The etiology and epidemiology of anal cancer

HIV-Associated Anal Cancer

Anal cancer, despite being a rare malignancy, is increasing in incidence, accounting for 0.5% of all new cancer cases in the United States, with rate of new cases being 1.9 per 100,000 men and women. It is common in immunocompromised individuals, especially those with malignancy, human immunodeficiency virus (HIV) and human papillomavirus (HPV) infection. Despite similar treatment of anal cancer in both HIV-positive and negative patients, guidelines for prevention and treatment of therapy-related side effects are rarely studied. While these patients have a better prognosis on HAART, limited guidelines exist regarding appropriate therapy. There is a common link between HPV and HIV and the transmission of one is associated with increased risk of transmission of the other. HPV vaccine which is known to prevent high-grade cervical intraepithelial neoplasia is thought to also decrease the incidence of anal intraepithelial neoplasia. The association of HPV vaccine in the prevention of anal cancer in high-risk groups with HIV is a scarcely studied subject that requires further research.

Survival and Operative Outcomes After Salvage Surgery for Recurrent or Persistent Anal Cancer

Anal squamous cell carcinoma (SCC) is a relatively rare cancer comprising less than 2.5% of all gastrointestinal malignancies. The standard treatment for anal SCC is primary chemoradiation therapy which can result in complete regression. After successful treatment, the 5-year survival is approximately 80%. However, up to 30% of patients experience recurrent persistent or recurrent disease. The role of surgery in the treatment of anal cancer, therefore, is limited to the management of recurrent or persistent disease with abdominoperineal resection and/or en bloc adjacent organ excision. Salvage surgery after irradiated anal cancer can be technically demanding in terms of acquisition of oncologically safe surgical margins and minimization of postoperative morbidity. In addition, 5-year survival outcomes after salvage resection have been reported to vary from 23% to 69%. Positive resection margins are generally regarded as the important risk factor associated with poor survival outcome. Perineal wound complications are the most common major postoperative morbidity. Because of the challenges of primary wound closure after salvage abdominoperineal resection, myocutaneous flap reconstruction has been performed to reduce the severity of perianal would complications. We, therefore, descriptively reviewed contemporary published evidence describing the treatment and outcomes after salvage surgery for persistent or recurrent anal SCC.

Management of anal intraepithelial neoplasia and anal squamous cell carcinoma at a tertiary referral centre with a dedicated infectious diseases unit: an 18-year review

INTRODUCTION

Anal squamous cell carcinoma (ASCC) is a rare malignancy with rising incidence rates. Risk factors include human immunodeficiency virus (HIV) infection, high-risk sexual activity and HPV-related genitourinary dysplasia/neoplasia. There is an overlap between high-risk patients and those attending HIV Medicine/Sexual Health (HMSH) services. We hypothesised that HMSH involvement may facilitate earlier referral to colorectal surgeons, with better outcomes.

METHODS

Retrospective review of all ASCC and anal intraepithelial neoplasia (AIN) treated at a tertiary-referral hospital with a dedicated HMSH clinic between 2000 and 2018. Comparative analysis was performed of demographics, management and outcomes between HMSH and non-HMSH patients.

RESULTS

One hundred and nine patients had anal pathology, eighty-five with ASCC (78%) and twenty-four with AIN (22%). Seventy (64%) were male. Median (range) age at ASCC diagnosis was 51 years (26-88). Thirty-six percent of all patients attended HMSH services, 28% were HIV positive, and 41% of males were men-who-have-sex-with-men (MSM). Eighty-one ASCC patients (97.5%) were treated with curative intent. Sixty-seven (80%) had primary chemoradiation therapy. Fifteen (17.5%) had primary surgical excision. Twelve (14%) developed recurrent disease. Ultimately, seven required salvage APR. Overall 3-year survival (3YS) was 76%. HMSH patients were significantly younger at ASCC diagnosis (p < 0.001), with a higher prevalence of HIV, HPV and MSM. HMSH attenders also tended to be diagnosed at earlier stages, were less likely to develop recurrence and achieved better overall outcomes, with a superior overall 3YS than non-HMSH patients (92% vs 72%, p = 0.037).

CONCLUSION

ASCC incidence is increasing worldwide. The HMSH cohort has emerged as a distinct subpopulation of younger, high-risk, male patients. Collaboration between HMSH and colorectal surgeons offers an opportunity for risk reduction strategies and earlier intervention.

Investigating epidemiologic trends and the geographic distribution of patients with anal squamous cell carcinoma throughout Canada

Background

Anal cancer is a rare disease, constituting 0.5% of new cancer cases in the United States. The most common subtype is squamous cell carcinoma (scc). Studies in several developed nations have reported on an increasing incidence of anal cancer in recent decades, and various risk factors pertaining to the pathogenesis of the disease have been identified, including infection with the human papillomavirus, tobacco use, and immunosuppression. The epidemiology and distribution of anal scc throughout Canada remain poorly understood, however.

Methods

Using 3 population-based cancer registries, a retrospective analysis of demographic data across Canada for 1992-2010 was performed. The incidence and mortality for anal scc was examined at the levels of provinces, cities, and the forward sortation area (FSA) component (first 3 characters) of postal codes.

Results

During 1992-2010, 3720 individuals were diagnosed with anal scc in Canada; 64% were women. The overall national incidence rate was 6.3 cases per million population per year, with an average age at diagnosis of 60.4 years. The incidence increased over time, with significantly higher incidence rates documented in British Columbia and Nova Scotia (9.3 cases per million population each). Closer examination revealed clustering of cases in various urban centres and self-identified lgbtq communities in Toronto, Montreal, and Vancouver.

Discussion

This study provides, for the first time, a comprehensive analysis of the burden of anal scc in Canada, identifying susceptible populations and shedding light onto novel avenues of research to lower the incidence of anal cancer throughout the country.

Incidence and survival of rare cancers in the US and Europe

Geographical variability of cancer burden was almost exclusively estimated for common cancers. Since rare cancers (RC) have become an area of priority for basic and clinical research and public health organizations, this paper provides, using a common methodology, a detailed comparison of incidence and survival for RC in the US and Europe. We estimated incidence and net survival of 199 malignant RC from data of 2 580 000 patients collected by 18 US-SEER and 94 European registries, diagnosed within the most recent common period 2000-2007. RC were defined according to the criterion of crude annual incidence rates <6/100 000. In total, 196 RC were classified as rare in both populations. Of these, 43 had incidence rates significantly different by at least 0.2 per 100 000:34 higher in the US and 9 higher in Europe. Five-year net survival for all RC combined significantly differed: 54% in the US and 48% in Europe. Survival for 62 RC was significantly higher in the US vs 6 higher in Europe. Differences were not concentrated in a particular cancer family, and were mostly relevant for cases diagnosed >65+ years of age. Use of standardized methods evidenced that incidence and survival rate of majority of RC were higher in the United States compared to Europe. Possible reasons for such differences, requiring further studies, include distribution of risk factors, ability to diagnose RC, different registration practices, and use of updated International Classification of Diseases for Oncology.

Anal human papillomavirus among men who have sex with men in three metropolitan cities in southern China: implications for HPV vaccination

INTRODUCTION

Men who have sex with men (MSM), especially those infected with human immunodeficiency virus (HIV), are at disproportionate risk for human papillomavirus (HPV) infection. Data about anal HPV prevalence among MSM in southern China are limited.

METHODS

MSM were recruited between January 1 and August 31, 2017 in three metropolitan cities: Guangzhou, Shenzhen and Wuxi. A self-completed tablet-based questionnaire was used to collect information about socio-demographic/sexual behavioral characteristics, history of sexually transmitted infections (STIs) and recreational drug use. An anal brush was used to collect exfoliated cells for HPV DNA testing and genotyping, and a blood sample was taken for HIV testing. Penile/anal warts were checked by a clinician.

RESULTS

A total of 536 MSM were enrolled, including 39 HIV-positive and 497 HIV-negative individuals. Compared with HIV-negative MSM, prevalence of any HPV genotype (79.5% vs 46.7%), any high-risk genotype (64.1% vs 36.6%) and any nonavalent vaccine-preventable genotype (53.9% vs 31.6%) was significantly higher in HIV-positive MSM, with all P < 0.01. HIV infection (adjusted odds ratio [AOR], 4.28; 95% confidence interval [CI], 1.87-9.80), using recreational drugs (AOR, 1.87; 95% CI, 1.22-2.87), having ≥ 3 years of sexual experience (AOR, 1.52; 95% CI, 1.01-2.28), having ≥ 6 lifetime male partners (AOR, 1.92; 95% CI, 1.29-2.86), and engaging receptive anal intercourse (AOR, 2.30; 95% CI, 1.48-3.57) were associated with higher anal HPV prevalence. Any HPV prevalence increased with age, from 24.5% at < 20 years to 55.8% at ≥ 40 years.

CONCLUSIONS

Anal HPV prevalence was high among MSM in southern China, significantly associated with HIV status and sexual experience. HPV prevalence increased with age among MSM. A targeted HPV vaccination program for teenage MSM might be necessary. Our findings will inform targeted HPV modelling among MSM in China.

Natural History of Anal Squamous Intraepithelial Lesions in HIV-Positive Men with Normal Baseline Cytology

The natural history of squamous intraepithelial lesions (SILs) in the anal canal of HIV-infected men is incompletely understood. We assessed the incidence and factors associated with SIL and invasive anal squamous cell carcinoma (IASCC) among HIV-infected men with normal cytology at baseline. We performed a single-center prospective cohort study [men who have sex with men (MSM) and men who have sex with women (MSW)]. The incidence of anal canal SIL (low grade and high grade) and IASCC were estimated and predictive factors analyzed. The study population comprised 297 HIV-infected men with a normal cytology result and no anal human papillomavirus (HPV)-related diseases. Of these, 251 (85%) had at least one evaluable set of cytology data during follow-up (172 MSM, 79 MSW). The median follow-up time was 4 years. The cumulative incidence of SIL was 43% (107/251): 52% in MSM (90/172) and 22% in MSW (17/79), p < 0.0001. The incidence rate of SILs was 109 (95% confidence interval = 90-132) per 1000 person-years: 142 in MSM and 49 in MSW, p < 0.0001. HPV infection, receiving antiretroviral treatment (ART), and being MSM were independently associated risk factors. The incidence of IASCC was 0.15 per 1000 person-years among MSM and 0 in MSW. HIV-infected men, both MSM and MSW, are at high risk of developing SIL despite having a normal anal cytology at baseline. The incidence of anal canal SIL was higher among MSM, but was also remarkable among MSW. Independent risk factors associated with SIL were being HIV-infected MSM at high risk for acquisition of STIs, time on ART, and HPV infection.

Premalignant and Malignant Perianal Lesions

Anal cancer is a heterogeneous and rare disease process that accounts for ∼1.5% of all gastrointestinal tract malignancies. The perianal skin plays host to a variety of different premalignant and malignant lesions, all with variable histology, treatment options, and prognosis. Anal cancers in general are notorious for having a delayed or missed diagnosis leading to treatment delays and may have an impact on survival. This delay is in part due to the nonspecific symptomatology and also improper physical examination of the sensitive and anatomically complex perianal region and anal canal. This article examines the various types of perianal cancers and their precursor lesions and will explore treatment options as well as outcomes and prognosis.

A systematic review of outcomes after salvage abdominoperineal resection for persistent or recurrent anal squamous cell cancer

AIM

Up to 30% of patients with squamous cell cancer of the anus (SCCA) will require a salvage abdominoperineal resection (APR) for either persistent or recurrent disease. The objective of this study was to assess cancer-related outcomes in patients with (i) persistent or (ii) recurrent SCCA.

METHOD

Embase and MEDLINE were searched. Publications were included if they assessed overall survival (OS), disease-free survival (DFS) and locoregional recurrence or metastatic disease after salvage APR for persistent or recurrent SCCA.

RESULTS

A total of 28 retrospective case series (study size ranged from nine to 111) met our inclusion criteria. The median time to salvage APR was 2.6 months [interquartile range (IQR) 2.6-5.0 months, six studies] for persistent disease and 27.6 months (IQR 15.0-32.7 months, five studies) for recurrent disease. The median 5-year OS from the time of salvage APR was 45.0% (IQR 32.0%-52.3%, 10 studies) for persistent disease and 51.0% (IQR 36.0%-60.9%, 11 studies) for recurrent disease. The median 5-year DFS following salvage APR was 44.0% (IQR 29.5%-53.0%, 10 studies) for all patients. Following salvage APR, the median locoregional recurrence rate was 23.5% (IQR 15.8%- 46.9%, 19 studies) and 9.0% (IQR 6.4%-13.3%, 16 studies) of patients developed metastatic disease after salvage APR.

CONCLUSION

Our review characterizes the best evidence for outcomes following salvage APR for patients with persistent or recurrent SCCA. The evidence is limited by the quality of included studies, as many were single centre case series.

So Now My Patient Has Squamous Cell Cancer: Diagnosis, Staging, and Treatment of Squamous Cell Carcinoma of the Anal Canal and Anal Margin

Squamous cell carcinomas of the anal canal and the anal margin are rare malignancies that are increasing in incidence. Patients with these tumors often experience delayed treatment due to delay in diagnosis or misdiagnosis of the condition. Distinguishing between anal canal and anal margin tumors has implications for staging and treatment. Chemoradiation therapy is the mainstay of treatment for anal canal squamous cell, with abdominoperineal resection reserved for salvage treatment in cases of persistent or recurrent disease. Early anal margin squamous cell carcinoma can be treated with wide local excision, but more advanced tumors require a combination of chemoradiation therapy and surgical excision.

Ability to detect high-grade squamous anal intraepithelial lesions at high resolution anoscopy improves over time

Background Anal cancer is increasing in incidence, has very high rates in specific populations and shares many similarities with cervical cancer. High-grade squamous intraepithelial lesions (HSIL) are regarded as precursors to anal cancer. High resolution anoscopy (HRA), which is derived from colposcopy, is the only currently available tool that can identify areas of the anal canal for targeted biopsy and identification of HSIL.

METHODS

This study investigated the ability over a period of time of a single anoscopist to identify and adequately biopsy HSIL, correlating with contemporary anal cytological findings.

RESULTS

Four hundred paired cytology and histology samples collected from 283 patients over a 7-year period from 2004 to 2010 were compared. There was a significant increase in HSIL detection rates when anal squamous cells of undetermined significance (ASC-US; 38.6-66.0%) or low-grade squamous intra-epithelial lesion (38.8-68.3%) were taken as cut-off points (P<0.001 for both). Detection rates did not change significantly when atypical squamous cells-cannot exclude HSIL (ASC-H) or a higher grade lesion (70-76.6%) was taken as the cut-off point.

CONCLUSIONS

The increase in ability to detect histological HSIL over time and with increasing experience has the potential to impact on delivery of clinical services and the interpretation of clinical trial data. Further studies are required to determine the extent of this effect on other clinicians practising HRA.

Argon plasma versus electrofulguration in the treatment of anal and perianal condylomata acuminata in patients with acquired immunodeficiency virus

Purpose:

To compare the effectiveness of anal and perianal condylomata treatment using argon plasma and electrofulguration.

Methods:

From January 2013 to April 2014, 37 patients with anal and perianal condylomata, who had been diagnosed through proctological examination, oncotic cytology, polymerase chain reaction (PCR) and histology, underwent treatment with argon plasma and electrofulguration. The perianal and anal regions were divided into two semicircles. Each semicircle was treated using one of the methods by means of simple randomization. Therapeutic sessions were repeated until all clinical signs of infection by HPV were eliminated. The patients were evaluated according to several variables like the genotype of HPV, HIV infection, oncological potential per genotype, oncotic cytology and histology.

Results:

Among all the variables studied, only immunosuppression due to HIV influenced the results, specifically when the fulguration method was used. There was no significant difference in effectiveness between argon and fulguration based on lesion relapse (p > 0.05). However, among HIV-positive patients, fulguration presented worse results, with a significant difference (p = 0.01).

Conclusion:

Regarding treatment of anal and perianal condylomata acuminata, comparison between applying fulguration and argon demonstrated that these methods were equivalent, but use of fulguration presented more relapses among HIV-positive patients.

Surgical excision alone for stage T1 anal verge cancers in people living with HIV

INTRODUCTION

Anal cancer accounts for a small percentage of colorectal malignancies. Early stage (T1N0M0) cancers of the anal verge have been treated with local surgical excision alone in individuals without human immunodeficiency virus (HIV) infection. The risk of anal cancer is higher in people living with HIV (PLWH). We present results of the outcomes of T1 anal verge cancers treated by local excision only in a series of PLWH.

METHODS

Demographic and clinicopathological data was prospectively collected from all HIV positive individuals with anal cancer, treated between 1986 and 2015. The date from anal cancer diagnosis until the date of the last follow up were collected.

RESULTS

Fifteen patients had T1N0M0 cancer of the anal verge from a total of 92 patients with HIV-associated anal cancer. The mean age was 49 years (range 36-57). The average age of HIV diagnosis was 35 years (range 19-48) and four patients had a diagnosis of AIDS prior to the diagnosis of anal cancer. All patients were surgically managed with complete local excision of the tumour. There were no complications or need for any adjuvant therapy. No patients have relapsed and at a median follow up of 4 years (range 3-15), the overall survival was 100%.

CONCLUSION

Surgical resection for early stage anal verge cancers is an effective strategy in PLWH. Increasing awareness of anal cancer and anoscopy surveillance in PLWH will hopefully continue to identify anal cancers at an early stage that are amenable to minimally invasive surgical management.

Tumours and inflammatory lesions of the anal canal and perianal skin revisited: an update and practical approach

Tumours of the anal and perianal region are relatively rare, and clinically often interpreted as innocuous lesions, leading to frequent delays in diagnosis and adequate treatment. Although squamous cell neoplasia represents the most common entity encountered in this anatomically complex area, many conditions, both neoplastic and inflammatory, may occur. Adding to the challenge of correct diagnosis and patient management, recent years have seen major updates in the terminology of squamous cell neoplasia, created to reflect advances in our understanding of the role of human papilloma virus and unify previous terminologies used for different sites in the anogenital tract. However, squamous cell neoplasia in the anal canal and perianal region may differ in terms of histology, biological behaviour, staging and treatment. The aim of this review is to present an overview of neoplastic and non-neoplastic lesions that may be seen in this area, an update on important developments and terminology, potential pitfalls that may be encountered in routine pathology practice and a practical approach on how to resolve these issues.

Investigational drugs for treating anal cancer and future perspectives

INTRODUCTION

Anal cancer is a relatively rare malignancy which comprises about 2.5% of all digestive system malignancies in the United States. The majority of cases are squamous cell carcinoma which is closely related to human papilloma virus (HPV) infection. Despite high cure rates with chemoradiation alone, 10 - 20% of patients do develop metastatic disease with little data to guide their treatment.

AREAS COVERED

In this review article, the authors describe the current standard treatment of early and advanced squamous cell carcinoma of the anal canal based on published data. The authors then describe the new approaches to the disease, focusing on new radio sensitizing agents, systemic targeted drugs and immunotherapy.

EXPERT OPINION

The authors believe that current standard treatment options for squamous cell carcinoma of the anal canal are well defined with acceptable results. However the major challenge in the treatment of anal cancer is the lack of randomized or even large single arm Phase II trials due to rarity of the disease, especially in the metastatic disease. But we are slowly making progress. Currently, the most promising areas of research are immunotherapy, targeted therapy and even HPV prevention. We are eagerly anticipating the results of these studies in order to expand the treatment armamentarium.

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.

Natural history of human papillomavirus infections involving anal, penile, and oral sites among HIV-positive men

AIM

The aim of this study was to characterize the natural history of human papillomavirus (HPV) infection at anal canal, penile, and oral sites in HIV-positive men based on their sexual behavior.

METHODS

This is a single-center, prospective cohort study. The prevalence, clearance, and incidence of HPV infection at anal, penile, and oral sites were studied in HIV-positive men who have sex with men (MSM) and heterosexual individuals using multiplex polymerase chain reaction. Risk factors associated with HPV infection were analyzed.

RESULTS

In total, 733 patients (538 MSM, 195 heterosexual) were included in the study between 2005 and 2009. The prevalence, clearance, and incidence of HPV infection were 73%, 30%, and 36% at anal site; 26%, 56%, and 17% at penile site; and 16%, 44%, and 11% at oral site, respectively. At anal site, MSM had a higher HPV prevalence (84% vs. 42%; odds ratio,7.3; 95% confidence interval [CI], 5.2-10.6) mainly for multiple (≥3) HPV types, higher incidence rate (324 vs. 92 new HPV-infected person per 1000 person-years [hazard ratio, 8.1; 95% CI, 3.8-17.3]), and a lower clearance rate (125 vs. 184 cleared HPV-infected person per 1000 person-years [hazard ratio, 0.5; 95% CI, 0.3-0.9]) than did heterosexuals. Similar prevalence, clearance, and incidence rates of penile and oral HPV infection were found between groups. The most common high-risk HPV type for the 3 body sites studied was the HPV-16. Finally, a similar proportion of heterosexuals (7%) and MSM (6%) presented concurrent HPV infections (anal-penile-oral sites). History of anal warts was associated with higher HPV prevalence in the 3 body parts.

CONCLUSIONS

Although MSM presented the highest risk of anal HPV infection, heterosexual men also showed a remarkable prevalence of anal HPV infection and a comparable risk to MSM for penile and oral HPV infection. Taking into account all these results, the careful inspection of the anal canal, penile, and oral sites should at least be routine in each clinic visit of HIV-infected men independently of their sexual behavior.

Long-term effectiveness of infrared coagulation for the treatment of anal intraepithelial neoplasia grades 2 and 3 in HIV-infected men and women

AIMS

To assess the effectiveness and safety of infrared coagulation (IRC) for the ablation of anal intraepithelial neoplasia (AIN) and to provide data on the prevalence of AIN in HIV-infected patients.

PATIENTS AND METHODS

We performed a single-center, retrospective cohort study based on data collected from a prospectively compiled database of outpatients attended in the Clinical-Proctology-HIV-Unit (first visit). The effectiveness (normal anal cytology after 12 months of IRC) and safety of IRC were estimated.

RESULTS

Between January 2005 and December 2011, a total of 69 (5%) patients with biopsy-proven AIN-2 or AIN-3 from among 1518 patients (1310 men; 208 women) were treated with IRC. The prevalence of cytological abnormalities was 49.5% [751/1518; (atypical squamous cells of unknown significance, 14%; low-grade squamous intraepithelial lesions, 27.5%; high-grade squamous intraepithelial lesions, 8%)]. High-resolution anoscopy revealed intra-anal condylomata in 31% of patients (236/751), nonvisualized lesions in 30% (227/751), and visualized lesions (from which biopsy specimens were taken) in 38% (288/751). The histological diagnosis was: AIN-1, 52% (151/288); AIN-2, 15% (44/288); AIN-3, 9% (25/288); normal, 19% (56/288); and nonevaluable, 4% (12/288). IRC was applied in-office in 66 patients (three refused to undergo treatment). At 12 months, all patients (n = 56) had a normal anal cytology result. Seven (13%) patients had biopsy-proven recurrence [mean (range) time-to-recurrence, 30 (18-43) months]. High-risk-human papilloma virus (HPV) infection was detected in all anal lesions (HPV-16 was the most common genotype). Agreement between cytological and histological results was poor.

CONCLUSION

A high prevalence of AIN was found in both HIV-infected men and HIV-infected women. Although randomized clinical trials are lacking, IRC ablation of AIN-2 and AIN-3 lesions without concomitant condylomata could help prevent anal squamous cell carcinoma.

The Lower Anogenital Squamous Terminology Standardization project for HPV-associated lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus (HPV)-associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) project was co-sponsored by the College of American Pathologists (CAP) and the American Society for Colposcopy and Cervical Pathology (ASCCP) and included 5 working groups; three work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted upon at the consensus meeting. The final approved recommendations standardize biologically-relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

The Lower Anogenital Squamous Terminology Standardization Project for HPV-Associated Lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus(HPV)–associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) Project was co-sponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology and included 5 working groups; 3 work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors, and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted on at the consensus meeting. The final, approved recommendations standardize biologically relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail the appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

Immunohistochemical features of the gastrointestinal tract tumors

Gastrointestinal tract tumors include a wide variety of vastly different tumors and on a whole are one of the most common malignancies in western countries. These tumors often present at late stages as distant metastases which are then biopsied and may be difficult to differentiate without the aid of immunohistochemical stains. With the exception of pancreatic and biliary tumors where there are no distinct immunohistochemical patterns, most gastrointestinal tumors can be differentiated by their unique immunohistochemical profile. As the size of biopsies decrease, the role of immunohistochemical stains will become even more important in determining the origin and differentiation of gastrointestinal tract tumors.

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.

Anal warts and anal intradermal neoplasia

For the last five millennia we have been dealing with the annoyance of verrucas. Anogenital human papillomavirus (HPV) infection is the most common sexually transmitted disease in the United States and is increasing in incidence. As in other gastrointestinal conditions, HPV infection can lead to a stepwise transition from normal cells to dysplastic cells and then to invasive anal cancer. Knowledge of the natural history of HPV infection, risk factors, diagnostic tools, and therapeutic methods gives us the tools to adequately prevent, evaluate, treat, and counsel our patients. In this review, the authors detail the diagnosis, management, and treatment of anal condyloma and anal intraepithelial neoplasia with a focus on prevention, early detection, and treatment using current data and technology.

The Lower Anogenital Squamous Terminology Standardization Project for HPV-Associated Lesions: background and consensus recommendations from the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology

The terminology for human papillomavirus (HPV)-associated squamous lesions of the lower anogenital tract has a long history marked by disparate diagnostic terms derived from multiple specialties. It often does not reflect current knowledge of HPV biology and pathogenesis. A consensus process was convened to recommend terminology unified across lower anogenital sites. The goal was to create a histopathologic nomenclature system that reflects current knowledge of HPV biology, optimally uses available biomarkers, and facilitates clear communication across different medical specialties. The Lower Anogenital Squamous Terminology (LAST) Project was cosponsored by the College of American Pathologists and the American Society for Colposcopy and Cervical Pathology and included 5 working groups; 3 work groups performed comprehensive literature reviews and developed draft recommendations. Another work group provided the historical background and the fifth will continue to foster implementation of the LAST recommendations. After an open comment period, the draft recommendations were presented at a consensus conference attended by LAST work group members, advisors, and representatives from 35 stakeholder organizations including professional societies and government agencies. Recommendations were finalized and voted on at the consensus meeting. The final, approved recommendations standardize biologically relevant histopathologic terminology for HPV-associated squamous intraepithelial lesions and superficially invasive squamous carcinomas across all lower anogenital tract sites and detail the appropriate use of specific biomarkers to clarify histologic interpretations and enhance diagnostic accuracy. A plan for disseminating and monitoring recommendation implementation in the practicing community was also developed. The implemented recommendations will facilitate communication between pathologists and their clinical colleagues and improve accuracy of histologic diagnosis with the ultimate goal of providing optimal patient care.

Squamous-cell carcinoma of the anal canal: room for improvement with targeted therapy

Carcinoma of the anal canal is a rare disease accounting for 1-5% of gastrointestinal tract malignancies. However, its incidence is increasing worldwide. Chemoradiation is the standard treatment for most patients with squamous-cell carcinoma of the anal canal and was first described by Nigro et al. Since then, no other effective treatment was developed. Patients with metastatic disease should be considered candidates for clinical trials. New treatment strategies, including molecular target therapies, are warranted in order to improve disease control. Despite the rarity of this disease, it is urgent to improve its treatment by introducing targeted therapy in the arena.

The reporting of anal cytology and histology samples: establishing terminology and criteria

Our understanding of the human papillomavirus (HPV) related cytomorphology and histopathology of the anal canal is underpinned by our knowledge of HPV infection in the cervix. In this review, we utilise cervical reporting of cytological and histological specimens as a foundation for the development of standardised and evidence-based terminology and criteria for reporting of anal specimens. We advocate use of the Australian Modified Bethesda System 2004 for reporting anal cytology. We propose the use of a two-tiered histological reporting system for noninvasive disease – low-grade and high-grade anal intraepithelial neoplasia. These classification systems reflect current understanding of the biology of HPV and enhance diagnostic reproducibility. Biomarkers such as p16INK4A may prove useful in further improving diagnostic accuracy. Standardisation is important because it will increase the value of the data collected as Australian centres develop programs for screening for anal neoplasia.

Dominant role of HPV16 E7 in anal carcinogenesis

Ninety percent of anal cancer is associated with human papilloma viruses (HPVs). Using our previously established HPV transgenic mouse model for anal cancer, we tested the role of the individual oncogenes E6 and E7. K14E6 and K14E7 transgenic mice were treated with dimethylbenz[a]anthracene (DMBA) to the anal canal and compared to matched nontransgenic and doubly transgenic K14E6/E7 mice. K14E7 and K14E6/E7 transgenic mice developed anal tumors (papillomas, atypias and carcinomas combined) at significantly higher rates (88% and 100%, respectively) than either K14E6 or NTG mice (18% and 19%, respectively). Likewise, K14E7 and K14E6/E7 transgenic mice developed frank cancer (carcinomas) at significantly higher rates (85% and 85%, respectively) than either K14E6 or NTG mice (18% and 10%, respectively). These findings indicate that E7 is the more potent oncogene in anal cancer caused by HPVs.

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.

Prevalence of anal intraepithelial neoplasia in women with genital neoplasia

BACKGROUND

Anal intraepithelial neoplasia is believed to be a precursor of anal cancer, and it appears to be related to high-risk human papillomavirus. Women with genital neoplasia have been shown to be at increased risk for anal cancer.

OBJECTIVE

The aim of this study is to determine the prevalence of anal intraepithelial neoplasia in women with genital neoplasia.

DESIGN

This is a cross-sectional study.

SETTING

This study took place at Hospital Nossa Senhora da Conceição, Porto Alegre, Brazil, from May 2008 to April 2010.

PATIENTS

Included in the study were 106 immunocompetent women with a histopathological diagnosis of genital neoplasia and 74 women without gynecologic neoplasia.

MAIN OUTCOME MEASURE

All women underwent high-resolution anoscopy with biopsies of acetowhite areas or abnormal vascular features such as punctation and mosaics for histopathological diagnosis of anal intraepithelial neoplasia.

RESULTS

: The overall prevalence of anal intraepithelial neoplasia was 6.6%. In women with genital neoplasia, the prevalence was 10.4% (95% CI, 5.6%-17.3%), whereas the prevalence was 1.4% (95% CI, 0.07%-6.5%) in women without genital neoplasia (P = .016). The prevalence ratio was 7.68 (95% CI, 1.01-58.21).

LIMITATION

Women with normal results on high-resolution anoscopy were not submitted to random biopsies for ethical reasons. Small lesions could be missed, and thus our findings might be underestimated.

CONCLUSION

The prevalence of anal intraepithelial neoplasia is higher in women with genital neoplasia.

Efficacy and toxicity of chemoradiation in the treatment of HIV-associated anal cancer

PURPOSE

The purpose of this retrospective study is to determine the results and the toxicity of concurrent chemoradiation for squamous cell carcinoma of the anal canal in HIV-positive patients treated at a single institution.

PATIENTS AND METHODS

HIV-positive patients with squamous cell carcinoma of the canal treated at Continuum Cancer Centers-affiliated hospitals were identified from tumor registries. We reviewed hospital and treatment charts to gather data relating to demographics, HIV status including cluster of differentiation 4 (CD4) count and viral load, tumor stage, radiation and chemotherapy treatment, toxicity and local control, and survival.

RESULTS

Thirty-four patients were identified. All patients received radiation and concurrent chemotherapy consisting of either mitomycin-C and 5-fluorouracil (5-FU; 20 patients), cisplatin and 5-FU (13 patients), or 5-FU alone (1 patient). The most frequently reported severe toxicities were dermatologic (50% grade 3 or 4 toxicity) and hematologic (36% grade 3 or 4 toxicity). Actuarial local control and overall survival (OS) at 3 years were 63% and 69%, respectively.

CONCLUSION

Concurrent chemoradiation with cisplatin or mitomycin and 5-FU in HIV-positive patients provides local control and OS comparable to that observed in the HIV-negative population, with acceptable toxicity.

Impact of FDG PET/CT in the staging and the follow-up of anal carcinoma

PURPOSE

The purpose of the study was to assess the diagnostic performance of positron emission tomography/computed tomography and fluorodeoxyglucose (18F) (FDG PET/CT) for the staging and the follow-up of anal carcinoma, and to evaluate the impact of FDG PET/CT on patient management.

MATERIALS AND METHODS

Patients with anal carcinoma were referred to our department from October 2004 until July 2008. The diagnostic performance was evaluated on a perexamination basis and on a per-site basis, together with impact of PET/CT on patient management. The standard of truth was histology when available and, in all cases, follow-up data during at least 6 months.

RESULTS

Fifty-eight FDG PET/CT performed in 44 patients were analysed—22 for initial staging and 36 during follow-up. The detection rate of non-excised tumours on initial examination was 93%. During post-treatment follow-up, FDG PET/CT had, on a per-examination basis, sensitivity for the detection of persistent or recurrent disease of 93% and specificity of 81%, and on a per-site basis, 86% and 97%, respectively. Its negative predictive value was 94% on a per-examination basis and 98% on a per-site basis. FDG PET/CT had an impact on management in nine patients out of 44 (20%), which was relevant in eight of them (89%).

CONCLUSION

FDG PET/CT is an accurate imaging modality in anal cancer. It has an interesting added value during post-treatment follow-up, especially when persistence or recurrence of disease is suspected. Further studies are needed to evaluate whether surveillance by means of FDG PET/CT might have a positive impact on overall survival.

An update on tumors of the anal canal

CONTEXT

The anal canal possesses complex anatomy and histology and gives rise to a variety of tumor types. Challenging issues remain with regard to both the pathologic diagnosis and the clinical management of these tumors.

OBJECTIVES

To provide an updated overview of the histogenesis, clinical and pathologic characteristics, diagnostic terminology, and relevant clinical management of the various types of anal canal tumors.

DATA SOURCES

Recent literature on clinical and pathologic characteristics of anal canal tumors.

CONCLUSIONS

Although most anal canal tumors are of squamous lineage, a complex variety of other tumors also occurs. Recognition of such diverse tumor entities will allow accurate pathologic diagnosis and most optimal clinical management.

A mouse model for human anal cancer

Human anal cancers are associated with high-risk human papillomaviruses (HPV) that cause other anogenital cancers and head and neck cancers. As with other cancers, HPV16 is the most common high-risk HPV in anal cancers. We describe the generation and characterization of a mouse model for human anal cancer. This model makes use of K14E6 and K14E7 transgenic mice in which the HPV16 E6 and E7 genes are directed in their expression to stratified squamous epithelia. HPV16 E6 and E7 possess oncogenic properties including, but not limited to, their capacity to inactivate the cellular tumor suppressors p53 and pRb, respectively. Both E6 and E7 were found to be functionally expressed in the anal epithelia of K14E6/K14E7 transgenic mice. To assess the susceptibility of these mice to anal cancer, mice were treated topically with dimethylbenz[a]anthracene (DMBA), a chemical carcinogen that is known to induce squamous cell carcinomas in other sites. Nearly 50% of DMBA-treated HPV16 E6/E7 transgenic mice showed overt signs of tumors, whereas none of the like-treated nontransgenic mice showed tumors. Histopathologic analyses confirmed that the HPV16 transgenic mice were increased in their susceptibility to anal cancers and precancerous lesions. Biomarker analyses demonstrated that these mouse anal cancers exhibit properties that are similar to those observed in HPV-positive precursors to human anal cancer. This is the first mouse model for investigating the contributions of viral and cellular factors in anal carcinogenesis, and should provide a platform for assessing new therapeutic modalities for treating and/or preventing this type of cancer.

Management of anal squamous intraepithelial lesions

Anal squamous intraepithelial lesions include both low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and are caused by chronic infection with the human papillomavirus (HPV). The disease is increasing in both incidence and prevalence, especially among patients with the following risk factors: homosexual men, acquired or iatrogenic immunosuppression, and presence of other HPV-related diseases. Although the natural history of the disease is unknown, there is significant evidence that untreated HSIL progresses to squamous cell carcinoma in 11% of patients and in up to 50% of patients with extensive disease and immunosuppression. Anal cytology and reflex HPV DNA testing are used to screen for disease, particularly among patients with the aforementioned risk factors. Evaluation of the patient should include physical examination and high-resolution anoscopy (HRA) to evaluate for disease above and below the dentate line. Intervention is warranted and this can be achieved in many ways. The treatment option associated with the best outcomes is ablation directed with HRA, which can be performed in the office or in the operating room with minimal morbidity. This strategy is effective in patients with both low-volume and high-volume disease and is associated with a malignant progression rate of 0.4% in patients with treated HSIL.

Management of anal squamous intraepithelial lesions

Anal squamous intraepithelial lesions include both low-grade squamous intraepithelial lesions (LSIL) and high-grade squamous intraepithelial lesions (HSIL) and are caused by chronic infection with the human papillomavirus (HPV). The disease is increasing in both incidence and prevalence, especially among patients with the following risk factors: homosexual men, acquired or iatrogenic immunosuppression, and presence of other HPV-related diseases. Although the natural history of the disease is unknown, there is significant evidence that untreated HSIL progresses to squamous cell carcinoma in 11% of patients and in up to 50% of patients with extensive disease and immunosuppression. Anal cytology and reflex HPV DNA testing are used to screen for disease, particularly among patients with the aforementioned risk factors. Evaluation of the patient should include physical examination and high-resolution anoscopy (HRA) to evaluate for disease above and below the dentate line. Intervention is warranted and this can be achieved in many ways. The treatment option associated with the best outcomes is ablation directed with HRA, which can be performed in the office or in the operating room with minimal morbidity. This strategy is effective in patients with both low-volume and high-volume disease and is associated with a malignant progression rate of 0.4% in patients with treated HSIL.

Anal neoplasms

A variety of lesions comprise tumors of the anal canal, with carcinoma in situ and epidermoid cancers being the most common. Less common anal neoplasms include adenocarcinoma, melanoma, gastrointestinal stromal cell tumors, neuroendocrine tumors, and Buschke-Lowenstein tumors. Treatment strategies are based on anatomic location and histopathology. In this article different tumors and management of each, including a brief review of local excision for rectal cancer, are discussed in turn.

Prevalence of anal squamous intra-epithelial lesion in women presenting genital squamous intra-epithelial lesion

OBJECTIVE

To determine the frequency of anal squamous intra-epithelial lesions (ASIL) in women with genital squamous intra-epithelial lesions (GSIL).

STUDY DESIGN

In a cross sectional study, 184 patients with histopathological diagnosis of GSIL and 76 controls without GSIL, were submitted to anuscopy in order to determine the presence of ASIL. All the women were HIV-negative with anal aceto-white lesions were biopsed for histological diagnosis.

RESULTS

The frequency of ASIL was 17.4% in the GSIL group (3.2% high grade ASIL) and only 2.6% in the control group (0% high grade ASIL) (p<0.001). All the high grade ASIL diagnoses were found in women with cervical SIL.

CONCLUSION

Women presenting GSIL have high prevalence of ASIL.

Diagnostic problems in anal pathology

Anal squamous cell carcinoma and its precursor lesions are increasing in incidence in the United States and Europe. This trend predates human immunodeficiency virus/acquired immune deficiency syndrome and has been associated with persistent high-risk human papilloma virus (HPV) genotype infection, previous lower genital tract dysplasia/carcinoma, high frequency anoreceptive intercourse, heavy cigarette smoking, immunosuppression in solid organ transplant and immune disorders, and human immunodeficiency virus seropositivity. Screening protocols for at-risk patients are under active investigation and pathologists are often asked to assess anal canal and perianal biopsies for the presence of dysplasia and/or invasive carcinoma. Because underdiagnosis and overdiagnosis of anal cancer and precancer may lead to inappropriate treatment, it is important for the pathologist to be aware of current screening strategies, specific risk lesions, and the role of pathology in initial diagnosis and evaluation of anal biopsy and/or resection specimens. Standardized histologic criteria and uniform terminology should be used for reporting all anal canal and perianal squamous intraepithelial lesions. HPV subtyping, anal cytology, and recently identified biomarkers, such as p16 and Becton Dickinson ProEx C may provide additional information in problematic cases, but it is important to be aware of the limitations of these assays. HPV has been linked to all the major histologic subtypes of anal carcinoma (eg, basaloid, cloacogenic, transitional, etc.) and this association is strongest for anal canal lesions. With the possible exception of the microcystic pattern, histologic subtype does not seem to predict prognosis; and anal squamous cell carcinomas should be classified as either keratinizing or nonkeratinizing. Poorly differentiated squamous cell carcinomas have a worse prognosis and should be distinguished from poorly differentiated adenocarcinoma, melanoma, and neuroendocrine tumors. Very well differentiated squamous cell carcinoma with pushing margins (so-called giant condyloma of Buschke and Lowenstein) should be classified as verrucous carcinoma; this tumor shows aggressive local infiltration but does not metastasize. As all anal condylomata may harbor foci of high-grade dysplasia or invasive carcinoma, careful sectioning and complete histologic examination is required.