Anal intraepithelial neoplasia

Anal and Perianal Preneoplastic Lesions

Anal cancer, mainly squamous cell carcinoma, is rare but increasing in prevalence, as is its precursor lesion, anal squamous dysplasia. They are both strongly associated with human papillomavirus infection. The 2-tiered Lower Anogenital Squamous Terminology classification, low-grade SIL and high-grade SIL, is preferred to the 3-tiered anal intraepithelial neoplasia classification because of better interobserver agreement and clearer management implications. Immunohistochemistry with p16 is helpful to corroborate the diagnosis of squamous dysplasia. Similarly, immunohistochemistry is helpful to differentiate primary Paget disease from secondary Paget disease, which is usually due to anal squamous mucosal/epidermal involvement by primary rectal adenocarcinoma.

Anal Intraepithelial Neoplasia: Precursor of Anal Squamous Cell Carcinoma

Anal squamous cell carcinoma (SCC) is rare, but it has been commonly detected as an invasive cancer. The standard treatment for anal SCC was surgical resection. However, recent medical advances have enabled the standard treatment to be chemoradiotherapy. Anal intraepithelial neoplasia (AIN) is a premalignant lesion of SCC. The screening test for AIN and human papilloma virus vaccine are important for the following high-risk patients: patients positive for human immunodeficiency virus and men who have sexual intercourse with men. Although cytology can be easily applied for a screening test, the false-negative rate for AIN is high. Instead, high-resolution anoscopy (HRA) has been gaining attention as a promising screening method for high-risk patients. Investigations comparing characteristic findings of HRA with the histology of AIN have demonstrated that HRA is a highly specific test for AIN. Magnifying or image-enhanced endoscopies are also routinely used for colonoscopy, as they allow detailed observations at higher magnifications than those of HRA. Hence, these endoscopic modalities can be applied for assessing AIN. Ablation therapies or topical medications are available as the local treatment for AIN. Although endoscopic submucosal dissection is considered to be feasible to remove AIN, it has a technical difficulty to approach endoscopically invisible areas. Hence, this technique may be useful to resect AIN localized in the endoscopically visible areas, when the localization is confirmed via targeted biopsy.

Unilateral leg weakness and pain secondary to metastatic anal squamous cell carcinoma

A 58-year-old man presented to colorectal clinic with intermittent rectal bleeding, weight loss, also pain and weakness affecting his lower back and right leg. On inspection, there were perianal warts (condyloma acuminata), with an additional palpable anal lesion on digital rectal examination, confirmed by colonoscopy. Subsequent imaging revealed a large right psoas abscess, and an associated paravertebral soft tissue component invading the right lumbosacral plexus and nerve roots at L4, L5 and S1. Biopsy of the paravertebral mass revealed metastatic squamous cell carcinoma. Given his symptomatology, and also as biopsy of the perianal warts revealed high-grade squamous intraepithelial lesion/grade III anal intraepithelial neoplasia on histology with infection by human papillomavirus type 6, the primary was presumed to be anal. This was a case of sciatic pain which proved to be diagnostically challenging on initial presentation to primary care. This mode of presentation and pattern of metastasis are uncommon in anal cancer.

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.

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.

Anal intraepithelial neoplasia: diagnosis, screening, and treatment

Anal intraepithelial neoplasia (AIN) is a premalignant lesion for anal cancer. It is more commonly found in high-risk patients (e.g., human papilloma virus (HPV)/human immunodeficiency virus infections, post-organ transplantation patients, and men who have sex with men) and development is driven by HPV infection. The incidence of AIN is difficult to estimate, but is heavily skewed by preexisting conditions, particularly in high-risk populations. The diagnosis is made from cytology or biopsy during routine examinations, and can be performed at a primary care provider’s office. A pathologist can then review and classify cells, based on nucleus-to-cytoplasm ratios. The classification of low or high grade can better predict progression from AIN to anal cancer. There is little debate that AIN can develop into anal cancer, and the main rationale for treatment is to delay the progression. Significant controversy remains regarding screening, surveillance, and treatment for AIN. Management options are separated into surveillance (watchful waiting) and interventional strategies. Emerging data suggest that close patient follow up with a combination of ablative and topical treatments may offer the greatest benefit. HPV vaccination offers a unique treatment prior to HPV infection and the subsequent development of AIN, but its use after the development of AIN is limited. Ablative treatment includes excision, fulguration, and laser therapy.

Anal Intraepithelial Neoplasia and Squamous Cell Cancer of the Anus

Anal intraepithelial neoplasia (AIN) is the premalignant condition of the anal squamous tissue. It is associated with the human papilloma virus and is considered the transition prior to the invasive anal squamous cell carcinoma. It is typically asymptomatic and can be either an incidental finding after anorectal surgery or identified when high-risk patient populations are screened. Once AIN is diagnosed, the optimal management remains controversial, partly because the natural history of the disease is unclear. Surgical management of the disease has essentially been replaced by more conservative treatment options and can range from expectant management to topical therapy to photodynamic therapy. The aim of this article is to review the varied treatment options and to briefly review prevention strategies.

Clinical evaluation of anal intraepithelial neoplasia: are we missing the boat?

BACKGROUND

Anal intraepithelial neoplasia (AIN) is dysplasia in the epithelium of the anus and is a pre-malignant condition associated with a low rate of progression to invasive squamous cell carcinoma (SCC). The natural history of progression for AIN to anal SCC is poorly defined. This study aims to review our experience with AIN and investigate the natural history of progression.

METHODS

Data on all patients with AIN from January 2005 to December 2015 were retrospectively reviewed. Three separate databases were searched - Colorectal, Radiation Oncology and Infectious Diseases. All databases were cross-referred to obtain a complete but non-duplicated data set. Electronic charts were reviewed to obtain clinical information.

RESULTS

Twenty-eight patients were identified with AIN of various grades. There were 25 males, three females. Twenty of the male patients were human immunodeficiency virus (HIV) positive. Mean length of follow up was 56 months. Complete regression of AIN to normal was noted in 13 patients (46%). Four patients had persisting AIN III with no evidence of regression or malignant transformation. Nine patients with pre-existing AIN developed SCC (32%). Seven were positive for HIV infection (all males). Median time to progression was 36 months. None of the patients demonstrated clear linear pattern of progression of AIN to SCC.

CONCLUSION

High grade AIN may progress to anal SCC and surveillance is indicated. The exact natural history of progression for AIN is difficult to predict. There is no linear progression over time evident. HIV patients with AIN are at higher risk of developing SCC.

Syndemic synergy of HPV and other sexually transmitted pathogens in the development of high-grade anal squamous intraepithelial lesions

Background

Anal intraepithelial neoplasia is associated with high-risk human papillomavirus (hrHPV) as a precursor to anal cancer. However, factors other than hrHPV are likely to be involved and further study of cofactors is required because of the possibility of syndemic interactions.

Methods

Three hundred and fourteen patients underwent 457 operations. Histopathology and hrHPV testing using the Digene Hybrid Capture 2 (HC 2) method were performed. Demographic factors and sexually transmissible infections (STIs) were recorded.

Results

Results showed that hrHPV alone was associated with HSIL (OR = 4.65, p < 0.001). None of the other STIs were alone associated with HSIL but amplification of risk was found when hrHPV infection occurred with HIV (OR = 11.1); syphilis (OR = 5.58); HSV 2 (OR = 7.85); gonorrhoea (OR = 6.45) and some other infections.

Conclusions

These results suggest that hrHPV is a sufficient cause of anal HSIL. Seropositivity for HIV, HSV 2, T. pallidum, HBV and HCV and a history of gonorrhoea or chlamydia exert a powerful amplifying factor increasing the risk of HSIL above the risk with hrHPV alone. Other co-factors which are associated with an increased risk of HSIL are increased age, male gender, MSM behaviour and self-reported history of more than 50 sexual partners. This pattern of disease in patients with warts is characteristic of a syndemic with potential serious increased risk of anal carcinoma.

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High-risk HPV is a necessary and sufficient cause of progression from LSIL to HSIL.

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HIV, HSV 2, HBV and HCV are associated with an amplified risk of hrHPV induced HSIL.

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Gonorrhoea, chlamydia, and syphilis are associated with increased odds HSIL.

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HSIL shows syndemic interaction patterns with STIs and behavioural/social factors.

Background and Current Treatment of Squamous Cell Carcinoma of the Anus

In this review, a summary of our current understanding of squamous cell carcinoma of the anus (SCCA) and the advances in our knowledge of SCCA regarding screening, prevention, the role of the immune system, current treatment and the potential for novel targets are discussed. The present standard of care in terms of treatment is 5-fluorouracil (5-FU) and mitomycin C (MMC) concurrently with radiation, which results in a high level of disease control for small early cancers. Preservation of the anal sphincter is achieved in the majority, although anorectal function is often impaired. Although evidence from prospective studies to support a change in the treatment strategy is lacking, patients with HPV-negative SCCA appear to be less responsive to chemoradiation (CRT) and relapse more frequently. In contrast, HPV-positive tumours usually fare better, but oncological outcomes are modified by smoking and immune incompetence. There is current interest in escalating the radiotherapy dose for larger, more advanced tumours, and de-escalating treatment for HPV-positive tumours. The use of novel immunological treatments to target the underlying different molecular pathways of HPV-positive cancers is exciting.

Front-to-back & dabbing wiping behaviour post-toilet associated with anal neoplasia & HR-HPV carriage in women with previous HPV-mediated gynaecological neoplasia

BACKGROUND

Anal cancer is a human papillomavirus (HPV)-mediated neoplasia of the anal squamous epithelium. Anal cancer is much more common among women, particularly those with a previous high-grade gynaecological neoplasia.

METHODS

Cross-sectional study of women with a previous HPV-mediated gynaecological neoplasia in Tasmania, Australia. Women presenting for follow-up gynaecological care had anal swab samples taken for anal cytology by Hologic Liquid ThinPrep, followed by HPV genotyping. Women with abnormal anal cytology were invited for high-resolution anoscopy. Potential risk factors, including post-toilet wiping behaviours, were queried by questionnaire while clinical covariates were extracted from medical records. Covariates of anal outcomes evaluated by log-binomial and log-multinomial regression.

RESULTS

From 163 women enrolled in the study, 65 (39.9%) had abnormal cytology, with 46 (28.2%) being high-grade. Of the 50 women with abnormal anal cytology having high-resolution anoscopy, 32 (64.0%) had abnormal histology with 13 (26.0%) being high-grade. Of the 123 women tested for HR-HPV DNA, 48 (39.0%) had HR-HPV detected, the most common genotypes being 16 and 51 (14/123, 11.4% for both). In addition to some known anal cancer risk factors, we found front-to-back wiping was associated with significantly increased (Prevalence ratio (PR) range: 1.99-3.60) prevalence of cytological and histological abnormality and HR-HPV carriage/co-carriage, while dabbing post-toilet was significantly associated with decreased prevalences (PR range: 0.50-0.62).

CONCLUSIONS

Post-toilet wiping behaviours were significantly associated with the prevalence of anal cytological, histological and HR-HPV carriage outcomes. This suggests a biologically plausible mechanism for HR-HPV introduction and the higher frequencies of anal neoplasia in women.

Screening, Surveillance, and Treatment of Anal Intraepithelial Neoplasia

The prevalence of anal intraepithelial neoplasia has been increasing, especially in high-risk patients, including men who have sex with men, human immunodeficiency virus positive patients, and those who are immunosuppressed. Several studies with long-term follow-up have suggested that rate of progression from high-grade squamous intraepithelial lesions to invasive anal cancer is ∼ 5%. This number is considerably higher for those at high risk. Anal cytology has been used to attempt to screen high-risk patients for disease; however, it has been shown to have very little correlation to actual histology. Patients with lesions should undergo history and physical exam including digital rectal exam and standard anoscopy. High-resolution anoscopy can be considered as well, although it is of questionable time and cost-effectiveness. Nonoperative treatments include expectant surveillance and topical imiquimod or 5-fluorouracil. Operative therapies include wide local excision and targeted ablation with electrocautery, infrared coagulation, or cryotherapy. Recurrence rates remain high regardless of treatment delivered and surveillance is paramount, although optimal surveillance regimens have yet to be established.

Optimization of heterologous DNA-prime, protein boost regimens and site of vaccination to enhance therapeutic immunity against human papillomavirus-associated disease

Background

Human papillomavirus (HPV) has been identified as the primary etiologic factor of cervical cancer as well as subsets of anogenital and oropharyngeal cancers. The two HPV viral oncoproteins, E6 and E7, are uniquely and consistently expressed in all HPV infected cells and are therefore promising targets for therapeutic vaccination. Both recombinant naked DNA and protein-based HPV vaccines have been demonstrated to elicit HPV-specific CD8+ T cell responses that provide therapeutic effects against HPV-associated tumor models. Here we examine the immunogenicity in a preclinical model of priming with HPV DNA vaccine followed by boosting with filterable aggregates of HPV 16 L2E6E7 fusion protein (TA-CIN).

Results

We observed that priming twice with an HPV DNA vaccine followed by a single TA-CIN booster immunization generated the strongest antigen-specific CD8+ T cell response compared to other prime-boost combinations tested in C57BL/6 mice, whether naïve or bearing the HPV16 E6/E7 transformed syngeneic tumor model, TC-1. We showed that the magnitude of antigen-specific CD8+ T cell response generated by the DNA vaccine prime, TA-CIN protein vaccine boost combinatorial strategy is dependent on the dose of TA-CIN protein vaccine. In addition, we found that a single booster immunization comprising intradermal or intramuscular administration of TA-CIN after priming twice with an HPV DNA vaccine generated a comparable boost to E7-specific CD8+ T cell responses. We also demonstrated that the immune responses elicited by the DNA vaccine prime, TA-CIN protein vaccine boost strategy translate into potent prophylactic and therapeutic antitumor effects. Finally, as seen for repeat TA-CIN protein vaccination, we showed that the heterologous DNA prime and protein boost vaccination strategy is well tolerated by mice.

Conclusions

Our results provide rationale for future clinical testing of HPV DNA vaccine prime, TA-CIN protein vaccine boost immunization regimen for the control of HPV-associated diseases.

Electronic supplementary material

The online version of this article (doi:10.1186/s13578-016-0080-z) contains supplementary material, which is available to authorized users.

Systematic review of guidelines for the assessment and management of high-grade anal intraepithelial neoplasia (AIN II/III)

AIM

There is ambiguity with regard to the optimal management of anal intraepithelial neoplasia (AIN) III. The aim of this review was to assess and compare international/national society guidelines currently available in the literature on the management, treatment and surveillance of AIN III. We also aimed to assess the quality of the studies used to compile the guidelines and to clarify the terminology used in histological assessment.

METHOD

An electronic search of PubMed and Embase was performed using the search terms 'anal intraepithelial neoplasia', 'AIN', 'anal cancer', 'guidelines', 'surveillance' and 'management'. Literature reviews and guidelines or practice guidelines in peer reviewed journals from 1 January 2000 to 31 December 2014 assessing the treatment, surveillance or management of patients with AIN related to human papilloma virus were included. The guidelines identified by the search were assessed for the quality of evidence behind them using the Oxford Centre for Evidence-based Medicine 2011 Levels of Evidence.

RESULTS

The database search identified 5159 articles and two further guidelines were sourced from official body guidelines. After inclusion criteria were applied, 28 full-text papers were reviewed. Twenty-five of these were excluded, leaving three guidelines for inclusion in the systematic review: those published by the Association of Coloproctology of Great Britain and Ireland, the American Society of Colon and Rectal Surgeons and the Italian Society of Colorectal Surgery. No guidelines were identified on the management of AIN III from human papilloma virus associations and societies. All three guidelines agree that a high index of clinical suspicion is essential for diagnosing AIN with a disease-specific history, physical examination, digital rectal examination and anal cytology. There is interchange of terminology from high-grade AIN (HGAIN) (which incorporates AIN II/III) and AIN III in the literature leading to confusion in therapy use. Treatment varies from immunomodulation and photodynamic therapy to targeted destruction of areas of HGAIN/AIN II/III using infrared coagulation, electrocautery, cryotherapy or surgical excision but with little consensus between the guidelines. Recommendations on surveillance strategies are similarly discordant, ranging from 6-monthly physical examination to annual anoscopy ± biopsy. Over 50% of the recommendations are based on Level 3 or Level 4 evidence and many were compiled using studies that were more than 10 years old.

CONCLUSION

Despite concordance regarding diagnosis, there is significant variation in the guidelines over recommendations on the treatment and surveillance of patients with HGAIN/AIN II/III. All three sets of guidelines are based on low level, outdated evidence originating from the 1980s and 1990s.

Loss of histone variant macroH2A2 expression associates with progression of anal neoplasm

Aims

The macroH2A histone variants are epigenetic marks for inactivated chromatin. In this study, we examined the expression of macroH2A2 in anal neoplasm from anal intraepithelial neoplasia (AIN) to anal squamous cell carcinoma (SCC).

Methods

AIN and anal SCC samples were analysed for macroH2A2 expression, HIV and human papilloma virus (HPV). The association of macroH2A2 expression with clinical grade, disease recurrence, overall survival and viral involvement was determined.

Results

macroH2A2 was expressed in normal squamous tissue and lower grade AIN (I and II). Expression was lost in 38% of high-grade AIN (III) and 71% of anal SCC (p=0.002). Patients with AIN with macroH2A2-negative lesions showed earlier recurrence than those with macroH2A2-positive neoplasm (p=0.017). With anal SCC, macroH2A2 loss was more prevalent in the HPV-negative tumours.

Conclusions

Loss of histone variant macroH2A2 expression is associated with the progression of anal neoplasm and can be used as a prognostic biomarker for high-grade AIN and SCC.

Local administration of granulocyte macrophage colony-stimulating factor induces local accumulation of dendritic cells and antigen-specific CD8+ T cells and enhances dendritic cell cross-presentation

Immunotherapy has emerged as a promising treatment strategy for the control of HPV-associated malignancies. Various therapeutic HPV vaccines have elicited potent antigen-specific CD8+ T cell mediated antitumor immune responses in preclinical models and are currently being tested in several clinical trials. Recent evidence indicates the importance of local immune activation, and higher number of immune cells in the site of lesion correlates with positive prognosis. Granulocyte macrophage colony-stimulating factor (GMCSF) has been reported to posses the ability to induce migration of antigen presentation cells and CD8+ T cells. Therefore, in the current study, we employ a combination of systemic therapeutic HPV DNA vaccination with local GMCSF application in the TC-1 tumor model. We show that intramuscular vaccination with CRT/E7 DNA followed by GMCSF intravaginal administration effectively controls cervicovaginal TC-1 tumors in mice. Furthermore, we observe an increase in the accumulation of E7-specific CD8+ T cells and dendritic cells in vaginal tumors following the combination treatment. In addition, we show that GMCSF induces activation and maturation in dendritic cells and promotes antigen cross-presentation. Our results support the clinical translation of the combination treatment of systemic therapeutic vaccination followed by local GMCSF administration as an effective strategy for tumor treatment.

Toll-like receptor agonist imiquimod facilitates antigen-specific CD8+ T-cell accumulation in the genital tract leading to tumor control through IFNγ

PURPOSE

Imiquimod is a Toll-like receptor 7 agonist used topically to treat external genital warts and basal cell carcinoma. We examined the combination of topical imiquimod with intramuscular administration of CRT/E7, a therapeutic human papillomavirus (HPV) vaccine comprised of a naked DNA vector expressing calreticulin fused to HPV16 E7.

EXPERIMENTAL DESIGN

Using an orthotopic HPV16 E6/E7(+) syngeneic tumor, TC-1, as a model of high-grade cervical/vaginal/vulvar intraepithelial neoplasia, we assessed if combining CRT/E7 vaccination with cervicovaginal deposition of imiquimod could result in synergistic activities promoting immune-mediated tumor clearance.

RESULTS

Imiquimod induced cervicovaginal accumulation of activated E7-specific CD8(+) T cells elicited by CRT/E7 vaccination. Recruitment was not dependent upon the specificity of the activated CD8(+) T cells, but was significantly reduced in mice lacking the IFNγ receptor. Intravaginal imiquimod deposition induced upregulation of CXCL9 and CXCL10 mRNA expression in the genital tract, which are produced in response to IFNγ receptor signaling and attract cells expressing their ligand, CXCR3. The T cells attracted by imiquimod to the cervicovaginal tract expressed CXCR3 as well as CD49a, an integrin involved in homing and retention of CD8(+) T cells at mucosal sites. Our results indicate that intramuscular CRT/E7 vaccination in conjunction with intravaginal imiquimod deposition recruits antigen-specific CXCR3(+) CD8(+) T cells to the genital tract.

CONCLUSIONS

Several therapeutic HPV vaccination clinical trials using a spectrum of DNA vaccines, including vaccination in concert with cervical imiquimod, are ongoing. Our study identifies a mechanism by which these strategies could provide therapeutic benefit. Our findings support accumulating evidence that manipulation of the tumor microenvironment can enhance the therapeutic efficacy of strategies that induce tumor-specific T cells.

Anal intraepithelial neoplasia: a single centre 19 year review

AIM

There is debate about whether the traditional three-tiered grading of anal intraepithelial neoplasia (AIN) should be replaced by a more reproducible two-tiered system. In this study, we review our experience with AIN to determine the most suitable classification system.

METHOD

We performed a retrospective review of all histological reports over a 19 year period. All specimens were graded on haemataloxin and eosin appearance and those with dysplasia had immunohistochemistry for p16 and Ki67 performed.

RESULTS

Cases included 25 condyloma acuminata, 11 dysplastic cases and 24 invasive squamous cell carcinomas. On review, 18 were classified as condyloma acuminata without dysplasia. Seven had AIN I, five had AIN II and six had AIN III when using a three-tiered system. All cases classified as dysplastic (n = 18) showed an increased proliferation index as measured by Ki67. p16 positivity was seen in all AIN III, two AIN II and none of the AIN I cases. Recurrence was not observed in any of the AIN I cases. Five of eleven AIN II and AIN III cases recurred or persisted at a similar, higher or lower grade. Both of the AIN II cases which recurred or persisted were p16 positive. None of the AIN II cases that were p16 negative recurred. Three of the p16-positive AIN III cases did not recur. None of the 18 AIN cases progressed to carcinoma.

CONCLUSION

The findings support the slow progression of AIN as described in the literature. In our small series, a two-tiered system with further subclassification of the traditional AIN II group using p16 appears to be clinically useful.

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.

Anal squamous intraepithelial neoplasia

Diagnosis, follow up, and treatment of anal intraepithelial neoplasia are complex and not standardized. This may be partly caused by poor communication of biopsy and cytology findings between pathologists and clinicians as a result of a disparate and confusing terminology used to classify these lesions. This article focuses on general aspects of epidemiology and on clarifying the current terminology of intraepithelial squamous neoplasia, its relationship with human papilloma virus infection, and the current methods that exist to diagnose and treat this condition.

The relationship between the cervical and anal HPV infection in women with cervical intraepithelial neoplasia

BACKGROUND

More than 90% of cases of anal cancers are caused by high-risk human papillomavirus (HR HPV) infection and a history of cervical intraepithelial neoplasia (CIN) is established as possible risk factor.

OBJECTIVES

To demonstrate relationship between anal and cervical HPV infection in women with different grades of CIN and microinvasive cervical cancer.

STUDY DESIGN

A total of 272 women were enrolled in the study. The study group included 172 women who underwent conization for high-grade CIN or microinvasive cervical cancer. The control group consisted of 100 women with non-neoplastic gynecologic diseases or biopsy-confirmed CIN 1. All participants completed a questionnaire detailing their medical history and sexual risk factors and were subjected to anal and cervical HPV genotyping using Cobas and Lynear array HPV test.

RESULTS

Cervical, anal, and concurrent cervical and anal HPV infections were detected in 82.6%, 48.3% and 42.4% of women in the study group, and in 28.0%, 26.0% and 8.0% of women in the control group, respectively. The prevalence of the HR HPV genotypes was higher in the study group and significantly increased with the severity of cervical lesion. Concurrent infections of the cervix and anus occurred 5.3-fold more often in the study group than in the control group. Any contact with the anus was the only significant risk factor for development of concurrent HPV infection.

CONCLUSIONS

Concurrent anal and cervical HR HPV infection was found in nearly half of women with CIN 2+. The dominant genotype found in both anatomical locations was HPV 16. Any frequency and any type of contact with the anus were shown as the most important risk factor for concurrent HPV infection.

Safe ablation of the anal mucosa and perianal skin in rats using Photodynamic Therapy--a promising approach for treating Anal Intraepithelial Neoplasia

BACKGROUND

Anal Intraepithelial Neoplasia (AIN), a pre-cursor of anal squamous carcinoma, is increasingly detected in individuals with impaired immune function. However, choices for effective, low morbidity treatment are limited. Photodynamic Therapy (PDT) is promising as it is known to ablate more proximal gastrointestinal mucosa with safe healing, without damage to underlying muscle. It can also ablate skin with safe healing and minimal scarring.

METHODS

Pharmacokinetics: Normal rats were sensitised with 200mg/kg 5-aminolaevulinic acid (ALA) and killed 1-8h later. Anal tissues were examined by fluorescence microscopy to quantify the concentration of PPIX (protoporphyrin IX, the active derivative of ALA) in anal mucosa and in the underlying sphincter. PDT: Normal rats were sensitised similarly 3h later, laser light (635 nm) was delivered. Anal canal: 50-150 J/cm using 1cm diffuser fibre; for peri-anal skin, 50-200 J/cm(2), using microlens fibre. In each group, 2 rats were killed 3, 7, 14 and 28 days later and the anal region removed for histological examination.

RESULTS

Pharmacokinetics: Peak concentration of PPIX in mucosa was at 3h, peak ratio mucosa: muscle, 6, seen at same time. PDT. Anal canal 50 J/cm: complete mucosal ablation by 3 days, complete regeneration by 28 days. Higher energies caused muscle damage with scarring. Peri-anal skin: 200 J/cm(2); complete ablation of skin, including appendages, complete healing by 28 days. Minimal effect with lower energy.

CONCLUSION

ALA-PDT can ablate anal mucosa and peri-anal skin with safe healing and no underlying damage. However, over treatment can damage the sphincters. This technique is ready to undergo clinical trials.

Anal intraepithelial neoplasia: review and recommendations for screening and management

Anal cancer is a rare malignancy of the distal gastrointestinal tract, often associated with human papillomavirus, the most common sexually transmitted infection worldwide. Currently available screening methods for anal intraepithelial neoplasia, a precursor for anal cancer, combine anal Papanicolaou cytology and high resolution anoscopy with biopsy of suspicious lesions. Significant barriers to establishing anal cancer screening programmes include the small number of healthcare professionals performing high resolution anoscopy and the lack of data showing that anal cancer screening can reduce morbidity and mortality related to anal carcinoma. Despite several controversies surrounding anal cancer screening, the rising incidence of this disease in some groups supports routine screening programmes in high-risk populations, especially in HIV-positive men who have sex with men.

This review outlines the epidemiology of anal intraepithelial neoplasia and anal cancer and summarizes issues related to the introduction of anal cancer screening programmes.

Anal intraepithelial lesions in women with human papillomavirus-related disease

OBJECTIVE

This study aimed to determine the prevalence of anal intraepithelial lesions in women with histologic diagnosis of intraepithelial lesions of the lower genital tract.

MATERIALS AND METHODS

This was a cross-sectional study conducted at the Lower Genital Tract and Colposcopy Unit of Hospital de Clínicas "José de San Martín," University of Buenos Aires, Argentina. A total of 481 women with histologically confirmed low-grade and high-grade cervical, vaginal, or vulvar intraepithelial lesions were evaluated between 2005 and 2011. They were referred for cytologic samples and examination with high-resolution anoscopy. We obtained biopsy specimens of any suspicious colposcopic images.

RESULTS

Of a total of 481 patients, 404 (84%) were immunocompetent, 31 (6.4%) were HIV+, and 46 (9.6%) had other causes of immunosuppression. Moreover, of the 481 patients, 134 (27.86%) had anal intraepithelial neoplasia (AIN); 28 (5.82%) had high-grade AIN and 106 (22%) had low-grade AIN. Women with high-grade cervical intraepithelial neoplasia (CIN 2, 3) had 2 times the odds of developing AIN compared with women with low-grade CIN (CIN 1) (odds ratio = 1.91, 95% confidence interval = 1.1-3.6). Regarding localization, we found statistically significant difference between the frequency of vulvar and anal lesions. Women with vulvar condylomata and vulvar intraepithelial neoplasia (VIN) may be more likely to develop AIN.

CONCLUSIONS

Immunocompetent women with CIN, vaginal intraepithelial neoplasia, or VIN may also present high-grade or low-grade anal intraepithelial lesions so we should consider AIN as part of multicentric disease of the lower genital tract. Cervical intraepithelial neoplasia, VIN, condyloma accuminatta, and vaginal intraepithelial neoplasia could be warning signs of anal intraepithelial lesions.

Annual cost of hospitalization, inpatient rehabilitation and sick leave of anal cancer in Germany

OBJECTIVE

Literature on the economic burden of anal cancer in Germany is scarce. About 84% of these cancers are associated with human papillomavirus infection. This study, therefore, aimed to assess the annual costs of human papillomavirus-related anal cancer incurred by hospitalization, inpatient rehabilitation, and sick leave in 2008 in Germany.

METHODS

A cross-sectional retrospective analysis of five German databases covering hospital treatment, inpatient rehabilitation, and sick leave in 2008 was performed. All hospital, inpatient rehabilitation, and sick leave cases due to anal cancer in 2008 were analyzed. Associated numbers of anal cancer hospitalizations, healthcare resource use, and costs were identified and extracted using the ICD-10 code C21 as the main diagnosis. The annual cost of human papillomavirus-related anal cancer was estimated based on the percentage of anal cancer likely to be attributable to human papillomavirus.

RESULTS

In 2008, there were 5774 hospitalizations (39% males, 61% females), 517 inpatient rehabilitations, and 897 sick leaves due to anal cancer representing costs of €34.11 million. The estimated annual costs associated with human papillomavirus-related anal cancer were €28.72 million, mainly attributed to females (62%). Direct costs accounted for 90% (86% for hospital treatment, 4% for inpatient rehabilitation) and indirect costs due to sick leave accounted for 10% of human papillomavirus-related costs.

CONCLUSIONS

The economic burden of human papillomavirus-related anal cancer in 2008 in Germany is under-estimated, since costs incurred by outpatient management, outpatient chemotherapy, long-term care, premature retirement, and premature death were not included. However, this study is the first analysis to investigate the economic burden of anal cancer in Germany. The estimated annual costs of human papillomavirus-related anal cancer contribute to a significant economic burden in Germany and should be considered when assessing health and economic benefits of human papillomavirus vaccination in both genders.

Human papillomavirus-related genital disease in the immunocompromised host: Part II

Human papillomavirus is responsible for common condyloma acuminata and a number of premalignant and malignant anogenital lesions. The immunocompromised population is at particular risk because of a higher incidence of malignant transformation. Lesions in this population may prove refractory to standard treatment. This is part II of a two-part review that will discuss the treatment of condyloma acuminata and vaginal, vulvar, penile, and anal intraepithelial neoplasias. This article will provide an updated review of available treatments, with a focus on recent advances and the challenges faced in successfully treating human papillomavirus lesions in the immunocompromised host.

Do not forget to examine the genitals: a case of anal cancer and anogenital intraepithelial neoplasia in an immunocompetent man

A 46-year-old Caucasian heterosexual male was referred to a dedicated AIN clinic from colorectal multidisciplinary meeting (MDM) with AIN 3 following complete resection of anal squamous cell carcinoma (SCC). On further questioning, he revealed that he also had a lesion on his penis. Histology of the penile lesion demonstrated full thickness penile intraepithelial neoplasia (PIN 3). This case illustrates the importance of thorough genital examination in patients found to have one genital pathology.

Fluorescence diagnostics as a guide for demarcation and biopsy of suspected anal cancer

BACKGROUND

Malignant epithelial tumors of the perianal skin are relatively rare however show high recurrence rates. A preoperative precise diagnosis and demarcation of the involved cancerous skin remains challenging but is worthwhile to minimize tissue defects and possible limitations of quality of life.

OBJECTIVES

To show the use of fluorescence diagnostics (FD) in the management of chronic perianal disease.

METHODS

FD was performed using methylaminolevulinate (MAL) for three hours topically followed by visualization with blue light (405 nm).

RESULTS

We report on two patients in whom FD helped to demarcate the involved tissue or to direct biopsy to ascertain the final diagnosis. In one patient with a history of Bowen's disease and recurrent anal carcinoma, biopsy showed extramammary Paget's disease and thus was treated by surgical anoplasty. The other patient had a history of chronic anal eczema, and FD-directed biopsy could exclude suspected malignancy so that the anal eczema was treated by local therapy.

CONCLUSIONS

FD is a non-invasive technique which can be used in the perianal region in order to delineate pathologic processes which may reduce the number of surgical interventions.

Four decades of anal cancer in Tasmania, Australia: what do the case data tell us?

Background Anal cancer is a rare cancer analogous to cervical cancer, largely caused by exposure to oncogenic human papillomavirus. We have sought to study this disease in the epidemiologically distinct population of Tasmania. Methods: Medical records at all tertiary and secondary referral centres in Tasmania were audited for records with corresponding International Classification of Diseases (ICD)-10 codes. Statistical significances of trends were evaluated using Fisher’s exact test, logistic regression or linear regression. Results: Of ~1350 screening records, 170 cases of anal cancer were found with patient presentation during 1973–2010, corresponding to 132 patients. This cohort was mostly female (66.7%), with squamous cell histology (81.8%) and anal canal primaries (72.0%). Most cases were detected at Stage II or below and the majority remained disease-free after treatment. Relatively few cases had documentation of typical risk factors for anal cancer, such as HIV seropositivity, a history of cancer or smoking. After 2000, there was a trend towards a lower stage at presentation, correlating with an increased 5-year survival. After 2000, no anal margin tumours presented beyond Stage II; nearly half were detected in situ and none were fatal. For anal canal tumours, there was virtually no change in the mean stage at detection or in survival. Conclusion: This is the first case series of anal cancer in Tasmania. We find that in many ways, including symptoms and pathology at presentation, epidemiology is typical. However, our cohort is distinct in its paucity of known risk groups, including HIV-positive people, those with a history of cancer and smokers.

Association between genital intraepithelial lesions and anal squamous intraepithelial lesions in HIV-negative women

OBJECTIVE

The objective of the study was to evaluate the risk of anal squamous intraepithelial lesions (ASILs) in immunocompetent women with genital squamous intraepithelial lesions (GSILs).

STUDY DESIGN

This was a cross-sectional study that included 260 immunocompetent women divided into 2 study groups: 1 group included 184 women diagnosed with GSIL by genital colposcopy and biopsy, and the other included 76 controls. All subjects were submitted to anoscopy followed by a biopsy if pertinent.

RESULTS

Of 184 GSIL women, 32 (17.4%) had ASIL (P<.001). The risk of ASIL was 13.1 times greater for GSIL women when there were 3 or 4 genital sites involved. All cases of high-grade ASIL were found in women with cervical GSILs. Among risk factors, anal intercourse without a condom demonstrated an important association with ASIL (prevalence ratio adjusted for age=2.6).

CONCLUSION

There seems to be a strong association between ASIL and multicentric GSIL. Another factor related to ASIL was the practice of unprotected anal intercourse.

[Early detection of anal intraepithelial neoplasia in high-risk patients]

The incidence of anal squamous cell carcinoma has increased alarmingly, particularly in high-risk groups such as men who have sex with men and immunosuppressed patients. Infection with an oncogenic strain of the human papillomavirus in the anal canal or perianal skin leads to anal intraepithelial neoplasias (AIN), progressive dysplastic intraepithelial lesions that are the precursors of anal squamous cell carcinoma. AIN can be diagnosed through cytological screening and biopsy guided by high-resolution anoscopy and can be treated using a range of procedures in an effort to prevent progression to invasive anal carcinoma. Given the recent advances in the understanding of this disease, and the increasing calls from experts for the establishment of screening programs to identify AIN, we review current knowledge on the condition, its diagnosis, and treatment from the point of view of dermatology.

What should we do about anal condyloma and anal intraepithelial neoplasia? Results of a survey

AIM

There is a lack of standardization regarding diagnosis, treatment and surveillance of patients with anal HPV infection.

METHOD

An Internet-based survey was sent to members of international, surgical and dermatological societies. Answers were obtained from 1017 dermatologists and 393 colorectal surgeons (n = 1410).

RESULTS

More dermatologists than surgeons provided noninvasive treatment of anal condyloma with 5% imiquimod (80.4 vs 28.2%; P < 0.001), whereas the situation was reversed for surgical excision (56.8 vs 91.3%; P < 0.001). To detect dysplastic lesions, 42.0% of surgeons used acetic acid only, 23.2% used this in combination with high-resolution anoscopy and 19.5% applied intra-anal cytological smears. Likewise, 64.6% of dermatologists applied acetic acid only, 16.5% combined acetic acid with high-resolution anoscopy and 30.2% performed intra-anal cytological smears (all P < 0.001 compared with surgeons). The therapy for anal intraepithelial lesions was not influenced by the grade of dysplasia, but it was by immune status.

CONCLUSION

There were significant differences in practice between colorectal surgeons and dermatologists. These findings highlight the need for international and cross-disciplinary clinical guidelines.

Economic burden of HPV-related cancers in France

Human papillomavirus (HPV) infection is associated with a range of diseases and cancers at different anatomical sites. In addition to its role as a necessary cause of cervical cancer, HPV is also associated with cancers of the vulva, vagina, anus, penis, head and neck. With the exception of cervical cancer, however, very few data are available on the economic burden of HPV-associated cancers. We assessed the annual costs associated with management of HPV-related cancers in France from the healthcare payers' perspective. We used data from studies that employed similar methodologies to estimate the costs during 2006 for cervical cancer, vulvar and vaginal cancers, anal cancer, and penile cancer, and during 2007 for head and neck cancers. Data on hospital-management costs for cancer were derived from the French national hospital database. The costs of outpatient care and daily allowance costs were estimated using data from the French National Institute of Cancer report for 2007. The costs for HPV-related cancers were estimated according to the percentage of each cancer type attributable to HPV infection. The estimated total costs associated with HPV-related cancers in France were €239.7 million. The overall costs in men were €107.2 million, driven mainly by head and neck cancers (€94.6 million). The total costs in women were €132.5 million, due mainly to invasive cervical cancer (€83.9 million). The costs associated with HPV-related cancers are important to consider when evaluating the overall benefits of HPV vaccination in males and females.

Description of a pilot anal pap smear screening program among individuals attending a Veteran's Affairs HIV clinic

Despite the higher risk of anal cancer among HIV-infected individuals currently there are no national or international guidelines for anal dysplasia screening. We assessed acceptance and feasibility of screening for anal intraepithelial neoplasia (AIN), the rate of abnormalities, and relationship between the presence of AIN and a history of receptive anal intercourse. Eighty-two percent of HIV-patients approached during routine clinic visit agreed to participate in the study with anal Pap smear collection; 53% had abnormal cytology results and among those undergoing high-resolution anoscopy with biopsy, 55% had high-grade AIN, including 2 cases of carcinoma in situ. Anal cytology was well accepted and it was feasible to be incorporated into HIV primary care practice. Abnormal cytology was not significantly associated with history of anal intercourse (p = 0.767). The high rate of abnormal results reinforces the need for further evaluation of the role of systematic anal Pap smear screening for HIV patients.

[Anal intraepithelial neoplasia and anal carcinoma: an increasing problem in HIV patients]

Anal dysplasia is common in HIV patients, especially in HIV-positive men having sex with men (MSM). High-grade anal dysplasia can progress to invasive anal cancer. As in cervical carcinoma, there is a cause and effect relationship between anal cancer and human papillomavirus (HPV) infection, especially with high-risk types such as HPV16. Several experts have recommended screening programs for anal cancer, including anal cytology along the lines of the Pap smear in women. Such screenings should only be performed if pathological findings result in further diagnostic steps and, if necessary, appropriate treatment. Clinical inspection, lesion biopsy, and treatment of anal dysplasia are performed under high-resolution anoscopy. Anal cancer is divided into cancer of the anal margin and cancer of the anal canal. This classification is important because of the difference in treatment regimens. Early cancer of the anal margin is excised akin to squamous cell cancer of the exposed skin, whereas cancer of the anal canal is treated by radiochemotherapy. HIV-positive and HIV-negative patients have similar response rates to combined radiochemotherapy. However, side effects, especially acute post-irradiation skin toxicity, early local recurrences, and abdominoperineal rectal excision are more common in HIV-positive patients. Physicians working in the field of HIV/AIDS should regularly screen their patients for the presence of anal dysplasia and anal cancer. Basic diagnostic workup includes clinical inspection of the perianal area, digital rectal examination, and anal cytology.

Human papillomavirus genotypes in anal intraepithelial neoplasia and anal carcinoma as detected in tissue biopsies

Human papillomavirus (HPV) infection strongly correlates with the development of anal intraepithelial neoplasias and carcinomas; however, few studies have characterized the distribution of the specific subtypes of the virus in the varying grades of dysplasia. This report characterizes the distribution of HPV 16/18 in surgical specimens with anal intraepithelial neoplasia (AIN) I-III and histological variants of anal carcinoma. A total of 111 anal surgical specimens with no dysplasia (10), AIN I-III (53), and anal carcinomas (48) were evaluated for the presence of high-risk HPV infection and subtyped by nested PCR or the Invader Assay. High-risk virus types were detected in progressively greater number of anal intraepithelial lesions from 56% in low grade to 88% in high grade. Type 16 was the prevalent subtype and was noted in 28% of low grade and 68% of high-grade lesions. Moderate dysplasias showed type 16 in 20%, a prevalence similar to that in low-grade lesions. The non-16/18 subtypes of the virus predominated and were present in 50% of the cases. Most (89%) squamous carcinomas were associated with high-risk viruses, 68% with type 16, a prevalence similar to that noted in high-grade dysplasia. Non-16/18 subtypes were encountered more frequently in squamous carcinomas from immunodeficient individuals (57% cases) as compared with immunocompetent individuals (18% cases). The similarity in the prevalence of type 16 in high-grade dysplasia and squamous carcinomas suggests that anal intraepithelial lesion III is the true precursor of squamous carcinoma and warrants aggressive management. Anal intraepithelial lesions II showed a virus distribution that was similar to low-grade dysplasia. In addition, a subset of these that were associated with type 16 or 18 showed progression, whereas those associated with non-16/18 subtypes regressed, thereby raising the possibility of conservative management for these lesions.

Efficacy of trichloroacetic acid in the treatment of anal intraepithelial neoplasia in HIV-positive and HIV-negative men who have sex with men

BACKGROUND

Anal intraepithelial neoplasia (AIN), particularly AIN 3 is a precursor to anal cancer. Most cases of AIN are intraanal, but few treatments for intraanal AIN are currently available. Topical 85% trichloroacetic acid (TCA) is an inexpensive method used to treat perianal condyloma, a form of AIN 1, but its efficacy to treat intraanal AIN as first-line therapy is unknown.

METHODS

Retrospective review of medical records was performed for all patients with AIN treated at the University of California San Francisco Anal Neoplasia Clinic with TCA as the first-line therapy from January 2000 to December 2004. Clearance was defined as the absence of AIN confirmed by high-resolution anoscopy and cytology after up to 4 TCA treatments.

RESULTS

Thirty-five HIV-positive men and 19 HIV-negative men met the enrollment criteria. In multivariate analysis, greater clearance was seen in patients 41-48 years of age versus >49 years [odds ratio (OR): 8.4, confidence interval (CI): 1.1 to 94, P: 0.04]. Among HIV-positive men, those with 2 or fewer lesions showed greater clearance (OR: 14.3, CI: 1.5 to 662, P: 0.01). 32% of patients with AIN 2/3 cleared to no lesions. On a per lesion basis, 73% of AIN 1 and 71% AIN 2/3 cleared to no lesion or AIN 1 or less, respectively.

CONCLUSIONS

Topical 85% TCA was safe and well tolerated. It was more effective in younger patients and among HIV-positive patients, those with 2 or fewer lesions. A high proportion of AIN 2/3 lesions responded to TCA treatment.