Epidemiology, natural history and risk factors for anal intraepithelial neoplasia

Identifying risk factors for prevalent anal human papillomavirus type 16 infection in women living with HIV

Background

Women living with HIV (WLHIV) have a high risk of anal cancer. Identifying risk factors for anal HPV 16 infection, the most significant risk factor for anal cancer, is essential for prevention and screening strategies.

Methods

In the EVVA Cohort study, 151 WLHIV had cervical and anal HPV testing with genotyping every 6 months for 2 years, while demographic and clinical data were collected via questionnaires and chart reviews. Here, we present results of baseline data analyzed using multivariable logistic regression.

Results

Among 150 women with adequate HPV test results at baseline, HPV 16 DNA was detected anally in 23 (15.3%; 95%CI:10.4–22.1) and cervically in 5 (3.3%; 95%CI:1.4–7.8). In multivariable analysis, current smoking (OR = 6.0; 95%CI: 1.5–23.9), nadir CD4 count ≤ 200 cells/μL (OR = 8.4; 95%CI: 2.0–34.3), prevalent cervical HPV 16 (OR = 14.7; 95%CI: 1.0–222.5) and anogenital herpes in previous 6 months (OR = 9.8, 95%CI: 1.7–56.8) were associated with prevalent anal HPV 16.

Conclusions

Knowledge of risk factors can help identify WLHIV at greatest risk of anal HPV 16 infection and, potentially, developing subsequent anal cancer. Identification of the subgroup of these women in whom HPV 16 persists could be an early step in the algorithm of anal cancer screening.

Human Immunodeficiency Virus Infection Promotes Human Papillomavirus-Mediated Anal Squamous Carcinogenesis: An Immunologic and Pathobiologic Review

BACKGROUND

Anal squamous cell carcinoma (SCC) is a rare gastrointestinal malignancy with rising incidence, both in the United States and internationally. The primary risk factor for anal SCC is human papillomavirus (HPV) infection. However, there is a growing burden of disease in patients with human immunodeficiency virus (HIV) and HPV coinfection, with the incidence of anal SCC significantly increasing in this population. This is particularly true in HIV-infected men. The epidemiologic correlation between HIV-HPV coinfection and anal SCC is established; however, the immunologic mechanisms underlying this relationship are not well understood.

SUMMARY

HIV-related immunosuppression due to low circulating CD4+ T cells is one component of increased risk, but other mechanisms, such as the effect of HIV on CD8+ T lymphocyte tumor infiltration and the PD-1/PD-L1 axis in antitumor and antiviral response, is emerging as significant contributors. The goal of this article is to review existing research on HIV-HPV coinfected anal SCC and precancerous lesions, propose explanations for the detrimental synergy of HIV and HPV on the pathogenesis and immunologic response to HPV-associated cancers, and discuss implications for future treatments and immunotherapies in HIV-positive patients with HPV-mediated anal SCC. Key Messages: The incidence of anal squamous cell carcinoma is increased in human immunodeficiency virus (HIV)-infected patients, even in patients on highly active antiretroviral therapy. Locoregional HIV infection may enhance human papillomavirus oncogenicity. Chronic inflammation due to HIV infection may contribute to CD8+ T lymphocyte exhaustion by upregulating PD-1 expression, thereby blunting cytotoxic antitumor response.

HIV, Immune Dysfunction, and the Natural History of Anal High-Risk Human Papillomavirus Infection in Gay and Bisexual Men

BACKGROUND

Incidence of anal cancer is highest in gay and bisexual men (GBM). Better understanding of the natural history of anal high-risk human papillomavirus (hrHPV) infection is needed for anal cancer prevention.

METHODS

The Study of the Prevention of Anal Cancer was a 3-year study of Australian GBM, aged 35 years or older. We examined incidence, clearance, and risk factors for 13 hrHPV types at baseline and 3 annual visits.

RESULTS

In 525 men with ≥ 2 visits, 348 (66.3%) acquired ≥ 1 incident hrHPV infection. HPV16 incidence rates were similar, but non-16 hrHPV incidence was higher in HIV-positive (51.8/100 person years [PY]) than HIV-negative men (36.5/100 PY, P < .001). Annual clearance rates of HPV16 (13.21/100 PY, 95% confidence interval, 10.53-16.56) were lower than for other hrHPV types. hrHPV clearance rates were not associated with HIV overall but were significantly lower in those with a lower nadir CD4 (<200 cells/µL) for HPV16 (P = .015) and other hrHPV types (P = .007).

CONCLUSIONS

Higher incidence of non-16 hrHPV types, coupled with lower clearance of non-16 hrHPV types in those with past impaired immune function, is consistent with the greater role of non-16 hrHPV in anal cancer in HIV-positive people.

AUSTRALIA NEW ZEALAND CLINICAL TRIALS REGISTRY

ANZCTR365383.

Early Detection of Anal High-Grade Squamous Intraepithelial Lesion: Do We Have an Impact on Progression to Invasive Anal Carcinoma?

OBJECTIVE

Anal high-grade squamous intraepithelial lesion (HSIL) may precede invasive cancer and can be detected clinically or during high-resolution anoscopy (HRA). The aims of this study were to compare the characteristics of HSIL discovered by HRA or in a surgical specimen without clinically visible lesion when diagnosed versus macroscopic HSIL when first diagnosed and then to compare their progression to invasive cancer.

PATIENTS AND METHODS

Clinical records of all patients with at least one HSIL lesion confirmed by histology and evaluated by HRA in a single center between September 1, 2009, and April 30, 2017, were retrospectively reviewed. The center's histological anal cancer data base was questioned in December 2017 to identify all cases.

RESULTS

During a median (interquartile range) follow-up of 19.1 (5.6-40.2) months, 12 (2.9%) anal cancers were diagnosed in patients with a diagnosis of HSIL. Period of time between the first diagnosis of anal lesion and the cancer was 28.8 months (interquartile range = 15.4-65.6), and 11 (92%) of 12 were diagnosed as superficially invasive squamous cell carcinoma or T1N0M0. The rate of progression to anal cancer differed significantly between patients with macroscopic HSIL at diagnosis (5.4%) and patients with microscopic HSIL diagnosed during HRA (0.9%) (p = .01).

CONCLUSIONS

Patients with macroscopic histologically proven HSIL at first diagnosis of anal intraepithelial lesion have a significantly higher risk of anal cancer compared with patients with microscopic lesions diagnosed during HRA, but the duration between the first diagnosis of HSIL and cancer does not differ between the 2 groups.

Practice parameters for the diagnosis and treatment of anal intraepithelial neoplasia (AIN) on behalf of the Italian Society of Colorectal Surgery (SICCR)

Squamous cell carcinoma (SCC) of the anus is a human papilloma virus (HPV) related malignancy that is preceded by anal intraepithelial neoplasia (AIN) making this cancer, at least theoretically, a preventable disease. In the past 10 years the diagnosis, management and nomenclature of AIN has dramatically changed. Increased life expectancy in human immunodeficiency virus (HIV) positive patients due to highly active antiretroviral therapy (HAART) has caused an increase in the incidence of SCC of the anus. While many experts recommend screening and treatment of anal high-grade squamous intraepithelial lesion (HSIL), there is no consensus on the optimal management these lesions. Therefore, there is a need to review the current evidence on diagnosis and treatment of AIN and formulate recommendations to guide management. Surgeons who are members of the Italian Society of Colorectal Surgery (SICCR) with a recognized interest in AIN were invited to contribute on various topics after a comprehensive literature search. Levels of evidence were classified using the Oxford Centre for Evidence-based Medicine of 2009 and the strength of recommendation was graded according to the United States (US) preventive services task force. These recommendations are among the few entirely dedicated only to the precursors of SCC of the anus and provide an evidence-based summary of the current knowledge about the management of AIN that will serve as a reference for clinicians involved in the treatment of patients at risk for anal cancer.

Human Papillomavirus Correlates With Histologic Anal High-Grade Squamous Intraepithelial Lesions in Hispanics With HIV

OBJECTIVE

To estimate the magnitude of association between anal infection with high-risk human papilloma virus (HR-HPV) types and severity of biopsy-confirmed histopathological anal squamous intraepithelial lesions (SILs) among a clinic-based sample of HIV-infected adults in Puerto Rico.

METHODS

This cross-sectional study analyzed data from medical records of adult patients who visited a specialized anal neoplasia clinic from June 2015 to December 2017 (n = 239); sociodemographics, behavioral risk factors, medical history, clinical data, and pathology reports were collected. The magnitude of association between anal HR-HPV and severity of anal SIL, adjusted for potential confounders, was assessed using a multinomial logistic model.

RESULTS

A 78.7% of patients had anal HR-HPV infection, 43.9% had histopathological low-grade SIL (LSIL), and 37.7% had histopathological high-grade SIL (HSIL). The prevalence of anal HR-HPV infection was 63.6% among patients with no anal SIL, 70.5% for those with LSIL and 95.6% for those with HSIL. After adjusting for different predictors, patients with anal HR-HPV infection were more likely to have HSIL (odds ratio, 11.0; 95% confidence interval, 3.2-37.2) than those without anal HR-HPV infection, whereas no significant excess was observed for LSIL (odds ratio, 1.4; 95% confidence interval, 0.6-3.1).

CONCLUSIONS

This study showed a strong association between anal HR-HPV infection and HSIL. Likewise, a high prevalence of anal HR-HPV infection and presence of anal SIL was observed among HIV-infected individuals. Our result highlights the importance of screening for anal HR-HPV infection and anal SIL and optimizing strategies for HPV vaccination in HIV-infected individuals.

HPV positive, wild type TP53, and p16 overexpression correlate with the absence of residual tumors after chemoradiotherapy in anal squamous cell carcinoma

Background

Anal residual tumors are consensually identified within six months of chemoradiotherapy and represent a persistent lesion that may have prognostic value for overall survival. The aim of this study was to evaluate the association of HPV and HIV status, p16 expression level and TP53 mutations with the absence of residual tumors (local response) in Squamous Cell Carcinoma (SCC) of the anal canal after chemoradiotherapy.

Methods

We performed a study on 78 patients with SCC of the anal canal who submitted to chemoradiotherapy and were followed for a six-month period to identify the absence or presence of residual tumors. HPV DNA was identified by polymerase chain reaction and direct sequencing, HIV RNA was detected by TaqMan amplification, p16 expression was detected by western blotting, and the mutational analysis of TP53 was performed by direct sequencing; additionally, samples carrying mutations underwent fluorescent in sit hybridization. The evaluation of the tumor response to treatment was conducted six months after the conclusion of chemoradiotherapy. The following classifications were used to evaluate the outcomes: a) no response (presence of residual tumor) and b) complete response (absence of residual tumor).

Results

The significant variables associated with the absence of residual tumors were HPV positive, p16 overexpressed, wild-type TP53, female gender, and stages I and II. Only the presence of HPV was independently correlated with the clinical response; this variable increased the chances of a response within six months by 31-fold.

Conclusions

The presence of HPV in tumor cells was correlated with the absence of a residual tumor. This correlation is valuable and can direct future therapeutic approaches in the anal canal.

Risk factors for anal high-grade squamous intraepithelial lesions in HIV-positive MSM: is targeted screening possible?

Objective:

HIV-positive MSM are at increased risk for developing anal squamous cell carcinoma. Detection of precursor lesions of anal cancer [anal high-grade squamous intraepithelial lesions (HSIL)] is cumbersome and expensive. Our objective was to identify potential risk factors for anal HSIL in HIV-positive MSM to develop more stringent screening criteria.

Design:

We studied a cohort of MSM screened by high-resolution anoscopy at three HIV clinics in Amsterdam, the Netherlands.

Methods:

For every first high-resolution anoscopy performed in a patient, we analyzed five demographic and seven HIV-related potential risk factors for four different outcome measures: histologically proven anal HSIL vs. no squamous intraepithelial lesions (SIL), HSIL-anal intraepithelial neoplasia 2 vs. no SIL, HSIL-anal intraepithelial neoplasia 3 vs. no SIL, and HSIL vs. no HSIL. We used univariable and multilevel, multivariable logistic regression.

Results:

From 2008 through 2015, 497 out of 1678 (30%) screened HIV-positive MSM had anal HSIL. The mean age was 49 years (SD 9.6), 96% used combination antiretroviral therapy, and median duration of combination antiretroviral therapy use was 7.8 years (interquartile range 4.0–12.4). Increasing age [adjusted odds ratio (aOR) 0.82, 95% confidence interval (CI) 0.70–0.94, P = 0.006] and years living with suppressed viral load [1–5 years suppressed aOR 0.52 (95% CI 0.34–0.80), 5.01–10 years aOR 0.47 (95% CI 0.29–0.74), >10 years aOR 0.54 [0.34–0.87], all compared to less than 1 year suppressed, P = 0.009] were found to be protective for HSIL vs. no SIL.

Conclusion:

Young HIV-positive MSM without viral suppression are statistically at highest risk for anal HSIL, but given the high prevalence among all virally suppressed men, we advise that all HIV-positive MSM should be screened for HSIL.

The prevalence of human papillomavirus infections and associated risk factors in men-who-have-sex-with-men in Cape Town, South Africa

BACKGROUND

We investigated the prevalence of human papillomavirus (HPV) infection and associated behavioural risk factors in men-who-have-sex-with-men (MSM) attending a clinical service in Cape Town, South Africa.

METHODS

MSM were enrolled at the Ivan Toms Centre for Men's Health in Cape Town. A psychosocial and sexual behavioral risk questionnaire was completed for each participant and urine, oro-pharyngeal and anal swabs were collected for HPV testing using the Linear Array HPV Genotyping Test. Logistic regression analyses were performed to determine sexual risk factors associated with HPV infection at the three anatomical sites.

RESULTS

The median age of all 200 participants was 32 years (IQR 26-39.5), of which 31.0 % were black, 31.5 % mixed race/coloured and 35.5 % white. The majority of the participants (73.0 %) had completed high school, 42.0 % had a tertiary level qualification and 69.0 % were employed. HPV genotypes were detected in 72.8 % [95 % CI: 65.9-79.0 %], 11.5 % [95 % CI: 7.4-16.8 %] and 15.3 % [95 % CI: 10.5-21.2 %] of anal, oro-pharyngeal and urine specimens, respectively. Prevalence of high-risk (HR)-HPV types was 57.6 % [95 % CI: 50.3-64.7 %] in anal samples, 7.5 % [95 % CI: 4.3-12.1 %] in oro-pharyngeal samples and 7.9 % [95 % CI: 4.5-12.7 %] in urine, with HPV-16 being the most common HR-HPV type detected at all sites. HPV-6/11/16/18 was detected in 40.3 % [95 % CI: 33.3-47.6 %], 4.5 % [95 % CI: 2.1-8.4 %] and 3.2 % [95 % CI: 1.2-6.8 %] of anal, oro-pharyngeal and urine samples, respectively. Multiple HPV types were more common in the anal canal of MSM while single HPV types constituted the majority of HPV infections in the oropharynx and urine. Among the 88 MSM (44.0 %) that were HIV positive, 91.8 % [95 % CI: 83.8-96.6 %] had an anal HPV infection, 81.2 % [95 % CI: 71.2-88.8 %] had anal HR-HPV and 85.9 % [95 % CI: 76.6-92.5 %] had multiple anal HPV types. Having sex with men only, engaging in group sex in lifetime, living with HIV and practising receptive anal intercourse were the only factors independently associated with having any anal HPV infection.

CONCLUSIONS

Anal HPV infections were common among MSM in Cape Town with the highest HPV burden among HIV co-infected MSM, men who have sex with men only and those that practiced receptive anal intercourse. Behavioural intervention strategies and the possible roll-out of HPV vaccines among all boys are urgently needed to address the high prevalence of HPV and HIV co-infections among MSM in South Africa.

Laser capture microdissection as a tool to evaluate human papillomavirus genotyping and methylation as biomarkers of persistence and progression of anal lesions

INTRODUCTION

Anal squamous cell carcinoma is preceded by persistent infection with high-risk human papillomavirus (HPV) and the cancer precursor, high-grade squamous intraepithelial lesion (HSIL). Detection of specific HPV genotypes and HPV-related biomarkers may be an option for primary anal screening. However, more data on the natural history of HPV-related anal lesions are required. The outcomes from this study will enhance our understanding of the clinical and biological behaviour of HPV-related anal lesions and inform the development of future HPV genotype and/or biomarker screening tests.

METHODS AND ANALYSIS

HIV-negative and HIV-positive men who have sex with men, aged 35 years and over, recruited from community-based settings in Sydney, Australia, attend 6 clinic visits over 3 years. At the first 5 visits, participants undergo a digital anorectal examination, an anal swab for HPV genotyping and anal cytology, and high-resolution anoscopy with directed biopsy of any visible abnormalities that are suggestive of any abnormality suspicious of SIL. Tissue sections from participants diagnosed with histologically confirmed HSIL at the baseline clinic visit will undergo laser capture microdissection, HPV detection and genotyping, and quantitation of CpG methylation in baseline and follow-up biopsies. Histological and cytological findings in combination with HPV genotyping data will be used to identify persistent HSIL. HSIL will be stratified as non-persistent and persistent based on their status at 12 months. The performance of HPV genotype and methylation status in predicting disease persistence at 12 months will be assessed, along with associations with HIV status and other covariates such as age.

ETHICS AND DISSEMINATION

The St Vincent's Hospital Ethics Committee granted ethics approval for the study. Written informed consent is obtained from all individuals before any study-specific procedures are performed. Findings from this study will be disseminated to participants and the community through study newsletters, and through peer-reviewed publications and international conferences.

Anal human papillomavirus and HIV: A cross-sectional study among men who have sex with men in Moscow, Russia, 2012-2013

Anal human papillomavirus (HPV) is prevalent among men who have sex with men (MSM), but has not been studied in the Russian Federation. A cross-sectional survey and HPV genotyping were conducted among HIV seropositive (n=58) and seronegative MSM (n=65)in Moscow. Multivariable logistic regression was performed to identify correlates of infection with oncogenic HPV genotypes 16 and/or 18 (HPV 16/18). Forty per cent (49/124) of all MSM were infected with at least one anal HPV genotype, 31.5% (39/124) had HPV16/18,and 11.5% (14/121) had high-grade squamous intraepithelial lesions (HSIL). HPV 16/18 was more prevalent in HIV seropositive than seronegative men (24/58,41.4% vs 15/65, 23.1%; p=0.03). HIV infection was independently associated with HPV 16/18 (adjusted odds ratio (AOR): 5.08; 95% confidence intervals (CI):1.49-17.34, p=0.01), as was having 2-4 steady male sex partners in the last year (vs ≤ 1 partner; AOR: 6.99;95%CI: 1.94–25.24, p<0.01). History of prison/detention,migration to/within Russia and use of incompatible lubricants were marginally associated with HPV16/18 (p<0.10). Comprehensive prevention options are needed to address HIV and HPV infection among MSM in Russia and may benefit from inclusion of young men in piloted HPV vaccination programmes.

Cancers of the anal canal: diagnosis, treatment and future strategies

Anal cancer is an uncommon cancer; however, it is rising in incidence. There is confusion regarding nomenclature and the distinction between anal canal cancer and anal margin cancer. This article discusses the modern definition, etiology and staging of anal canal and anal margin cancers. Modern chemotherapy and radiotherapy regimens are discussed, in addition to modern imaging and radiotherapy techniques. Future preventative strategies and potential novel treatments are discussed.

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.

Environmental scan of anal cancer screening practices: worldwide survey results

Anal squamous cell carcinoma is rare in the general population but certain populations, such as persons with HIV, are at increased risk. High-risk populations can be screened for anal cancer using strategies similar to those used for cervical cancer. However, little is known about the use of such screening practices across jurisdictions. Data were collected using an online survey. Health care professionals currently providing anal cancer screening services were invited to complete the survey via email and/or fax. Information was collected on populations screened, services and treatments offered, and personnel. Over 300 invitations were sent; 82 providers from 80 clinics around the world completed the survey. Fourteen clinics have each examined more than 1000 patients. Over a third of clinics do not restrict access to screening; in the rest, eligibility is most commonly based on HIV status and abnormal anal cytology results. Fifty-three percent of clinics require abnormal anal cytology prior to performing high-resolution anoscopy (HRA) in asymptomatic patients. Almost all clinics offer both anal cytology and HRA. Internal high-grade anal intraepithelial neoplasia (AIN) is most often treated with infrared coagulation (61%), whereas external high-grade AIN is most commonly treated with imiquimod (49%). Most procedures are performed by physicians, followed by nurse practitioners. Our study is the first description of global anal cancer screening practices. Our findings may be used to inform practice and health policy in jurisdictions considering anal cancer screening.

Why a special issue on anal cancer and what is in it?

This editorial describes the contents of this special issue of Sexual Health devoted to anal cancer. The aim of the issue is to provide readers with information to assist them in making decisions about what to do about detecting anal cancer early in men who have sex with men with HIV. Should they be advocating screening? It discusses the epidemiology of HPV infection, anal intraepithelial neoplasia, and anal cancer in MSM, heterosexual men and women; anal cancer screening and treatment of anal cancer. And most importantly, what should be done about vaccinating boys with the HPV vaccine.

Time for a strategic research response to anal cancer

Anal cancer was until recently regarded as a rare cancer of little consequence. The articles in this special edition of Sexual Health clearly demonstrate that anal cancer is increasing in incidence and, in some populations, it has become an urgent public health priority. In this summary paper, we will review the data presented in this issue and elsewhere on the magnitude of the issue, the means of prevention and treatment, and suggest a way forward.