19.8%). The most common adverse events were pain, itching, and burning sensation. In conclusion, the adverse effects associated with the intra-anal use of imiquimod seem to be minor. The present clinical evidence suggests that imiquimod may be proposed as effective, safe, and relatively well tolerated treatment.

Natural history of human papillomavirus and vaccinations in men: A literature review

BACKGROUND AND AIMS

Infection with high-risk (HR) genotypes of the human papillomavirus (HPV) is necessary for and causative of almost all cervical cancers and their precursor condition, cervical intraepithelial neoplasia. These conditions have been sharply reduced by cervical cytology screening, and a further decrease is expected because of the recent introduction of prophylactic HPV vaccinations. While significant attention has been given to gynecologic HPV disease, men can be affected by HPV-related cancers of the anus, penis, and oropharynx. This literature review aims to address disparities in HPV-related disease in men, and certain HR male subpopulations, compared with women.

DISCUSSION

Overall, immunocompetent men are far less likely than women to develop anogenital HPV-related cancers, despite harboring HR HPV infections at anogenital sites. On the other hand, men who have sex with men and men living with human immunodeficiency virus infection are at considerably higher risk of HPV-related disease. Historic rates of prophylactic HPV vaccination in males have trailed those of females due to numerous multilevel factors, although, in recent years, this sex gap in vaccination coverage has been closing. In the absence of routine HPV screening in males, therapeutic vaccinations have emerged as a potential treatment modality for preinvasive neoplasia and are in various phases of clinical testing.

CONCLUSION

Successful reductions in HPV disease morbidity at the population level must acknowledge and target HPV infections in men.

The association between body mass index and anal canal human papillomavirus prevalence and persistence: the HIM study

Background: While receptive anal sex is an established risk factor for anal human papillomavirus (HPV) infection and squamous cell carcinoma of the anus (SCCA), people with anal HPV infection and SCCA commonly report no lifetime receptive anal sex suggesting other factors may also increase risk for anal HPV infection and persistence. Given potential associations between obesity and conditions that may cause perianal or anal canal lesions, we hypothesized that body mass index (BMI) was associated with HPV infection. Methods: Genotyping for 36 HPV types was conducted on anal canal specimens from men, ages 18-70, from Brazil, Mexico, and the USA. Eligibility included no history of genital warts or HIV. Evaluable specimens were collected from 328 men having sex with men (MSM) and 1348 men having sex with women (MSW) who reported no lifetime receptive anal sex. Prevalence of anal HPV infection and six-month persistence by BMI were estimated in addition to adjusted prevalence ratios for the association between BMI and HPV infection. Results: Among MSW, obese men had a higher prevalence of HPV-16 in the anal canal (3.1%), compared to normal weight men (1.3%) although 95% CI overlapped. Among MSM, prevalence of HPV decreased with increasing BMI. A similar pattern was observed for persistence. After adjustment for confounders, obese MSW had 2.4 times higher odds of HPV-16 compared to normal weight men. Conclusions: BMI may be positively associated with anal HPV (especially HPV-16) among MSW and negatively associated with anal HPV among MSM which supports continued universal HPV vaccination programs.

Merkel Cell Polyomavirus Is Associated with Anal Infections in Men Who Have Sex with Men

Background: Viral infections of the anal/rectal tract of men who have sex with men (MSM) have been poorly studied. Methods: In total, 158 swab samples (81 anal/rectal, 65 throat/oral and 12 urethral) were collected from 126 MSM. DNA was isolated and subjected to real-time PCR assays for the detection of the sexually transmitted (ST) pathogens Chlamydia trachomatis, Neisseria gonorrhoeae and Mycoplasmas ssp, human papillomavirus (HPV) and six human polyomaviruses (HPyVs; JCPyV, BKPyV, Merkel cell PyV–MCPyV-, HPyV-6, HPyV-7 and HPyV-9). Results: C. trachomatis (31/126, 24.6%) and M. genitalium (30/126, 23.8%) were the most frequently detected ST pathogens. Thirty-one/126 (24.6%) patients were positive for at least one HPyV. The significantly (p < 0.05) prevalent HPyV in the anal tract was MCPyV, which was amplified in 27/81 (33.3%) samples, followed by HPyV-6, which was amplified in 6/81 (7.4%) swabs. Coinfections with MCPyV and C. trachomatis or Mycoplasmas were found in 4/21 (19.0%) and 5/21 (23.8%) anal/rectal swabs, respectively. Three/4 MCPyV-C. trachomatis coinfected patients were symptomatic. Conclusions: Based on the high prevalence of MCPyV in the anal/rectal swabs from MSM patients and on the well-known oncogenic properties of MCPyV, sexual transmission and possible involvement of HPyVs in the pathogenesis of diseases of the anal canal should be further studied.

Vaccinations for Anal Squamous Cancer: Current and Emerging Therapies

Human papillomavirus (HPV) infection is responsible for 4.3% of the global cancer burden. Since 2006, current HPV vaccines have reduced the prevalence of the virus in adolescent girls, reduced the prevalence of genital warts, and been proven to reduce the progression of anal intraepithelial neoplasia in men. Herein, we review the epidemiology, virology, and immunology behind the prophylactic HPV vaccines and current recommendations for its use. We also review future immune therapies being trialed for use against HPV-related cancers including anal cancer.

Anal cytology, histopathology and anoscopy in an anal dysplasia screening program: is anal cytology enough?

BACKGROUND AND AIM

The human papilloma virus is the leading cause of anal squamous cell carcinoma. Cytological screening may reduce the associated morbidity and mortality. The aim of the study was to estimate the agreement between anal cytological examination, histopathology and anoscopic visual impression.

METHODS

A prospective study of patients who underwent anal dysplasia screening between 2011 and 2015, in a proctology clinic of a tertiary referral center.

RESULTS

During the study period, 141 patients (91% men, 87% with HIV infection) underwent 175 anal cytology tests. Of these, 33% were negative for intraepithelial lesions or malignancy (NILM), 22% were atypical squamous cells of uncertain significance (ASCUS), 33% were low-grade squamous intraepithelial lesion (LSIL) and 12% were high-grade squamous intraepithelial lesion (HSIL). With regard to anoscopic visual impression, 46% of patients had no lesions and excision/biopsy of the identified lesions was performed in the remaining patients. The weighted kappa-agreement between abnormal cytological results and anoscopic visual impression was moderate (k = 0.48). The weighted kappa-agreement between simultaneous anal cytological examinations and anal histopathologic findings was low (kappa = 0.20). With regard to the histological examination of cases with HSIL or superficially invasive squamous cell carcinoma, 64% of patients had dysplasia of a lower grade according to the cytological analysis (6 ASCUS, 18 LSIL and 4 NILM).

CONCLUSION

There was a poor correlation between anal cytology, histopathology and anoscopic visual impression and a high number of histological studies of HGD that were of a lower dysplastic degree according to the cytological examination. Therefore, anal cytology screening should not be used as the sole method of anal dysplasia screening.

Synchronous anal canal carcinoma in a heterosexual couple

Background

Sexually transmitted Human Papilloma Virus (HPV) infection is a known risk factor for cancer of the anal canal in both men and women.

Case presentation

We describe a report of synchronous carcinoma of the anal canal in a heterosexual couple. High risk type 16 HPV DNA was detected in both tumors.

Conclusion

Longstanding sexual partners may share risk of HPV-associated anal canal cancer.

Acceptability of HPV vaccines and associations with perceptions related to HPV and HPV vaccines among male baccalaureate students in Hong Kong

Objectives

The highly infectious human papillomavirus (HPV) causes both genital warts and cervical cancer in women. In 2009, the prevalence of genital warts in Hong Kong was 203.7 per 100,000 person-years. Cervical cancer, more seriously, was the eight most common cancer among women and girls in Hong Kong, accounting for 2.3% of all new cancer cases in females in 2014. Cervical cancer is a significant global public health problem and HPV is a major risk factor leading to the development of cervical cancer. HPV is also the most common sexually transmitted disease among university students. This is the first study to examine the acceptability of HPV vaccines and associations with perceptions related to HPV and HPV vaccines among the male baccalaureate student population locally.

Methods

A self-administrative cross-sectional survey was used to assess whether male baccalaureate students from eight local Hong Kong universities intended to be immunized for HPV. The study also asked questions concerning how its subjects perceived HPV and HPV vaccines using the Health Belief Model. Data collection spanned from June to September 2015. A multiple stepwise regression model was used to examine associations between cognitive factors and subjects’ intention to take up the HPV vaccine.

Results

A total of 1,004 (83.7%) students aged 18 and 26 participated in this study. 23.3% found vaccinating for HPV acceptable, a level correlating with a number of indicators. Subjects were more likely to find vaccinating acceptable if 1) they knew something about HPV vaccines; 2) they understood that men were susceptible to infection by HPV; 3) they realised they could benefit by HPV vaccination, and 4) they were aware of the arguments for and against HPV vaccination, as disseminated by either the media or peers.

Conclusions

HPV remains a significant public health concern in Hong Kong and China more broadly. This study’s findings show a disconnect between the perceived and actual risk of being infected with the HPV vaccine among male baccalaureate students. This disconnect may be bridged by informing young men of the benefits of their being vaccinated against HPV, by removing the psychological and financial barriers that prevent them from taking up the vaccine and by improving how primary healthcare providers motivate them to get immunized.

Determinants of the presence of human papillomaviruses in the anal canal of Russian men

Knowledge of determinants of anal human papillomavirus (HPV) infections among men is still limited as most of the studies are focused on high-risk populations and geographically narrowed. Such knowledge obtained in different populations is essential for better understanding of HPV natural history, transmission dynamics, and its role in the development and prevention of anogenital malignancies in different regions. Here we tested anal canal swab samples from 359 Russian heterosexual (323 human immunodeficiency virus [HIV]-negative and 27 HIV-positive, aged 18-67 years) men attending a sexually transmitted infection clinic 36 HPV types using a proficient Luminex assay. HPV-positivity in anal samples was common for 332 HIV-negative heterosexual men for overall HPV (15.7%, n = 52), oncogenic HPV (9.6%, n = 32), nononcogenic HPV (8.1%, n = 27), and multiple HPV infections (4.5%, n = 14). The most common anal HPV types were HPV16 (5.7%), HPV45, and HPV51 (1.8% each), HPV66, and HPV87 (1.8% each). No association was found with the number of lifetime sexual partners, age of participants at the time of the study, or their sexual debut. Although anal HPV positivity was more common among HIV-positive men, the current study provides additional evidence that anal HPV can be frequently detected in heterosexual HIV-negative men favoring further studies on transmission routes to discriminate between contamination and true HPV infection.

Comparison of anal HPV natural history among men by country of residence: Brazil, Mexico, and the United States

OBJECTIVES

Globally, anal cancer incidence is rare, but is increasing in some world regions. Our objective was to assess differences in anal HPV natural history in three countries.

METHODS

Men aged 18-70 years were recruited from the US (n = 634), Mexico (n = 665), and Brazil (n = 731). Anal specimens were collected every six-months. HPV genotyping was assessed by Linear Array. Anal HPV prevalence was compared using the Fisher's exact test. HPV infection incidence rates (IR) and 95% confidence intervals (CI) were calculated.

RESULTS

Any anal HPV prevalence was highest among men from Brazil (24%) compared to Mexico (15%) and the US (15%). When stratified by sexual history, the prevalence of any HPV among MSM/MSMW was 43%, 37%, and 45% and 9%, 12%, and 10% for MSW from Brazil, Mexico, and US, respectively. Any HPV incidence was significantly higher among men from Brazil compared to US men (IRR = 2.4, 95% CI = 1.7-3.4) and comparable between men from Mexico and the US (IRR = 1.2, 95% CI = 0.8-1.8).

CONCLUSION

Men in Brazil and Mexico often have similar, if not higher incidence of anal HPV compared to men from the U.S., and may benefit from gender neutral HPV vaccine policies.

Prevalence of human papillomavirus infection of the anal canal in women: A prospective analysis of high-risk populations

Infection with certain types of human papillomavirus (HPV) has been associated with the development of cervical and anal cancer. Worldwide, the incidence of anal cancer has increased markedly. The present study aimed to evaluate the prevalence of HPV infection of the uterine cervix and anal canal in human immunodeficiency virus (HIV)- and non-HIV-infected risk populations. Cervical and anal HPV swabs and cytology samples were collected from 287 patients at the University Hospital of Munich, Germany between 2011 and 2013. Patients were divided into HIV-negative controls (G1) and two risk groups, including HIV-negative patients with cytological abnormalities of the cervix (G2) and HIV-infected patients (G3). Data, including clinical parameters, were analysed. The risk groups had significantly more positive results for HPV in the anus (71.03 and 83.15% for G2 and G3, respectively), as compared with G1. The predominant HPV genotypes found in the anus were high-risk HPV genotypes, which were significantly correlated with concomittant cervical HPV findings. In the risk groups, a significant association between the cytological findings and HPV detection in the cervix was found, while the results of the anus revealed no significance. The results of the present study suggested that the prevalence of HPV infection in the anal canal of risk populations is high. Furthermore, patients with abnormal cervical cytology results and HIV-infected women, irrespective of their individual cervical findings, may have a risk of concomittant anal high-risk HPV infection. Based on the predominant HPV genotypes found in the study, HPV vaccination could reduce the incidence of anal cancer. Nevertheless, high-risk patients should be intensively screened for anal squamous intraepithelial abnormalities to avoid invasive cancer stages.

Human papillomavirus and gastrointestinal cancer: A review

Human papillomavirus (HPV) is one of the most common sexually transmitted infections worldwide. Exposure to HPV is very common, and an estimated 65%-100% of sexually active adults are exposed to HPV in their lifetime. The majority of HPV infections are asymptomatic, but there is a 10% chance that individuals will develop a persistent infection and have an increased risk of developing a carcinoma. The International Agency for Research on Cancer has found that the following cancer sites have a strong causal relationship with HPV: cervix uteri, penis, vulva, vagina, anus and oropharynx, including the base of the tongue and the tonsils. However, studies of the aetiological role of HPV in colorectal and esophageal malignancies have conflicting results. The aim of this review was to organize recent evidence and issues about the association between HPV infection and gastrointestinal tumours with a focus on esophageal, colorectal and anal cancers. The ultimate goal was to highlight possible implications for prognosis and prevention.

Sequential Acquisition of Anal Human Papillomavirus (HPV) Infection Following Genital Infection Among Men Who Have Sex With Women: The HPV Infection in Men (HIM) Study

BACKGROUND

The purpose of this study was to assess the risk of sequential acquisition of anal human papillomavirus (HPV) infection following a type-specific genital HPV infection for the 9-valent vaccine HPV types and investigate factors associated with sequential infection among men who have sex with women (MSW).

METHODS

Genital and anal specimens were available for 1348 MSW participants, and HPV genotypes were detected using the Roche Linear Array assay. Sequential risk of anal HPV infection was assessed using hazard ratios (HRs) among men with prior genital infection, compared with men with no prior genital infection, in individual HPV type and grouped HPV analyses.

RESULTS

In individual analyses, men with prior HPV 16 genital infections had a significantly higher risk of subsequent anal HPV 16 infections (HR, 4.63; 95% confidence interval [CI], 1.41-15.23). In grouped analyses, a significantly higher risk of sequential type-specific anal HPV infections was observed for any of the 9 types (adjusted HR, 2.80; 95% CI, 1.32-5.99), high-risk types (adjusted HR, 2.65; 95% CI, 1.26, 5.55), and low-risk types (adjusted HR, 5.89; 95% CI, 1.29, 27.01).

CONCLUSIONS

MSW with prior genital HPV infections had a higher risk of a subsequent type-specific anal infection. The higher risk was not explained by sexual intercourse with female partners. Autoinoculation is a possible mechanism for the observed association.

Human Papillomavirus Laboratory Testing: the Changing Paradigm

High-risk human papillomaviruses (HPVs) cause essentially all cervical cancers, most anal and oropharyngeal cancers, and some vaginal, vulvar, and penile cancers. Improved understanding of the pathogenesis of infection and the availability of newer tests are changing the approach to screening and diagnosis. Molecular tests to detect DNA from the most common high-risk HPVs are FDA approved for use in conjunction with cytology in cervical cancer screening programs. More-specific tests that detect RNA from high-risk HPV types are now also available. The use of molecular tests as the primary screening tests is being adopted in some areas. Genotyping to identify HPV16 and -18 has a recommended role in triaging patients for colposcopy who are high-risk HPV positive but have normal cytology. There are currently no recommended screening methods for anal, vulvar, vaginal, penile, or oropharyngeal HPV infections. HPV testing has limited utility in patients at high risk for anal cancer, but p16 immunohistochemistry is recommended to clarify lesions in tissue biopsy specimens that show moderate dysplasia or precancer mimics. HPV testing is recommended for oropharyngeal squamous cell tumors as a prognostic indicator. Ongoing research will help to improve the content of future guidelines for screening and diagnostic testing.

Distribution of genital human papillomavirus genotypes in benign clinical manifestations among men from Northern Spain

Background

In the literature, data on the prevalence of human papillomavirus (HPV) infection in men vary significantly and the exact distribution of specific genotypes is still unclear. As infections usually occur without symptoms, men might only attend their hospital clinic when they have a specific concern, being in most cases genital warts (condylomas), which are often caused by low-risk HPV genotypes. The aim of this study was to assess HPV genotype distribution and prevalence among men attending hospital for HPV-associated conditions and to evaluate infection-associated factors.

Methods

Samples from men with clinical manifestations of HPV-related infections seen during 2007–2012 at the Clinical Microbiology and Infectious Control Department at Basurto University Hospital were genotyped using Linear Array HPV Genotyping Test kit (Roche Molecular Diagnostics, Germany). Data on probable risk factors were collected and investigated for possible association.

Results

Of 184 anogenital samples, 138 (75 %) were tested as positive for HPV; 57 (41.3 %) single HPV infections and 81 (58.7 %) multiple infections. Only 45.6 % of HPV-positive samples presented low-risk genotypes 6 or 11, whereas 71/138 (51.4 %) had at least one oncogenic (high-risk) genotype. Oncogenic genotypes and multiple HPV infections were both associated with a higher number of lifetime sexual partners and their incidence appeared to increase with patient age.

Conclusions

Although it is accepted that HPV 6 and 11 genotypes are main causes of condylomas, our findings show a high incidence of multiple infections and high-risk genotypes in men with benign HPV manifestations. The fact that the condyloma is a skin lesion facilitates the entry of virus into cells and thus cancer progression; therefore, monitoring for HPV is important, especially in those patients with high-risk genotypes (regardless of whether they cause condyloma).

Prevalence of Anal Dysplasia in Patients With Inflammatory Bowel Disease

BACKGROUND & AIMS

Although the prevalence of anal dysplasia is higher in some immunosuppressed populations, the prevalence in patients with inflammatory bowel disease (IBD) is unknown. We examined the prevalence of abnormal anal cytology among IBD patients, and its relation to the human papilloma virus (HPV).

METHODS

Adults with IBD and age-matched healthy controls (HC) were recruited. IBD patients were categorized as nonimmunosuppressed (IBD-N) or immunosuppressed (IBD-I). Anal Papanicolaou tests were performed for HPV testing and classification by a cytopathologist as follows: negative, atypical squamous cells of undetermined significance (ASC-US), low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, cancer, or unsatisfactory.

RESULTS

A total of 270 subjects (100 IBD-I, 94 IBD-N, and 76 HC) were recruited. ASC-US were detected in 19 subjects, with a trend toward a higher prevalence among IBD subjects compared with HC (8.8% vs 2.6%; P = .10). The prevalence did not differ with respect to immunosuppression. Crohn's disease (CD) subjects had a higher prevalence of ASC-US compared with others with IBD (P = .02). Among those with CD, female sex and disease duration longer than 10 years were risk factors. There were no cases of low-grade squamous intraepithelial lesion, high-grade squamous intraepithelial lesion, or anal cancer in the cohort. HPV was present in 5.3% and 1.5% of subjects with and without ASC-US, respectively (P = .26).

CONCLUSIONS

Although there was a trend toward abnormal anal Papanicolaou tests in IBD subjects compared with HC, there was no difference based on immunosuppression. The presence of HPV did not correlate with abnormal anal cytology. Risk factors associated with this increased trend include female CD subjects and those with a longer duration of CD. ClinicalTrials.gov number: NCT01860963; https://clinicaltrials.gov/ct2/show/NCT01860963.

Alpha, beta and gamma Human Papillomaviruses in the anal canal of HIV-infected and uninfected men who have sex with men

OBJECTIVES

Anal infection by cutaneous Human Papillomaviruses (HPV) has been rarely investigated. We aimed to assess the prevalence, genotype diversity, and determinants of mucosal (alpha) and cutaneous (beta and gamma) anal HPV infection in men who have sex with men (MSM).

METHODS

Anal samples were collected with a Dacron swab. Alpha HPVs were detected using the Linear Array HPV genotyping test, while beta and gamma HPVs using a PCR combined with Luminex technology.

RESULTS

A total of 609 MSM (437 HIV-uninfected and 172 HIV-infected, most of which were undergoing cART) were enrolled. Alpha, beta, and gamma HPVs were detected in 78.0%, 27.6% and 29.3% of the participants. Only alpha HPV prevalence was significantly higher among HIV-infected compared to uninfected MSM (93.0% vs. 72.1%, p < 0.0001). Beta2 and gamma10 represented the most frequent cutaneous HPV species, with no significant differences between HIV-infected and uninfected individuals. The most common alpha, beta, and gamma genotypes were HPV16, HPV111, HPV121, respectively. Alpha HPV infection was significantly associated with lifetime number of partners, receptive anal sex, and HIV status. Beta and/or gamma HPV infection showed no significant association with HIV status, socio-demographic or sexual behavioral factors.

CONCLUSIONS

A wide spectrum of mucosal and cutaneous HPV types is present in the anal canal. Only mucosal HPV prevalence increased significantly in cases of concomitant HIV infection.

EUROGIN 2014 roadmap: differences in human papillomavirus infection natural history, transmission and human papillomavirus-related cancer incidence by gender and anatomic site of infection

Human papillomaviruses (HPVs) cause cancer at multiple anatomic sites in men and women, including cervical, oropharyngeal, anal, vulvar and vaginal cancers in women and oropharyngeal, anal and penile cancers in men. In this EUROGIN 2014 roadmap, differences in HPV-related cancer and infection burden by gender and anatomic site are reviewed. The proportion of cancers attributable to HPV varies by anatomic site, with nearly 100% of cervical, 88% of anal and <50% of lower genital tract and oropharyngeal cancers attributable to HPV, depending on world region and prevalence of tobacco use. Often, mirroring cancer incidence rates, HPV prevalence and infection natural history varies by gender and anatomic site of infection. Oral HPV infection is rare and significantly differs by gender; yet, HPV-related cancer incidence at this site is several-fold higher than at either the anal canal or the penile epithelium. HPV seroprevalence is significantly higher among women compared to men, likely explaining the differences in age-specific HPV prevalence and incidence patterns observed by gender. Correspondingly, among heterosexual partners, HPV transmission appears higher from women to men. More research is needed to characterize HPV natural history at each anatomic site where HPV causes cancer in men and women, information that is critical to inform the basic science of HPV natural history and the development of future infection and cancer prevention efforts.

HPV and anal cancer in HIV-infected individuals: a review

HIV infection is one of the strongest risk factors for anal squamous cell cancer (ASCC). Most ASCC are caused by HPV, and most HPV-associated ASCC are caused by HPV-16. Anal HPV infections are very common in men who have sex with men (MSM), and nearly universal among HIV-infected MSM. High-grade anal intraepithelial neoplasia (HGAIN), the precursor for ASCC, is present in about 30 % of HIV+ MSM, but neither the progression rate to ASCC nor the regression rate are known. The incidence rate of ASCC among HIV-infected people has risen in the first decade after cART became available, but appears to be plateauing recently. Anal cytology has poor sensitivity and specificity. High resolution anoscopy (HRA) is advocated by some as a screening tool in high-risk groups, but is cumbersome and time-consuming and it is unknown whether HRA followed by treatment of HGAIN prevents ASCC. More research is needed on progression and regression rates of HGAIN, on effective therapy of HGAIN, and on biomarkers that predict HGAIN or anal cancer. HPV vaccination and earlier start of cART may prevent most anal cancers in the long run.

Diversity of human papillomavirus in the anal canal of men: the HIM Study

Human papillomavirus (HPV) infections are associated with the development of anogenital lesions in men. There are no reports describing the distribution of non-α HPV types in the anal canal of a sexually diverse group of men. The HPV Infection in Men (HIM) Study is a multicentre study on the natural history of HPV infection in Brazil, Mexico, and the USA. At baseline, 12% of anal canal PCR HPV-positive specimens were not typed by the Roche Linear Array, and were considered to be unclassified. Our goals were to characterize HPVs among these unclassified specimens at baseline, and to assess associations with participant socio-demographic and behavioural characteristics. Unclassified HPVs were typed by sequencing of amplified PGMY09/11 products or cloning of PGMY/GP + nested amplicons followed by sequencing. Further analysis was conducted with FAP primers. Of men with unclassified HPV in the anal canal, most (89.1%) were men who have sex with women. Readable sequences were produced for 62.8% of unclassified specimens, of which 75.2% were characterized HPV types. Eighteen, 26 and three different α-HPV, β-HPV and γ-HPV types were detected, respectively. α-HPVs were more commonly detected among young men (18-30 years) than among older men (45-70 years), whereas β-HPVs were more frequent among mid-adult men (31-44 years). β-HPVs were more common among heterosexual men (85.0%) than among non-heterosexual men. All β-HPVs detected among non-heterosexual men were β2-HPV types. The high prevalence of β-HPV in the anal canal of men who do not report receptive anal sex is suggestive of other forms of transmission that do not involve penile-anal intercourse.

Multiple human papillomavirus infections are highly prevalent in the anal canal of human immunodeficiency virus-positive men who have sex with men

Background

Anal cancer has become one of the most common non-AIDS-defined tumors among Human Immunodeficiency Virus-positive (HIV+) individuals, and a rise in its incidence among HIV+ Men who have Sex with Men (MSM) has been shown, despite the introduction of Highly Active Anti-Retroviral Therapy (HAART). Human Papillomavirus (HPV) infections are highly prevalent among HIV+ MSM and recent studies have shown high rates of HPV-associated anal intraepithelial neoplasia (AIN) and anal cancer among this population.

Methods

In the present study we determined the prevalence and nature of HPV co-infections in the anal canal of 324 HIV+ MSM attending a high specialty medical center in Mexico City, DNA extraction and amplification with generic primers for HPV was performed, followed by detection of specific types and co-infections with INNO-Lipa, and identification of variants by amplification and sequencing of the E6 and LCR region of HPV 16.

Results

We found a very high prevalence of HPV infections among this cohort (86%), with more than one fourth of them (28%) positive for type 16. Among HPV16-positive patients, European variants were the most prevalent, followed by Asian-American ones. Among these individuals (HPV-16+), we identified co-infections with other 21 HPV types namely; 11, 51, 52, 6, 66, 68, 74, 18, 45, 35, 26, 44, 70, 53, 54, 82, 31, 33, 56, 58, 59.

Conclusions

HIV+ MSM show a very high rate of HPV infections in the anal canal and those with type 16 exhibited a multiplicity of associated types. This study emphasizes the need for an early detection of HPV infections among HIV+ MSM in order to establish its utility to prevent anal neoplasia and cancer.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0671-4) contains supplementary material, which is available to authorized users.

Human papilloma virus and squamous cell carcinoma of the anus

The incidence of anal cancer is increasing. In the UK, the incidence is estimated at approximately 1.5 per 100,000. Most of this increase is attributed to certain at-risk populations. Persons who are human immunodeficiency virus (HIV)-positive and men who have sex with men (MSM), Organ transplant recipients, women with a history of cervical cancer, human papilloma virus (HPV), or cervical intraepithelial neoplasia (CIN) are known to have a greater risk for anal cancer. This paper will focus on HPV as a risk factor for anal intraepithelial neoplasia (AIN) and discusses the etiology, anatomy, pathogenesis, management of squamous cell carcinoma (SCC) of the anus.

Early adoption of the human papillomavirus vaccine among Hispanic adolescent males in the United States

BACKGROUND

Human papillomavirus (HPV) infection is common among Hispanic males, but to the authors' knowledge little is known regarding HPV vaccination in this population. The authors examined the early adoption of the HPV vaccine among a national sample of Hispanic adolescent males.

METHODS

The authors analyzed provider-verified HPV vaccination data from the 2010 through 2012 National Immunization Survey-Teen (NIS-Teen) for Hispanic males aged 13 years to 17 years (n = 4238). Weighted logistic regression identified correlates of HPV vaccine initiation (receipt of ≥ 1 doses).

RESULTS

HPV vaccine initiation was 17.1% overall, increasing from 2.8% in 2010 to 31.7% in 2012 (P < .0001). Initiation was higher among sons whose parents had received a provider recommendation to vaccinate compared with those whose parents had not (53.3% vs 9.0%; odds ratio, 8.77 [95% confidence interval, 6.05-12.70]). Initiation was also higher among sons who had visited a health care provider within the previous year (odds ratio, 2.42; 95% confidence interval, 1.39-4.23). Among parents with unvaccinated sons, Spanish-speaking parents reported much higher intent to vaccinate compared with English-speaking parents (means: 3.52 vs 2.54; P < .0001). Spanish-speaking parents were more likely to indicate lack of knowledge (32.9% vs 19.9%) and not having received a provider recommendation (32.2% vs 17.7%) as the main reasons for not intending to vaccinate (both P < .05).

CONCLUSIONS

HPV vaccination among Hispanic adolescent males has increased substantially in recent years. Ensuring health care visits and provider recommendation will be key for continuing this trend. Preferred language may also be important for increasing HPV vaccination and addressing potential barriers to vaccination.

Factors affecting the prevalence of strongly and weakly carcinogenic and lower-risk human papillomaviruses in anal specimens in a cohort of men who have sex with men (MSM)

Background

MSM are at higher risk for invasive anal cancer. Twelve human papillomaviruses (HPVs) cause cervical cancer in women (Group 1 high-risk HPVs (hrHPVs)) and 13 HPVs are probable/possible causes (Group 2 hrHPVs) of cervical malignancy. HPVs rarely associated with malignancy are classified as lower-risk HPVs (lrHPVs).

Materials and Methods

Dacron-swab anal-cytology specimens were collected from and data complete for 97% (1262/1296) of Multicenter AIDS Cohort Study (MACS) men tested for HPVs using the Linear Array assay. Multivariate Poisson regression analyses estimated adjusted prevalence ratios for Group 1/2 hrHPVs and lrHPVs, controlling for the effects of age, race, ethnicity, sexual partnerships, smoking; HIV-infection characteristics, treatment, and immune status among HIV-infected men.

Results

HIV-infected men showed 35–90% higher prevalence of Group 1/2 hrHPVs and lrHPVs than HIV-uninfected men, and higher prevalence of multi-Type, and multiple risk-group infections. CD4+ T-cell count was inversely associated with HPV Group 2 prevalence (p<0.0001). The number of receptive anal intercourse (RAI) partners reported in the 24 months preceding HPV testing predicted higher prevalence of Group 1/2 hrHPVs. Men reporting ≥30 lifetime male sex partners before their first MACS visit and men reporting ≥1 RAI partners during the 24 months before HPV testing showed 17–24% and 13–17% higher prevalence of lrHPVs (p-values ≤0.05). Men reporting smoking between MACS visit 1 and 24 months before HPV testing showed 1.2-fold higher prevalence of Group 2 hrHPVs (p = 0.03). Both complete adherence to CART (p = 0.02) and HIV load <50 copies/mL (p = 0.04) were protective for Group 1 hrHPVs among HIV-infected men.

Conclusions

HIV-infected men more often show multi-type and multi-group HPV infections HIV-uninfected men. Long-term mutual monogamy and smoking cessation, generally, and CART-adherence that promotes (HIV) viremia control and prevents immunosuppression, specifically among HIV-infected MSM, are important prevention strategies for HPV infections that are relevant to anal cancer.

Diseases associated with human papillomavirus infection

Human papillomaviruses (HPVs) are ubiquitous, well adapted to their host and cleverly sequestered away from immune responses. HPV infections can be productive, subclinical or latent in both skin and mucosa. The causal association of HPV with cervical cancer, and increasingly with rising numbers of squamous cell carcinomas at other sites in both men and women, is increasingly recognised, while the morbidity of cutaneous HPV lesions, particularly in the immunosuppressed population is also significant. This chapter sets out the range of infections and clinical manifestations of the consequences of infection and its persistence and describes why HPVs are both highly effective pathogens and carcinogens, challenging to eliminate.

Expressed prostate secretions in the study of human papillomavirus epidemiology in the male

Introduction

Exploring different sampling sites and methods is of interest for studies of the epidemiology of HPV infections in the male. Expressed prostate secretions (EPS) are obtained during digital rectal examination (DRE), a daily routine urological diagnostic procedure, following massage of the prostate.

Materials and Methods

Urethral swabs and EPS samples were obtained from a consecutive sample of 752 men (mean age 32.4 years; median life-time sex partners 34) visiting urology outpatient clinics in St. Petersburg, Russia and tested for HPV DNA by general primer PCR, followed by genotyping using Luminex.

Results

Overall, 47.9% (360/752) of men were HPV-positive, with 42.0% (316/752) being positive for high-risk (HR-) HPV and 12.6% (95/752) for multiple HPV types. HPV-positivity in the EPS samples was 32.6% (27.7% HR-HPV) and in the urethral samples 25.9% (24.5% HR-HPV). 10.6% were HPV positive in both EPS and urethral samples. 6.4% had the same HPV-type in both EPS and urethral samples. 10.6% were HPV positive in both EPS and urethral samples. 6.4% had the same HPV-type in both EPS and urethral samples. The concordance between the urethral samples and EPS was 62.5% (470/752), with 80 cases double positive and 390 cases double negative in both sites. The sensitivity of urethral samples for overall HPV detection was 54.2% (195/360). Compared to analysis of urethral samples only, the analysis of EPS increased the HPV prevalence in this population with 26.2%.

Conclusion

EPS represent informative sampling material for the study of HPV epidemiology in the male.

Anal squamous carcinoma: a new AIDS-defining cancer? Case report and literature review

Squamous anal cell carcinoma is a rare malignancy that represents the 1.5% to 2% of all the lower digestive tract cancers. However, an increased incidence of invasive anal carcinoma is observed in HIV-seropositive population since the widespread of highly active antiretroviral therapy. Human papillomavirus is strongly associated with the pathogenesis of anal cancer. Anal intercourse and a high number of sexual partners appear to be risk factors to develop anal cancer in both sexes. Anal pain, bleeding and a palpable lesion in the anal canal are the most common clinical features. Endo-anal ultrasound is the best diagnosis method to evaluate the tumor size, the tumor extension and the infiltration of the sphincter muscle complex. Chemoradiotherapy plus antiretroviral therapy are the recommended treatments for all stages of localized squamous cell carcinoma of the anal canal in HIV-seropositive patients because of its high rate of cure. Here we present an HIV patient who developed a carcinoma of the anal canal after a long time of HIV infection under highly active antiretroviral therapy with a good virological and immunological response.

High prevalence of anal human papillomavirus infection and associated risky behaviors in men infected with human immunodeficiency virus in Taiwan

A cross-sectional study was conducted to investigate the prevalence, types, and risk factors associated with anal HPV infection among HIV-infected men in outpatient clinics at an AIDS designated hospital in Taiwan. Anal swabs were collect and PCR (polymerase chain reaction) was used to analyze the types of anal HPV infection. HPV DNA was detected in 74.2% of the 198 participants, including high-risk types (40.4%), low-risk types (18.2%) and multiple-types (6%). The most common types were HPV 16 (13.1%), 6 (10.4%), 11 (7.1%) and 18 (6.1%). The significant risk factor for being infected with any type or a high-risk type of HPV was having sexual partners (>3) in the preceding 6 months. Low-risk type of anal HPV infection was associated with a history of anal lesions. Our findings support the need for regular follow-up of all HIV/HPV coinfected patients and their partners to allow early detection of anal intraepithelial neoplasia.

Systematic review of the incidence and prevalence of genital warts

BACKGROUND

Anogenital warts (AGWs) are a common, highly infectious disease caused by the human papillomavirus (HPV), whose high recurrence rates contribute to direct medical costs, productivity loss and increased psychosocial impact. Because of the lack of a systematic review of the epidemiology of AGWs in the literature, this study reviewed the published medical literature on the incidence and prevalence of AGWs.

METHODS

A comprehensive literature search was performed on the worldwide incidence and prevalence of AGWs between 2001 and 2012 using the PubMed and EMBASE databases. An additional screening of abstracts from relevant sexual health and infectious disease conferences from 2009 to 2011 was also conducted. Only original studies with general adult populations (i.e., at least including ages 20 through 40 years) were included.

RESULTS

The overall (females and males combined) reported annual incidence of any AGWs (including new and recurrent) ranged from 160 to 289 per 100,000, with a median of 194.5 per 100,000. New AGW incidence rates among males ranged from 103 to 168 per 100,000, with a median of 137 per 100,000 and among females from 76 to 191 per 100,000, with a median of 120.5 per 100,000 per annum. The reported incidence of recurrent AGWs was as high as 110 per 100,000 among females and 163 per 100,000 among males. Incidence peaked before 24 years of age in females and between 25 and 29 years of age among males. The overall prevalence of AGWs based on retrospective administrative databases or medical chart reviews or prospectively collected physician reports ranged from 0.13% to 0.56%, whereas it ranged from 0.2% to 5.1% based on genital examinations.

CONCLUSIONS

The literature suggests that AGWs are widespread and the prevalence depends on study methodology as suggested by higher rates reported from routine genital examinations versus those from treatment records. However, there remains a need for more population-based studies from certain regions including Africa, Latin America and Southern Asia to further elucidate the global epidemiology of this disease.

Anal cytological abnormalities and epidemiological correlates among men who have sex with men at risk for HIV-1 infection

Background

The incidence of anal cancer, a Human Papillomavirus (HPV)-related neoplasia, has been increasing in recent decades, mainly in men who have sex with men (MSM). Cytological changes of the anal epithelium induced by HPV can be detected through an anal pap smear. This study aimed to evaluate the prevalence and epidemiological correlates of anal cytological abnormalities among relatively young MSM at risk for HIV-1 infection, to help clarify whether or not this population deserves further investigation to assess the presence of anal cancer precursor lesions.

Methods

MSM were recruited among attendees of a large STI clinic for a HIV-1 screening program. Anal samples, collected with a Dracon swab in PreservCyt, were used both for liquid-based cytology and HPV testing by the Linear Array HPV Genotyping Test. Data regarding socio-demographic characteristics and sexual behavior were collected in face-to-face interviews.

Results

A total of 346 MSM were recruited (median age 32 years). Overall, 72.5% of the individuals had an anal HPV infection, with 56.1% of them being infected by oncogenic HPV genotypes. Anal cytological abnormalities were found in 29.8% of the cases (16.7% ASC-US and 13.1% L-SIL). Presence of ASC-US+ was strongly associated with infection by any HPV type (OR=4.21, 95% CI: 1.97-9.23), and particularly by HPV 16 and/or 18 (OR=5.62, 95% CI: 2.33-13.81). A higher proportion of ASC-US+ was found in older MSM, in those with a higher number of lifetime partners and in those with a history of ano-genital warts. However, none of these variables or the others analyzed showed any significant association with abnormal cytological findings.

Conclusions

The presence of anal cytological abnormalities in about one third of the recruited MSM and their strong association with HPV infection, in particular that caused by HPV 16 and/or 18, might provide a further complement to the data that now support the introduction of HPV vaccination among MSM to protect them from the development of HPV-associated diseases. Additional studies are needed to determine whether and how screening for anal cancer precursor lesions should be performed in younger MSM.

HPV infection, anal intra-epithelial neoplasia (AIN) and anal cancer: current issues

BACKGROUND

Human papillomavirus (HPV) is well known as the major etiological agent for ano-genital cancer. In contrast to cervical cancer, anal cancer is uncommon, but is increasing steadily in the community over the last few decades. However, it has undergone an exponential rise in the men who have sex with men (MSM) and HIV + groups. HIV + MSM in particular, have anal cancer incidences about three times that of the highest worldwide reported cervical cancer incidences.

DISCUSSION

There has therefore traditionally been a lack of data from studies focused on heterosexual men and non-HIV + women. There is also less evidence reporting on the putative precursor lesion to anal cancer (AIN - anal intraepithelial neoplasia), when compared to cervical cancer and CIN (cervical intraepithelial neoplasia). This review summarises the available biological and epidemiological evidence for HPV in the anal site and the pathogenesis of AIN and anal cancer amongst traditionally non-high risk groups.

SUMMARY

There is strong evidence to conclude that high-grade AIN is a precursor to anal cancer, and some data on the progression of AIN to invasive cancer.

Premalignant lesions of the anal canal and squamous cell carcinoma of the anal canal

Squamous cell carcinoma of the anus (SCCA) is a rare tumor. However, its incidence has been increasing in men and women over the past 25 years worldwide. Risk factors associated with this cancer are those behaviors that predispose individuals to human papillomavirus (HPV) infection and immunosuppression. Anal cancer is generally preceded by high-grade anal intraepithelial neoplasia (HGAIN), which is most prevalent in human immunodeficiency virus-positive men who have sex with men. High-risk patients may benefit from screening. The most common presentation is rectal bleeding, which is present in nearly 50% of patients. Twenty percent of patients have no symptoms at the time of presentation. Clinical staging of anal cancer requires a digital rectal exam and a positron emission tomography/computed tomography scan of the chest, abdomen, and pelvis. Endorectal/endoanal ultrasound appears to add more-specific staging information when compared with digital rectal examination alone. Treatment of anal cancer prior to the 1970s involved an abdominoperineal resection. However, the current standard of care for localized anal cancer is concurrent chemoradiation therapy, primarily because of its sphincter-saving and colostomy-sparing potential. Studies have addressed alternative chemoradiation regimens to improve the standard protocol of fluorouracil, misogynic, and radiation, but no alternative regimen has proven superior. Surgery is reserved for those patients with residual disease or recurrence.

Prevalence, genotype diversity and determinants of anal HPV infection in HIV-uninfected men having sex with men

BACKGROUND

Anal human papillomavirus (HPV) infection is very common in men having sex with men (MSM), but the available data on its burden and characteristics mainly concern HIV-infected individuals.

OBJECTIVES

This study aimed to assess the prevalence, spectrum of genotypes, and determinants of the anal HPV infection in metropolitan HIV-1 uninfected MSM.

STUDY DESIGN

A cohort of 258 MSM (median age 32 years, IQR 26-39) enrolled at an STI Clinic was screened for anal HPV infection using a highly sensitive PCR-based genotyping method. Medical history and behavioral data were collected.

RESULTS

Overall, 74.8% of the MSM were HPV-positive, with 56.2% of the participants being infected by high-risk (HR) types. A multiple infection was detected in 65.3% of the HPV-positive MSM, with up to 10 different HPV types detected in the same sample. A broad spectrum of infecting HPV types was observed, with 36 different types found overall and HPV16 representing the most common type (17.8%). The lifetime and recent number of sexual partners as well as having receptive anal sex were significantly associated with the anal HPV infection, confirming the role of sexual behavior in risk of HPV infection. However, neither younger age at first intercourse nor inconsistent use of condom was significantly associated with the infection.

CONCLUSIONS

The present findings highlight the need to create a more significant awareness about the risk of anal HPV infection among HIV-uninfected MSM and warrant the investigation of possible anal intraepithelial lesions, particularly in view of the increasing anal cancer incidence in high-risk populations.

The epidemiology of anal human papillomavirus infection among women and men having sex with women

The goal of this review is to summarise epidemiological data that support an understanding of the natural history of anal human papillomavirus (HPV) among women and men having sex with women (MSW). HPV is a common infection of the anal canal among women and MSW. Although there have been a limited number of studies to date, both oncogenic and nononcogenic HPV genotypes commonly occur among these populations even when individuals do not report receptive anal sex. Genotype distribution is quite diverse, with recent studies typically detecting more than two dozen genotypes in the anal canal in samples of women and MSW. Factors most consistently associated with HPV in the anal canal among both women and MSW are lifetime number of sexual partners and detection of HPV at the genitals. The common finding of genotypic concordance between the genitals and anal canal in women and MSW, and the infectious nature of HPV, in addition to a limited number of studies offering empirical evidence of anal-to-genital self-inoculation and evidence of HPV hand carriage, may help explain the detection of HPV in the anal canal outside the context of receptive anal sex. HPV vaccination has been shown to reduce anal HPV infection among women and is also a promising prevention strategy among MSW.