Anal cancer: an HIV-associated cancer

A comparative study of the genotype profiles of high-risk human papillomavirus infection in male and female HIV-positive patients and their correlation with anal cytology and biopsy

INTRODUCTION

Although anal cancer is more common in women, most of the studies on the role of high-risk human papillomavirus (hrHPV) infection in anal squamous lesions have focused on high-risk male patients. Therefore, we compared the genotype profile and clinicopathologic correlation of hrHPV infection in human immunodeficiency virus-positive (HIV+) men and women.

MATERIALS AND METHODS

We retrospectively analyzed 2254 HIV+ patients (1931 men and 323 women) who had undergone anal Papanicolaou tests at our institution; 1189 of them also had follow-up biopsy data available. HPV genotyping was performed using the Roche Cobas system and correlated with the cytologic and histologic diagnosis.

RESULTS

Compared with the HIV+ men, the HIV+ women had a significantly lower rate of hrHPV infection (67.5% versus 78.5%; P < 0.0001) but a significantly higher rate of high-grade squamous intraepithelial lesions (HSILs) on anal Papanicolaou tests (4.6% versus 2.5%; P < 0.05). Other high-risk HPV (ohrHPV), as a group, is much more common than HPV16 or HPV18 in both genders. HIV+ women had significantly lower HPV16 and ohrHPV infection rates than did HIV+ men. However, the HPV18 infection rates were similar between HIV+ women and HIV+ men. For both genders, the rates of HSILs or high-grade anal intraepithelial neoplasia (AIN2-3) were significantly increased when coinfection of ohrHPV with either HPV16 or HPV18 was present.

CONCLUSIONS

Although both HIV+ men and HIV+ women have an increased risk of hrHPV infection, HIV+ women have different hrHPV genotype profiles and higher rates of high-grade lesions. Coinfection with different genotypes of hrHPV can significantly increase the risk of HSILs or AIN2-3 in both genders and could requires vigilant clinical and laboratory follow-up.

A 12-year retrospective evaluation of anal pre-cancerous lesions and cancer in people living with HIV-1 infection in the Southeastern U.S

Background

Anal cancer is rare in the general population in both genders in the US, but an increased incidence of anal cáncer (AC) has been reported among people living with HIV-1 infection (PLWH) and little is known among the population in South US.

Methods

In a retrospective study design, electronic health records from 2006 to 2018 were reviewed in a HIV clinical cohort at the University of Alabama at Birmingham. Associations of demographic, sociodemographic, and HIV-clinical indicators were examined in univariate analyses between high-grade squamous intraepithelial lesions (HSIL) and AC cases and condition-free individuals. Factors for anal/rectal cytology screening tests among PLWH were also assessed over time. Ages at onset of anal cancer were compared with the general US population reported by the National Surveillance, Epidemiology, and End Results Program.

Results

A total of 79 anal HSIL (96% men) and 43 cancer (100% men) patients were observed along with 4367 HSIL/cancer-free patients (75.9% men). HSIL (P < 0.0001) and AC (0.0001 < P < 0.01) were associated with being men who have sex with men (MSM). An incidence of 258 per 100,000 person-year was observed among this clinical cohort of PLWH. PLWH who were 45–54 years appeared to be at highest risk of AC (58.1%), as compared to those 55–64 years in the general population. Overall, 79% of PLWH anal cancers were diagnosed among those under 55 years (vs 39.5% in general population) indicating early onset of AC. In total 29.1% of HSIL and 44.2% of AC patients had not received an anal/rectal cytology examination 1 year prior to diagnosis.

Conclusion

AC incidence among HIV-infected men was 161 times higher than general population with an earlier age of onset/diagnosis. Many patients with AC had missed screening opportunities that could potentially have captured neoplasia in pre-cancerous stages. AC-related screening guidelines need to be integrated into routine clinical care, especially among PLWH at highest risk such as MSM and those with lower CD4 counts.

Difference in toxicity between HIV-positive and HIV-negative patients with squamous-cell cancer of the anal canal treated with concomitant radio-chemotherapy

Background

The incidence of squamous cell carcinoma of the anal canal has been increasing over the last 30 years. HIV has been found to be a risk factor for the development of this disease; radio-chemotherapy (RTCT) may also be more toxic than in HIV-negative patients. The study aims at assessing whether there are any differences in terms of toxicity between HIV-positive and HIV-negative patients treated with concomitant RTCT.

Methods

Search in MEDLINE, EMBASE, CENTRAL (via Cochrane Library-Wiley), DARE, LILACS bibliographic databases. Experimental and analytical observational studies with at least two comparative arms were included: squamous-cell (SC) anal-canal cancer (ACC) treated with RTCT in HIV-positive vs. HIV-negative patients.

Results

Fifteen publications, 14 retrospective studies and 1 systematic review, were found. All radiotherapy (RT) techniques and all chemotherapeutic agents used to manage this disease were included. No differences were found in terms of duration (P=0.67) and dose (P=0.53) of RT, while CT results were contradictory. Acute and hematological toxicities were significantly higher in HIV-positive patients, while gastrointestinal, dermatological and chronic toxicities did not significantly differ between the two groups. Given the high heterogeneity of the studies, no objective comparison could be made between studies that included antiretrovirals and those that did not.

Conclusions

HIV-positive patients may be at higher risk for acute and hematological toxicity than HIV-negative patients. A precise conclusion cannot be drawn on the use of antiretrovirals, given the high heterogeneity of data.

HPV genotypes detected by linear array and next-generation sequencing in anal samples from HIV positive men who have sex with men in Mexico

The incidence of anal cancer has been rising, especially in HIV+ patients and has been associated with HPV infection. HIV+ patients are more at risk of HPV coinfection and are seven times more likely to have persistent HPV infection; moreover, HIV+ men have an increased risk of developing anal cancer compared to HIV+ women. The development of screening strategies for the detection of HPV in HIV+ men is of major importance; however, there is not enough information about the HPV genotypes and variants that are colonizing the anal epithelia of HIV+ men in diverse geographical regions. Therefore, this work was aimed at identifying HPV genotypes present in the anal epithelium of HIV+ men who have sex with men (MSM), with or without anal lesions (n = 75). For HPV genotyping, two approaches were performed: Linear Array HPV Genotyping Test and next-generation sequencing (NGS). In general, the six most frequent HPV genotypes found by Linear Array were HPV6, 62, 61, 81, 16 and 51. On the other hand, employing NGS, a total of 36 HPV genotypes belonging to both alpha and beta genera were found. The genotypes with the greatest number of reads, according to the diagnostic group, were: HPV81, 45, 6, 51 and 61 in MSM without anal lesions (WAIN); HPV6, 61, 70, 62 and 66 in MSM with atypical lesions (AAL); HPV6, 11, 66, 81 and 61 in MSM with anal intraepithelial neoplasia grade I (AIN I); and HPV16, 81, 58, 61 and 52 with AIN III. Additionally, a great diversity of L1 variants was observed, especially in genotypes HPV16, 58, 61, 52, 45 and 59.

Anal cancer: current standards in care and recent changes in practice

Answer questions and earn CME/CNE The management of squamous cell carcinomas of the anal canal has evolved from surgery as first-line treatment to curative chemoradiation, with surgery reserved for salvage. Significant progress has been made in understanding how to most effectively deliver chemotherapy and reduce toxicity through advancements in radiation delivery. The purpose of this article is to review the multimodality approach to the diagnosis and management of anal cancer based on a review of the published data and in light of available guidelines.

The value of high-resolution anoscopy in the diagnosis of anal cancer precursor lesions in hiv-positive patients

CONTEXT: Anal cancer, although a still rare disease, is being observed in ascending rates among some population segments known to be at risk for the development of the disease. Human papillomavirus (HPV) infection, immunodepression and anal intercourse are some factors associated with the development of the malignancy. Its similarities to cervical cancer have led to many studies aiming to establish guidelines for detecting and treating precursor lesions of anal cancer, with the goal of prevention. High-resolution anoscopy is routinely used for the diagnosis of anal cancer precursor lesions in many centers but the medical literature is still deficient concerning the role of this diagnostic modality. OBJECTIVES: To evaluate diagnostic validation and precision measures of high-resolution anoscopy in comparison to histopathological results of anal biopsies performed in HIV-positive patients treated at the Tropical Medicine Foundation of Amazonas, AM, Brazil. To observe any possible association between some risk factors for the development of anal cancer and the presence of anal squamous intraepithelial lesions. METHODS: A hundred and twenty-eight HIV-positive patients were submitted to anal canal cytological sampling for the detection of HPV infection by a PCR based method. High-resolution anoscopy was then performed after topical application of acetic acid 3% in the anal canal for 2 minutes. Eventual acetowhite lesions that were detected were recorded in respect to location, and classified by their tinctorial pattern, distribution aspect, relief, surface and vascular pattern. Biopsies of acetowhite lesions were performed under local anesthesia and the specimens sent to histopathological analysis. The patients were interviewed for the presence of anal cancer risk factors. RESULTS: The prevalences of anal HPV infection and of anal squamous intraepithelial lesions in the studied population were, respectively, 79% and 39.1%. High-resolution anoscopy showed sensibility of 90%, specificity of 19.23%, positive predictive value of 41.67%, negative predictive value of 75%, and a kappa coefficient of 0.076. From the analyzed lesions, high-grade squamous intraepithelial lesions was more frequently observed in association to dense (68%), flat (61%), smooth (61%), non-papillary (83%) and normal vascular pattern (70%) acetowhite lesions, while low-grade squamous intraepithelial lesions tended to be associated to dense (66%), flat-raised or raised (68%), granular (59%), non-papillary (62%) and normal vascular pattern (53%) acetowhite lesions. No statistical significance was observed as to the association of epidemiological characteristics and of most of the investigated anal cancer risk factors and presence of acetowhite lesions or anal squamous intraepithelial lesions. However, anal receptive sex and anal HPV infection were significantly associated to anal squamous intraepithelial lesions (P = 0.0493 and P = 0.006, respectively). CONCLUSION: High-resolution anoscopy demonstrated to be a sensitive, but not specific test for the detection of anal squamous intraepithelial lesions. Risk factors anal receptive sex and anal HPV infection were significantly associated to the presence of anal squamous intraepithelial lesions. Based on high-resolution anoscopy image data, acetowhite lesions relief and surface pattern were prone to distinguish between low-grade squamous intraepithelial lesions and high-grade squamous intraepithelial lesions.

The role of human papillomavirus infection in breast cancer

Breast cancer is the leading female cancer and the third most common cause of cancer deaths worldwide. Many studies have suggested a possible link between breast cancer pathogenesis and viral infection, particularly mouse mammary tumour virus, simian virus 40, Epstein-Barr virus, and human papillomavirus (HPV). A significant number of recent studies have reported that approximately 29% of human breast cancer tissues were positive for high-risk HPV subtypes, especially HPV subtypes 16, 18, or 33. In contrast, several other investigations did not detect any HPV subtypes in either breast cancer tissue or normal breast tissue from patients diagnosed with breast cancer. Given these conflicting data and the established complexity of the association between HPV with other cancers, a definitive relationship between human breast cancer and HPV infection has not been determined. Recent advances in laboratory methodologies aim to overcome the inherent challenges in detecting HPV in breast cancer tissue. There is an urgent need to obtain additional evidence in order to assess the possibility of breast cancer prevention using HPV vaccines.

HIV- positive anal cancer: an update for the clinician

Anal cancer used to be a rare cancer traditionally associated with elderly women. There are approximately 5260 cases per year in the U.S. (1). The onslaught of the Human Immunodeficiency Virus (HIV) virus has led to a change in anal cancer demographics. Anal cancer is on the rise in the U.S and the number of anal cases documented has quadrupled in the past 20 yrs correlating with the rise of the HIV epidemic. The incidence of anal cancer is 40 to 80 fold higher in the HIV positive (HIV+) population when compared to the general population (2). With the advent of highly active antiretroviral therapy (HAART), HIV+ patients are living longer as less are progressing to AIDS. As a consequence non AIDS defining cancers such as anal cancer are on the rise. Factors implicated in the etiology of anal cancer in HIV+ patients include (Human papillomavirus) HPV virus status, sexual habits, and a history of smoking. HPV 16 and receptive anal intercourse (RAI) increase the risk of anal cancer by 33% over the general population. In the general population, the rate of anal cancer is approximately 0.9 cases per 100,000. In patients with a history of RAI, the rate approaches 35 cases per 100,000 which is equivalent to the prevalence of cervical cancer (3). Smokers are eight times more likely to develop anal cancer. There has been much discussion about tailoring treatment decisions in HIV+ patients with anal cancer. This review focuses on squamous cell carcinomas of the anal canal which comprise 80 to 90% of all anal cancers diagnosed and highlight key issues in the management of HIV+ anal cancer patients including recent clinical trials.

Behavioral risk disparities in a random sample of self-identifying gay and non-gay male university students

This Internet-based study was designed to compare health risk behaviors of gay and non-gay university students from stratified random cross-sectional samples of undergraduate students. Mean age of the 4,167 male participants was 20.5 (+/-2.7) years. Of these, 206 (4.9%) self-identified as gay and 3,961 (95.1%) self-identified as heterosexual. After adjusting for selected characteristics and clustering within university, gay men had higher odds of reporting: multiple sexual partners; cigarette smoking; methamphetamine use; gamma-hydroxybutyrate (GHB) use; other illicit drug use within the past 30 days and during lifetime; and intimate partner violence (IPV). Understanding the health risk behaviors of gay and heterosexual men is crucial to identifying associated factors and intervening upon them using appropriate and tailored strategies to reduce behavioral risk disparities and improve health outcomes.

High-resolution anoscopy in the diagnosis of anal cancer precursor lesions in renal graft recipients

BACKGROUND

Renal graft recipients are one of the population groups known to be at high risk of developing anal cancer. This study investigated the presence of subclinical anal squamous intraepithelial lesions and the diagnostic ability of high-resolution anoscopy in detecting these lesions in renal graft recipients followed-up in Manaus.

METHODS

In a cross-sectional study, 50 renal graft recipients were interviewed and submitted to high-resolution anoscopy with biopsies of acetowhite lesions or of the anal transition zone mucosa when acetowhitening was absent. Considering the histopathological reports of the examined anal specimens as the gold standard, the diagnostic validation and precision measures of high-resolution anoscopy were calculated as well as the prevalence of anal squamous intraepithelial lesions in the studied population.

RESULTS

In 42 renal graft recipients with satisfactory histopathological readings, prevalence of anal squamous intraepithelial lesions or condyloma acuminatum (ASIL-ACU) was 23.81%. Sensitivity of high-resolution anoscopy was 100%; specificity, 65.63%; positive predictive value, 47.62%; negative predictive value, 100%; and kappa coefficient, 0.48.

CONCLUSIONS

With a prevalence of 23.81% of subclinical ASIL-ACU lesions, the studied renal graft recipients had all these lesions detected by high-resolution anoscopy, notwithstanding most anal transition zone acetowhitened biopsied areas did not reveal histopathological aspects of anal cancer precursor lesions or condyloma acuminatum. Therefore, greater experience with the diagnostic tool was felt necessary to enhance its positive predictive value, specificity and diagnostic precision.

Anal intraepithelial neoplasia and anal cancer in dermatological practice

Anal intraepithelial neoplasia is considered to be a precursor lesion of invasive anal cancer. It is now increasingly recognized in high-risk groups, such as men who have sex with men and HIV-infected patients. Human papillomaviruses are considered to be an important aetiological agent in both anal intraepithelial neoplasia and anal cancer. Dermatologists are likely to encounter these conditions among the differential diagnoses to be considered in high-risk patients presenting with perianal and anal lesions. Anal cancer rates are also increasing among the HIV-infected and HIV-non-infected population. The successful treatment of anal intraepithelial neoplasia may reduce the risk of subsequent development of anal cancer. However, current therapies for anal intraepithelial neoplasia may be associated with treatment-related morbidity and are not well validated. It is currently not proven that they reduce the likelihood of the development of anal cancer. Nevertheless, screening for anal intraepithelial neoplasia is being advocated for high-risk groups and may become standard dermatological care for these patients. In view of recent developments in the understanding of this condition, this article reviews the current understanding of anal intraepithelial neoplasia and its treatment from a dermatological perspective.

ACR Appropriateness Criteria® on Treatment of Anal Cancer

Anal cancer is a relatively rare neoplasm, accounting for roughly 4,500 cases per year. The evolution of the definitive treatment of anal cancer from a surgical to a nonsurgical approach, however, has been viewed as a model disease site in a larger paradigm shift in medicine. Organ preservation, in this case a functional anal sphincter, and durable cure are obtainable goals. To this end, anal cancer is a disease best treated primarily with chemoradiation. Although appropriate treatment can produce acceptable results, further investigation and improvement in therapy are still needed.

Human papillomavirus E7 oncoprotein dysregulates steroid receptor coactivator 1 localization and function

High-risk human papillomaviruses (HPVs) are present in virtually all cervical carcinomas. However, the majority of women infected with high-risk HPVs do not develop cervical cancer. Therefore, cofactors must contribute to the development and progression of cervical cancer. Although numerous studies have implicated steroid hormones as cofactors in the initiation and progression of cervical neoplasia, the molecular mechanisms by which they contribute to cervical carcinogenesis are currently unknown. These observations led us to investigate a newly discovered association of the high-risk HPV type 16 (HPV16) E7 oncoprotein with steroid receptor coactivator 1 (SRC-1), an essential component of steroid hormone signaling. HPV16 E7 has been previously reported to interact with p300 and p300/CBP-associated factor (PCAF), members of some SRC-1 transcriptional complexes. We demonstrate here that HPV16 E7 associates in vivo and in vitro with SRC-1 independently of p300 and PCAF. Luciferase reporter constructs under the control of either the interleukin-8 promoter or a promoter containing multimerized synthetic estrogen response elements were used to determine the effect of high- and low-risk HPV E7 expression on SRC-1-mediated transcription. In addition, histone acetyltransferase (HAT) assays were performed to determine the effect of HPV E7 on SRC-1-associated HAT activity. These experiments reveal that HPV16 E7 expression down-regulates SRC-1-mediated transcription and SRC-1-associated HAT activity. SRC-1 localization experiments show that SRC-1 is relocalized to the cytoplasm in the presence of high- and low-risk HPV E7 proteins. Our data suggest that HPV E7 proteins dysregulate hormone-dependent gene expression by association with and relocalization of SRC-1. Dysregulation of SRC-1 localization and function by HPV E7 may provide insight into the molecular mechanisms by which steroid hormones act as cofactors in the induction and progression of cervical neoplasia.

Molecular cytogenetic characterization of human papillomavirus16-transformed foreskin keratinocyte cell line 16-MT

Anogenital cancers are closely associated with human papillomavirus (HPV), and HPV-infected individuals, particularly those with high-grade dysplasias, are at increased risk for cervical and anal cancers. Although genomic instability has been documented in HPV-infected keratinocytes, the full spectrum of genetic changes in HPV-associated lesions has not been fully defined. To address this, we examined an HPV16-transformed foreskin keratinocyte cell line, 16-MT, by GTG-banding, spectral karyotyping (SKY), and array comparative genomic hybridization (array CGH); these analyses revealed multiple numerical, complex, and cryptic chromosome rearrangements. Based on GTG-banding, the 16-MT karyotype was interpreted as 78-83,XXY,+add(1)(p36.3),+3,+4,+5,+5,+7,+8,+i(8)(q10)x2,+10,?der(12),der(13;14)(q10;q10),+15,+16,add(19)(q13.3),+21,+21,-22[cp20]. Multicolor analysis by SKY confirmed and further characterized the anomalies identified by GTG banding. The add(1) was identified as a der(1)(1qter-->1q25::1p36.1-->1qter), the add(19) as a dup(19), and the der(12) interpreted as a der(11) involving a duplication of chromosome 11 material and rearrangement with chromosome 19. In addition, previously unidentified der(9)t(9;22), der(3)t(3;19), and der(4)t(4;9) were noted. The 16-MT cell line showed losses and gains of DNA due to unbalanced translocations and complex rearrangements of regions containing known tumor suppressor genes. Chromosomal changes in these regions might explain the increased risk of cancer associated with HPV. Also, array CGH detected copy-number gains or amplifications of chromosomes 2, 8, 10, and 11 and deletions of chromosomes 3, 4, 11, and 15. These results provide the basis for the identification of candidate oncogenes responsible for cervical and anal cancer in amplified regions, and for putative tumor suppressor genes in commonly deleted regions like 11q22-23. Furthermore, these data represent the first full characterization of the HPV-positive cell line 16-MT.

Primary care health issues among men who have sex with men

PURPOSE

The purpose of the article is to examine "appropriate" health care for men who have sex with men (MSM), which is not to suggest "special" health care. As a group, MSM are at increased risk for sexually transmitted infections, anal cancer, and mental health disorders. Focus areas in this article will address health issues that the primary care nurse practitioner (NP) may encounter in clinical practice: anal carcinoma, sexually transmitted diseases (STDs), high-risk sexual practices, depression, and substance abuse were topics chosen for inclusion in this article. These topics were among those highlighted in the Healthy People 2010 Companion Document for LGBT Health, which served to examine the healthcare disparities and lack of access to needed services related to sexual orientation.

DATA SOURCE

Extensive literature review of research articles, journals, clinical practice guidelines, books, and public health department Internet Web sites.

CONCLUSIONS

There are unique health disparities that exist for MSM related to social, emotional, and mental health factors, in addition to physical issues such as STDs. There is an increasing need for primary care providers to be aware of these disparities, as well as the factors that influence these disparities, in order to provide multidimensional care and health counseling that is unique to NP practice.

IMPLICATIONS FOR PRACTICE

Both the primary care NP and the patient should be aware of the unique healthcare issues among MSM that should be incorporated into the patient's routine health maintenance program. As primary care providers, it is within the standards of practice for NPs to provide culturally competent care, along with health promotion and disease prevention for MSM.

Avaliação dos resultados do tratamento de 14 doentes de carcinoma espinocelular anal

A radioquimioterapia (RT/QT) tornou-se o tratamento de escolha para o carcinoma espinocelular anal (CEC). Na recidiva local ou na persistência da doença, deve-se instituir o tratamento cirúrgico. OBJETIVO: O objetivo deste estudo retrospectivo foi analisar os resultados do tratamento de doentes de CEC anal. MÉTODO: Acompanhamos 17 pacientes com diagnóstico anátomo-patológico de carcinoma espinocelular anal. Eram 14 (82,3%) do sexo feminino e três (17,8%) do masculino. A idade variou de 36 a 78 anos, com média de idade de 59,1 anos. Utilizando a classificação TNM, tivemos quatro (23,6%) no estádio I, seis (35,2%) no II, quatro (23,6%) no IIIa e três (17,6%) no IIIb. Todos foram submetidos a tratamento inicial com RT/QT, exceto um submetido a ressecção local. Definimos que a biópsia negativa, realizada entre 12 e 16 semanas após esse tratamento, determinaria o controle local da doença. RESULTADOS: Perdemos seguimento de três doentes (17,6%). Seguimos os 14 restantes (82,3%) entre um e cinco anos. Todos os doentes nos estádios I e II (10) apresentaram regressão total da doença, enquanto que três (75%) nos estádios IIIa e IIIb tiveram remissão completa. Realizamos a amputação abdomino-perineal de resgate em dois doentes e ressecção local em outros dois. A recidiva local ocorreu em dois (20%) nos estádios I e II e em dois (75%) nos estádios mais avançados (IIIa e IIIb). A sobrevivência em 3 anos foi de 100% nos que se encontravam nos estádios I e II, embora o controle da doença fosse atingido em oito (80%). Nos quatro doentes que estavam nos estádios IIIa e IIIb, a sobrevivência em um ano foi de 75% e em três anos foi de 25%. Esse último permanece livre da doença. Complicações do tratamento radioterápico ocorreram em oito doentes (57,1%). Nenhum óbito foi constatado durante o tratamento RT/QT. Os dois doentes, (14,3%) com sorologia positiva para HIV, apresentavam infecção anal pelo Papilomavírus humano (HPV). CONCLUSÃO: A análise dos nossos resultados evidenciou que o esquema de tratamento empregado foi efetivo para o controle local e preservação da função esfincteriana do ânus e que, na falha do tratamento radioquimioterápico, a operação de resgate controlou localmente a doença.

Human papillomavirus and anal intraepithelial neoplasia

PURPOSE OF REVIEW

A review of recent developments in the understanding of the natural history of anal squamous carcinoma arising from areas of high-grade anal intraepithelial neoplasia.

RECENT FINDINGS

Anal intraepithelial neoplasia is a consequence of chronic human papillomavirus infection in the anal canal and appears to be driven by high viral loads of human papillomavirus. In men who have sex with men with multiple sexual partners prevalent human papillomavirus infection does not decline with age, in contrast to heterosexual patients. Anal intraepithelial neoplasia is equally prevalent in different age groups of men who have sex with men, but in other respects what is known of its natural history resembles that of cervical intraepithelial neoplasia. Low-grade lesions frequently resolve, but high-grade lesions are much more stable. HIV-positives who practise receptive anal intercourse are at highest risk of anal intraepithelial neoplasia. Screening is easy to perform using cytology; the limitations of anal cytology being similar to those of cervical cytology. Patients with any grade of cytological abnormality require further investigation, ideally with high-resolution anoscopy, every 6 months. Successful treatments for individual small to medium-sized high-grade lesions include trichloroacetic acid, infra-red coagulation and laser. In HIV-positive patients the development of new lesions elsewhere is very likely. Topical agents for multifocal disease include imiquimod and cidofovir.

SUMMARY

There is a need for large prospective cohort studies in men who have sex with men and HIV-positive patients to further our understanding of this disease and to evaluate treatment strategies.

Viral carcinogenesis and genomic instability

Oncogenes encoded by human tumor viruses play integral roles in the viral conquest of the host cell by subverting crucial and relatively non-redundant regulatory circuits that regulate cellular proliferation, differentiation, apoptosis and life span. Human tumor virus oncoproteins can also disrupt pathways that are necessary for the maintenance of the integrity of host cellular genome. Some viral oncoproteins act as powerful mutator genes and their expression dramatically increases the incidence of host cell mutations with every round of cell division. Others subvert cellular safeguard mechanisms intended to eliminate cells that have acquired abnormalities that interfere with normal cell division. Viruses that encode such activities can contribute to initiation as well as progression of human cancers.

Genital human papillomavirus infection in men

Genital human papillomavirus (HPV) infection, globally one of the most common sexually transmitted infections, is associated with cancers, genital warts, and other epithelial lesions. Although a consistent and coherent picture of the epidemiology and pathogenesis of genital HPV infections in women has developed over the past two decades, less is known about these infections in men. Available data suggest that, as with women, most genital HPV infections in men are symptomless and unapparent, and that HPV16 is probably the most frequently detected type. In populations of similar age, the prevalence of specific HPV types is usually lower in men than in women. Whether this observation relates to lower incidence or shorter duration of infection in men than in women has not yet been determined. Seroprevalence of specific anti-HPV antibodies also seems to be lower in men than in women of similar age, a difference that might be due to lower viral load, lower incidence or duration of infection or lower antibody responses, or both, in men compared with women. Differences in sexual behaviour may also be important predictors of genital HPV infection. With the anticipated availability of prophylactic HPV vaccines in the near future, it becomes increasingly important to understand the incidence and duration of HPV infections in men to develop cost-effective approaches to prevention through a combination of immunisation and promotion of risk-reduction strategies.

Anal dysplasia in HIV-infected women with cervical and vulvar dysplasia

OBJECTIVE

To describe the findings of high-resolution anoscopy (HRA) in human immunodeficiency virus (HIV)-infected women with a history of lower genital tract dysplasia.

MATERIALS AND METHODS

A retrospective chart review of all HIV-infected women undergoing HRA from 2002 to 2003 was conducted. Demographic and clinical information, including the most recent cervical and vaginal cytologic results and colposcopic evaluations, were collected from medical records. These data were compared with anal cytologic and histologic findings from HRA.

RESULTS

Eight patients were identified, with a mean age of 42 years. The mean duration of known HIV infection was 12 years. All eight patients had a previous history of treatment for cervical dysplasia or carcinoma. Five patients also had a history of high-grade vulvar dysplasia. The most recent cervical and vaginal cytologic results for all patients were abnormal. Seven patients underwent HRA because of suspected anal intraepithelial neoplasia (AIN); of these, four patients had perianal warts and three had diffuse high-grade vulvar dysplasia. One patient was referred for HRA because of high-grade dysplasia on vaginal cytologic analysis with a negative colposcopic and urologic evaluation. All eight patients (100%) had abnormal anal cytologic results with histologically proven AIN. Five patients had AIN 2,3, and three patients had AIN 1 and anal condyloma. Two of the three patients with AIN 1 had high-grade perianal dysplasia.

CONCLUSIONS

High-resolution anoscopy identified anal dysplasia in 100% of eight HIV-infected women with human papilloma virus-related dysplasia of the lower genital tract. High-resolution anoscopy should be considered as part of the evaluation for the extent of disease in HIV-infected women with cervical and vaginal dysplasia, condyloma, and dysplasia of the perineum.

Anal intraepithelial neoplasia

Background

Anal intraepithelial neoplasia (AIN) is believed to be a precursor of anal squamous cell cancer and its incidence is rising in high-risk groups, particularly those infected with the human immunodeficiency virus (HIV). The natural history of AIN is unclear and management strategies are lacking.

Methods

This review is based on a literature search (Medline and PubMed) with manual cross-referencing of all articles related to AIN.

Results and conclusions

The aetiology of AIN is intricately linked with human papilloma viruses. The pathological processes involved in the progression of AIN are becoming clearer but the natural history, particularly the rate of progression to invasive cancer, remains unknown. There is no standard management for AIN and this is mainly due to difficulties in both diagnosis and treatment. A variety of treatment options have been tried with varying success. Surgery is associated with significant recurrence, particularly in HIV-positive patients. Non surgical approaches with imiquimod, photodynamic therapy and vaccination are appealing, and further work is required. Long-term follow-up of these patients is essential until the natural history of AIN becomes clearer.

Anogenital neoplasia in AIDS

PURPOSE OF REVIEW

We review the recent literature on anogenital neoplasms in AIDS, with emphasis on cancers associated with HPV infection. Immune reactivity to HPV as well as novel immunotherapeutic and preventative strategies are discussed.

RECENT FINDINGS

Many AIDS-associated neoplasms are associated with HPV infection. Whether cervical cancer is truly an AIDS-associated neoplasm has recently been questioned, while the association of anal cancer with AIDS in both males and females is more convincing. Recent reports cast doubt on the efficacy of HAART therapy for HPV-induced anogenital neoplasms, despite efficacy in improving disease caused by other infectious agents. We include here new data on humoral and cellular immune responses to HPV. VLP serology has been reported to be associated with outcome of cervical cancer. VLP seropositivity has been reported to be a favorable prognostic sign in women with HPV 16 positive cervical carcinoma. Several investigators have questioned the immunogenicity of the oncogenic HPV type 16 compared with other HPV types. It has recently been found that in HIV-infected patients, lymphoproliferative cellular immune responses (CMI) to HPV 16 peptides are not associated with CD4 counts, whereas responses to recall antigens and mitogens are associated with CD4 counts. CD4 + T cells may not be responsible for protective cellular immune responses to HPV. VLP serology and CMI responses may be the future intermediate surrogate biomarkers for HPV-associated anogenital neoplasia trials. Several new therapeutic vaccine strategies for management of HPV-induced neoplasia are reviewed.

SUMMARY

Most anogenital neoplasms occurring with increased frequency in patients with HIV/AIDS are associated with HPV infections. Current treatment strategies are not effective in clearing anogenital HPV infection and need improvement. Immunotherapy with novel vaccines will provide both prevention and therapy for these common malignancies.

Anal cancer and its precursors in HIV-positive patients: perspectives and management

Anal cancer is an increasing problem among HIV-infected persons. Although patients are living longer and with better quality of life because of treatment with HAART, they remain at risk for invasive anal cancer and its precursor, anal HSIL. Given the substantial numbers of patients with anal HSIL, further studies need to be done to determine the efficacy and optimal mode of treatment of HSIL, to define the optimal method for screening patients at risk, to define the best way to follow up patients with documented HSIL to ensure early detection, to define prognostic factors for progression to invasive cancer, and to determine the progression rate of HSIL to invasive cancer. Although patients with good functional status and immunologic function seem to do relatively well with standard CMT for anal cancer, there are less fortunate patients who experience substantial morbidity from therapy and have a poorer outcome. It is difficult to draw definitive conclusions about the therapy of HIV-positive patients with anal cancer based on the available literature because of the retrospective nature of the analyses, the small number of patients, and the heterogeneity of the patients reported with regard to tumor size, pretreatment immunologic status, and the variety of treatments received by patients in some series. Identifying patients who develop invasive anal cancer as early as possible will improve results to some degree, but prospective, controlled, multi-institutional trials evaluating the treatment of anal cancer in HIV-infected persons are required to accurately define ways to improve outcome with less morbidity. The results of ongoing therapeutic HPV vaccine trials are eagerly awaited. Improvement may come by the following, determining ways to more accurately stage patients, such as endoanal ultrasound, sentinel lymph node sampling, or positron emission tomography scans; defining the role of cisplatin and whether it is indeed less toxic and equally or more effective; consideration of continuous protracted infusion of low-dose 5-FU; the optimum use of growth factors; and an evaluation of the role of conformal radiotherapy or the use of radio-protectants, such as amifostine. Meanwhile, the best way to treat anal cancer in HIV-infected persons may be to prevent it from occurring by screening persons at risk and treating HSIL, or at a minimum, following up patients carefully and detecting cancers, if they occur, at the earliest possible time.

Chemotherapy and radiation of anal canal cancer: the first approach

Since the late 1970's, increasing evidence from single-arm phase II studies has indicated that combined modality therapy yields a complete response rate of approximately 80-90% in most patients with squamous cell cancers of the anal canal. Surgery, most commonly an abdominoperineal resection, is reserved for salvage therapy. Although patients with large primary tumors (>5 cm) have a lower complete response rate of 50-75%, the majority of patients may be spared a colostomy and have an excellent overall survival. This chapter reviews the recent literature of patients treated for squamous cell, basaloid, and cloacogenic carcinoma (collectively defined as squamous cell cancer) of the anal canal.