Prospective study of high grade anal squamous intraepithelial neoplasia in a cohort of homosexual men: influence of HIV infection, immunosuppression and human papillomavirus infection

The role of viral and bacterial pathogens in gastrointestinal cancer

The association of Helicobacter pylori (H. pylori) with gastric cancer is thus far the best understood model to comprehend the causal relationship between a microbial pathogen and cancer in the human gastrointestinal tract. Besides H. pylori, a variety of other pathogens are now being recognized as potential carcinogens in different settings of human cancer. In this context, viral causes of human cancers are central to the issue since these account for 10-20% of cancers worldwide. In the case of H. pylori and gastric cancer, as well as the human papillomavirus and anal cancer, the causal relationship between the infectious agent and the related cancer in the gastrointestinal tract has been clearly confirmed by epidemiological and experimental studies. Similarly, Epstein-Barr virus and the oncogenic JC virus are being suggested as possible causative agents for cancers in the upper and lower gastrointestinal tract. This review discusses various viral and microbial pathogens and their oncogenic properties in the evolution of gastrointestinal carcinogenesis and summarizes the available experimental data make a convincing agreement favoring the associations between infectious agents and specific human cancers.

Cost-utility analysis of screening high-risk groups for anal cancer

OBJECTIVES

Cost-utility analysis of screening for anal cancer in high-risk groups from a UK perspective.

METHODS

Criteria for the assessment of screening programmes were combined in a Markov model representing the natural history of anal cancer and HIV infection in the UK population of men who have sex with men (MSM). Alternative screening programmes were overlaid on the natural history model to evaluate their impact. The model was populated using data derived from a systematic review of the literature, and calibrated probabilistically to represent joint uncertainty in the input parameters.

RESULTS

Reference case results showed screening is unlikely to be cost-effective. Sensitivity analyses identified two important parameters: regression from low-grade anal intra-epithelial neoplasia (AIN) and utility effects. Increased AIN regression rates resulted in a minimum incremental cost per QALY gained of 39,405 pounds, whereas a best case scenario reduced the ratio to 20,996 pounds.

CONCLUSIONS

There are major areas of uncertainty. New analyses of existing primary data, undertaken specifically to inform regression rates may usefully update key parameters at little additional cost. If these analyses increase the likelihood that screening is cost-effective, further studies of the utility effects of treatment for high-grade AIN, and potential screening attendance rates may be justified.

Anal intraepithelial neoplasia in HIV infection

Human papillomavirus (HPV) infections belong to the most common sexually transmitted infections worldwide. While the immune system eliminates most HPV infections over time in immunocompetent individuals, HPV infections tend to persist in immunodeficient individuals. In HIV-infected men who have sex with men (MSM), anal HPV prevalence is more than 90% and infections with multiple HPV types are common. Consequently, HPV-associated anogenital malignancies occur with high frequency in patients with HIV infection. Anal intraepithelial neoplasia (AIN) is a potential precursor lesion of squamous cell carcinoma of the anus. Like its cervical counterpart, cervical intraepithelial neoplasia (CIN), AIN is causally linked to persistent infections with high-risk HPV types such as HPV16 or HPV18. As AIN and CIN share distinct biological similar-ities, AIN screenings analogous to Pap smear programs for CIN have been recommended in high-risk populations to reduce the incidence of anal carcinoma. These screenings include cytological analysis followed by high resolution anoscopy in case of anal dysplasia. Treatment guidelines for AIN are not yet available. Therapeutic strategies can be divided into topical (e.g. trichloroacetic acid, podophyllotoxin, imiquimod, photodynamic therapy) and ablative (e. g. surgical excision, laser ablation, infrared coagulation, electrocautery) measures. However, controlled studies on AIN treatment have not been performed. The impact of HPV vaccination on AIN development will also need to be assessed. Long-term follow-up of these patients is essential to gain more insight into the natural history of anogenital HPV infection in HIV-positive MSM.

Squamous dysplasia of the rectum in a patient with ulcerative colitis treated with 6-mercaptopurine

Human papilloma virus (HPV) has been found to be a precursor and risk factor for both cervical and anal dysplasia. Cervical dysplasia, which is the precursor to carcinoma, is associated with immunosuppression from a variety of causes; reports of anal dysplasia associated with immune suppression exist as well. A recent study published in abstract form only demonstrated that women with inflammatory bowel disease (IBD) had high rates of cervical dysplasia and that those on immune suppressants had even higher rates of dysplasia. We report a case of a 50-year-old woman with refractory ulcerative colitis chronically treated with 6-mercaptopurine that developed severe squamous dysplasia of the rectum. The dysplastic mucosa was found to be positive for p16 (associated with high-risk HPV) after immunostaining. A total colectomy was performed. This case highlights the importance of immune suppression in the development of dysplasia of the anus/cervix secondary to HPV infection.

Anal cancer: an overview

Anal cancer is a rare tumor with an incidence that has been rising over the last 25 years. The disease was once thought to develop as a result of chronic irritation, but it is now known that this is not the case. Multiple risk factors, including human papillomavirus (HPV) infection, anoreceptive intercourse, cigarette smoking, and immunosuppression, have been identified. HIV infection is also associated with anal cancer; there is a higher incidence in HIV-positive patients but the direct relationship between HIV and anal cancer has been difficult to separate from the prevalence of HPV in this population. HIV infection is also associated with anal cancer; there are increasing numbers of HIV-positive patients being diagnosed with the disease. Treatment of anal cancer prior to the 1970s involved abdominoperineal resection, but the standard of care is now concurrent chemoradiation therapy, with surgery reserved for those patients with residual disease. We present a case of anal cancer followed by a general discussion of both risk factors and treatment.

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.

Role of human papillomavirus in squamous cell metaplasia-dysplasia-carcinoma of the rectum

Primary colorectal squamous cell carcinoma (SCC) and squamous dysplasia are uncommon and little is known about their pathogenesis. Most have been reported in association with ulcerative colitis and other chronic disease states. Although cervical and anal SCC have been strongly linked to human papillomavirus (HPV) infection, the role of HPV in rectal squamous carcinoma has not been well-examined. We evaluated 3 cases of primary rectal SCC for the presence of high-risk HPV by immunohistochemistry for p16(INK4A), in situ hybridization, and polymerase chain reaction. HPV type 16 was detected by polymerase chain reaction in all cases. In addition, all cases exhibited diffuse strong reactivity for p16(INK4A) and punctate nuclear staining by Ventana HPVIII in situ hybridization. The presence of HPV 16 in all three cases suggests that high-risk HPV infection is a risk factor for rectal SCC, particularly in patients with underlying chronic inflammatory disease processes or altered immune status. Further studies are warranted to determine if SCC occurring more proximal in the colon are also HPV-dependent or occur via another, HPV-independent pathway.

Bilan préthérapeutique initial du carcinome épidermoïde invasif de l’anus

Anal epidermoid carcinoma is a rare malignant tumor, comprising less than 5% of all carcinomas of the colon, rectum, and anus. The primary therapy now includes radiotherapy, often in combination with chemotherapy. Radical surgery is now rarely indicated. Therapeutic indications are based on locoregional staging, the presence of visceral metastases and an evaluation of the medical history. Anorectal endosonography is helpful in evaluating locoregional extension. In addition, magnetic resonance imaging, positron emission tomography scanning and inguinal sentinel lymph node procedure should play a role in a more selective approach in patients with anal carcinoma.

Malignant progression of anal intra-epithelial neoplasia

BACKGROUND

Anal intra-epithelial neoplasia (AIN) is believed to be a precursor to squamous cell carcinoma of the anus. The risk of developing anal cancer in patients with AIN, although known to occur, has been thought to be relatively low. This study reviews our experience with AIN, reviewing the incidence and risk factors for development of invasive malignancy and the outcome of present management strategies.

METHODS

This study examined a cohort of 72 patients identified from a prospective database with AIN from a single institution between January 1996 and December 2004. A single pathologist examined all pathological specimens.

RESULTS

There were 72 patients (52 women) and the median age was 49 years (range, 18-81 years). We identified progression of AIN to invasive malignancy in eight patients despite undergoing surveillance. Regression following treatment or biopsy was seen in 25 patients. Four patients required stomas for incontinence following treatment.

CONCLUSION

This study has shown a high rate of progression to invasive malignancy (11%) with AIN despite surveillance. The patients at risk of developing squamous cell carcinoma were the immunocompromised and those with genital intra-epithelial field change. Treatment of AIN has significant complications and despite treatment, invasive cancers do occur. Decisions made for treatment of AIN can affect treatment choices if invasive malignancy develops.

Biology of HPV in HIV infection

HIV-positive men and women are at increased risk of anogenital and oral HPV infection. The risks for HPV-associated high-grade intra-epithelial neoplasia (IN) and cancer are also increased. The prevalence of oral, anal, and cervical HPV infection in HIV-positive individuals compared with HIV-negative individuals increases with progressively lower CD4+ levels, as does incident high-grade IN. In contrast to IN, development of cancer is not related to lower CD4+ level. With increasing grades of IN and cancer, the proportion of tissues with copy-number abnormalities (CNA) increases, with one of the most common genetic changes being amplification of chromosome 3q. The presence of CNA is associated with the integration of HPV DNA into the host genome, with loss of HPV E2 and/or E2 rearrangement. This suggests a link between CNA and increased HPV-induced chromosomal instability mediated through de-repressed E6 and E7 expression consequent to loss of functional E2 protein. In addition, epigenetic changes occur with increasing frequency in high-grade IN and cancer, such as hypermethylation leading to down-regulation of potential tumor suppressor genes. Analysis of these data together suggests that immune suppression plays a more prominent role in the earlier stages of HPV-associated disease, up to and including incident high-grade IN. Persistent high-grade IN and development of cancer may be more strongly related to the cumulative effect of HPV-associated genetic instability and the resulting host genetic changes. There are few data to suggest a direct role for HIV in the pathogenesis of HPV-associated neoplasia, but HIV-associated attenuation of HPV-specific immune responses may allow for persistence of high-grade IN and sufficient time for accumulation of genetic changes that are important in progression to cancer.

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.

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.

A population-based analysis of temporal trends in the incidence of squamous anal canal cancer in relation to the HIV epidemic

Squamous cell carcinoma of the anal canal (SCCA) is etiologically linked to human papillomavirus, and its incidence is increased among the immunosuppressed. We used data from the Surveillance, Epidemiology, and End Results program to analyze the incidence of SCCA in relation to 3 separate periods during the HIV epidemic: the pre-HIV era (1973-1981), the HIV era (1982-1995), and the highly active antiretroviral treatment (HAART) era (1996-2001). The incidence per 100,000 population of SCCA increased from 0.6 in the pre-HIV era to 0.8 in the HIV era and to 1.0 in the HAART era. The gap in SCCA incidence between women and men decreased from a ratio of 1.6:1 in the pre-HIV era to 1.5:1 in the HIV era and to 1.2:1 in the HAART era. There was a significant increase in incidence rates among men and women aged 30 to 54 years in the HAART era compared with the HIV era. Men were more likely to be diagnosed with early-stage disease, but they were less likely than women to receive radiation therapy. The incidence of SCCA has particularly increased among men and those between 30 and 54 years of age since the introduction of HAART.

Blind sampling is superior to anoscope guided sampling for screening for anal intraepithelial neoplasia

OBJECTIVES

Anal cytology smears are either collected "blind" (swab inserted 4 cm into anal canal and rotated) or guided through an anoscope (transformation zone visualised and then sampled). We compared these smear techniques with respect to sample quality and patient acceptability.

METHODS

Using a paired, random sequence clinical trial, 151 homosexual men (n = 95 HIV positive) underwent both smear techniques at a single visit; smear order was randomised and specimens were read blind. Both techniques utilised a Dacron swab, with water lubrication. Cytological specimens were prepared using a liquid based collection method (ThinPrep). The outcome measures were cytological specimen adequacy, cytological classification, presence of rectal columnar, squamous and metaplastic cells, contamination, patient comfort and acceptability, and volume of fluid that remained after the ThinPrep procedure.

RESULTS

Regardless of smear order, guided smears were less likely to detect higher grade abnormalities than blind smears (15 v 27 cases, p = 0.001). Controlling for smear order, guided smears were more likely to be assessed as "unsatisfactory" for cytological assessment (OR 6.93, 95% CI 1.92 to 24.94), and contain fewer squamous (OR 0.20, 95% CI 0.04 to 0.94) and metaplastic cells (OR 0.12, 95% CI 0.03 to 0.54) than blind smears; there were no other statistically significant differences between techniques. Regardless of smear technique, first performed smears were more likely to detect a higher grade abnormality than second performed smears (23 v eight cases, p < 0.001).

CONCLUSIONS

Blind cytology smears are superior to anoscope guided smears for screening for anal neoplasia in homosexual men.

High-resolution analysis of genomic alterations and human papillomavirus integration in anal intraepithelial neoplasia

Anal intraepithelial neoplasia (AIN) is the likely precursor to anal cancer. AIN is associated with human papillomavirus (HPV) infection, and HPV-associated genomic instability may play an important role in the progression of squamous intraepithelial neoplasia to cancer. Microarray-based comparative genome hybridization (aCGH) was performed on DNA from AIN specimens to determine the host genomic alterations and their correlation with HPV DNA integration or rearrangement. Of 27 high-grade AIN specimens tested by CGH, 8 (30%) showed regional DNA copy number abnormalities (CNAs). Five additional cases previously identified by chromosome CGH to carry CNAs were reanalyzed by aCGH and pooled with the 8 new cases for analysis. The most common regions of gain were on chromosome arms 1p, 1q, 3q, 8p, and 20q. The most common regions of loss were on chromosome arms 2q, 7q, 11p, 11q, and 15q. HPV16 DNA integration or rearrangement correlated with CNAs in host cell DNA (P = 0.007). Although aCGH can resolve amplicons at the 1- to 2-megabase (Mb) regional resolution, the most common alteration on chromosome 3 could only be resolved to a 75-Mb region from 3q21 to qtel. Our data suggest that there may be several oncogenes in this region that are coactivated to contribute to progression to high-grade AIN.

Length of human immunodeficiency virus disease and not immune status is a risk factor for development of anal carcinoma

BACKGROUND

The anal epithelium is subject to dysplastic change in patients with human immunodeficiency virus (HIV). We sought to determine if the duration of HIV disease or the patient's immune status were associated with the development of anal carcinoma.

METHODS

HIV-positive patients diagnosed with anal neoplasms were reviewed. Statistical analysis was performed via an unpaired Student t test and the Fisher exact test.

RESULTS

Fourteen patients were identified, 7 with anal intraepithelial neoplasms (group 1) and 7 with anal carcinoma (group 2). Human papillomavirus was detected in 100% of patients in group 1 and in 67% of patients in group 2. There was no significant difference in the level of immunosuppression as assessed by the CD4 counts (266.9 +/- 48.5 vs. 274.7 +/- 92.0 cell/c microl; P = .94) and viral loads (19,243 +/- 18,034 vs. 67,140 +/- 39,570 RNA/mL; P = .29) between groups 1 and 2, respectively. Group 2 had been HIV positive for a significantly longer period of time (12.6 +/- 2.3 y) compared with group 1 (5.9 +/- 2.0 y, P = .05).

CONCLUSIONS

The most significant factor for the development of invasive anal carcinoma in patients with HIV is duration of disease. As a result of improved long-term survival secondary to new HIV therapy, anal invasive carcinoma will become an increasing problem.

DNA methylation in anal intraepithelial lesions and anal squamous cell carcinoma

PURPOSE

Anal intraepithelial neoplasia is associated with human papillomavirus infection and may progress to invasive squamous cell carcinoma (SCC), which is increasing in immunocompromised patients. We hypothesize that anal intraepithelial neoplasia is associated with abnormal DNA methylation and that detection of these events may be used to improve screening programs.

EXPERIMENTAL DESIGN

Seventy-six patients were identified who underwent anal cytology screening and subsequent biopsy at our institution between 1999 and 2004. The specimens from these patients included 184 anal biopsies [normal, n = 57; low-grade squamous intraepithelial lesion (LSIL), n = 74; high-grade squamous intraepithelial lesion (HSIL), n = 41; and invasive SCC, n = 12] and 37 residual liquid-based anal cytology specimens (normal, n = 11; LSIL, n = 12; HSIL, n = 14). The methylation status of the following genes was determined for each biopsy and cytology sample using real-time methylation-specific PCR: HIC1, RASSF1, RARB, CDKN2A, p14, TP73, APC, MLH1, MGMT, DAPK1, and IGSF4.

RESULTS

Methylation-specific PCR analysis of biopsy samples revealed that DNA methylation was more common in SCC and HSIL than LSIL and normal mucosa. Specifically, methylation of IGSF4 and DAPK1 was prevalent in SCC (75% and 75% of cases, respectively) and HSIL (59% and 71%, respectively) but was absent in LSIL and normal biopsy samples. Methylation profiles of cytologic samples were similar to those found in the biopsy samples.

CONCLUSIONS

Aberrant DNA methylation is a frequent event in anal HSIL and SCC. Methylation of IGSF4 and DAPK1 is specific for HSIL and SCC, and may serve as a useful molecular biomarker.

Anal intraepithelial neoplasia in the highly active antiretroviral therapy era among HIV-positive men who have sex with men

OBJECTIVES

The incidence of anal cancer among men who have sex with men (MSM) has continued to increase since the introduction of highly active antiretroviral therapy (HAART). The prevalence of the putative anal cancer precursor, anal intraepithelial neoplasia (AIN) was high among HIV-positive MSM prior to the availability of HAART but little is known about AIN since HAART was introduced. We characterized the prevalence of AIN among HIV-positive MSM and examined the association between AIN and various factors including use of HAART.

DESIGN AND METHODS

A baseline point-prevalence analyses in a prospective cohort study of AIN was performed at a university-based research clinic. A total of 357 HIV-positive MSM with no history of anal cancer completed a questionnaire detailing behaviors and medical history, anal cytology and human papillomavirus (HPV) testing, and high-resolution anoscopy with biopsy for detection of AIN.

RESULTS

Eighty-one percent of participants with available CD4+ cell counts at baseline had AIN of any grade; 52% had AIN 2 or 3; and 95% had anal HPV infection. In multivariate analysis, detection of > or = 6 HPV types [odds ratio (OR), 36; 95% confidence interval (CI), 7.4-171) and use of HAART (OR, 10; 95% CI, 2.6-38) were associated with AIN after adjustment for length of time participants were HIV-positive, CD4+ cell count and HIV viral load.

CONCLUSIONS

The prevalence of AIN has remained high among HIV-positive MSM after the introduction of HAART. Our data indicate that HAART is not associated with a reduced prevalence of AIN and support measures to prevent anal cancer among HIV-positive MSM whether or not they are using HAART.

Management of anal canal cancer

PURPOSE

Chemoradiotherapy has replaced radical surgery as the initial treatment of choice for anal canal cancer. The roles of these therapeutic modalities are discussed and recommendations on management of anal canal cancer are made based on currently available evidence. Areas for further studies also are identified.

METHODS

Literature on management of anal canal cancer from January 1970 to July 2003 obtained via MEDLINE was reviewed. Reports on anal margin cancers were excluded.

RESULTS

Randomized, prospective, Phase 3 trials in Europe and the United States showed that chemoradiotherapy with 5-fluorouracil and mitomycin C was superior in local control, colostomy-free rate, progression-free survival, and cancer-specific survival compared with radiation alone. In larger tumors, the addition of mitomycin C to radiotherapy and 5-fluorouracil improves local control, colostomy-free, and disease-free survival but is associated with more acute hematologic toxicity. Chemoradiotherapy, including Cisplatin and 5-fluorouracil, appeared to be equal or superior to surgery as salvage therapy in patients with residual disease six weeks after initial nonsurgical treatment.

CONCLUSIONS

To improve treatment outcomes and reduce treatment-related toxicities, further studies are required to elucidate the optimal drug combination and doses, optimal radiation field, total dose, and fraction sizes. Randomized, multicenter trials are needed to define the treatment protocol that provides the highest rate of sphincter preservation with acceptable toxicity. Few studies addressed the treatment of metastatic disease, which remains a major cause of mortality.

Anal carcinomas in HIV-positive patients: high-dose chemoradiotherapy is feasible in the era of highly active antiretroviral therapy

BACKGROUND

Anal carcinoma, a common disease in HIV-positive patients, is usually treated with chemoradiotherapy. Generally tolerance was poor before the availability of highly active antiretroviral therapies. We report our experience of treating anal carcinoma in the era of new antiviral drugs.

PATIENTS AND METHODS

Between 1997 and 2001, nine men on highly active antiretroviral therapies with good immune status before chemoradiotherapy received concomitant chemoradiotherapy consisting of 5-fluorouracil and cisplatinum, and high-dose radiotherapy (60-70 Gy) for anal carcinoma. Six cancers were Stage I, two were Stage II, and one was Stage III. CD4+ cell counts were <200/ml for four patients, between 200/ml and 500/ml for four, and >500/ml for one.

RESULTS

All patients received the planned dose of radiation (> or = 60 Gy). The chemotherapy dose was reduced 25 percent in six patients. Overall treatment time was 58 days. Grade 3 hematologic or skin toxicity occurred in four patients. No association was observed between high-grade toxicity and CD4+ cell count. None of the patients developed opportunistic infections during follow-up. Eight patients were disease-free after a median follow-up of 33 months. Among them, four had no or minor anal function impairment at the last follow-up visit. One patient with T4N2 disease relapsed locally one year after treatment and underwent salvage abdominoperineal excision.

CONCLUSION

High-dose chemoradiotherapy for anal carcinomas is feasible with low toxicity in HIV-positive patients treated with highly active antiretroviral therapies. Local control is similar to that obtained for HIV-negative patients.

The value of anal cytology and human papillomavirus typing in the detection of anal intraepithelial neoplasia: a review of cases from an anoscopy clinic

BACKGROUND

Previous studies have reached differing conclusions about the utility of anal cytology as a screening tool for anal intraepithelial neoplasia (AIN). There is a need also to establish whether HPV typing offers a useful adjunct to screening.

METHODS

We analysed data from 99 consecutive homosexual/bisexual male patients (89 HIV-1 positive) who underwent high resolution anoscopy. Follow up visits for these patients were also included, giving a total of 160 anoscopic procedures. Comparison was made between results of anal cytology using the sampling method of Palefsky, and histological findings of biopsies taken from abnormal areas seen on high resolution anoscopic examination of the anal canal. Swabs taken concurrently with the cytology were analysed for the presence of human papillomavirus (HPV) DNA and compared with the cytological and histological findings.

RESULTS

The sensitivity of the cytology was 83%, and the specificity 38% when compared with histology. At screening of 34 asymptomatic men, 83% had anal cytological dysplasia and 78% had AIN. There were no significant differences in the prevalence of hrHPV genotypes between different cytological or histological grades of abnormalities.

CONCLUSION

Anal cytology by the Palefsky method is simple to undertake, has a sensitivity and specificity comparable with cervical cytology, and can therefore be used as the basis of a pilot screening project in centres with large cohorts of HIV positive homosexual men who have a high risk of developing anal carcinoma. HPV genotyping is not a useful adjunct to cytological screening.

Infrared coagulator: a useful tool for treating anal squamous intraepithelial lesions

PURPOSE

The incidence of invasive anal squamous carcinoma in men who have sex with men is rising, particularly in those with human immunodeficiency virus. As in the cervix the high-grade squamous intraepithelial lesion is thought to be an invasive squamous cell carcinoma precursor. Cervical high-grade squamous intraepithelial lesions are treated by removing the squamocolumnar transition zone. This is not possible in the anus, where treatment is often surgical and is accompanied by significant pain and morbidity. Better office-based techniques to treat anal high-grade squamous intraepithelial lesions are needed. We employed the infrared coagulator in an office setting to ablate high-grade squamous intraepithelial lesions.

METHODS

A retrospective review of medical records was performed on 68 human immunodeficiency virus-positive men who have sex with men who underwent infrared coagulator ablation of biopsy-proven high-grade dysplasia from the time we began using the procedure in 1999. All patients have had at least six months of follow-up. Procedures were performed with local anesthesia on patients with discrete high-grade squamous intraepithelial lesions. Follow-up consisted of anal cytology with high-resolution anoscopy and biopsy of suspicious areas every three to six months. New or recurrent high-grade dysplasia was retreated. Patients with circumferential or bulky disease were treated in the operating room and were excluded from the study.

RESULTS

Altogether, 68 patients met the enrollment criteria. The median patient age was 41 years (range 29-62 years). A total of 165 lesions were treated (mean 1.6 lesions, range 1-5) and only 46 (28 percent) persisted. However, 44 patients (65 percent) developed a new or persistent high-grade squamous intraepithelial lesion within a median time of 217 days (range 27-566 days) after infrared coagulation. The remaining 24 patients (35 percent) were free of high-grade dysplasia for a median of 413 days (range 162-1313 days) after infrared coagulation. When patients were treated a second or third time, the incidence of new or persistent high-grade dysplasia dropped to 58 percent and 40 percent, respectively. The probability of curing a retreated lesion was 72 percent. Using generalized estimating equations, the incidence of high-grade dysplasia decreased with repeated infrared coagulator treatments. No patient developed squamous-cell carcinoma, had a serious adverse event, or developed anal stenosis.

CONCLUSIONS

The infrared coagulator is a safe, office-based modality for treating anal high-grade squamous intraepithelial lesion in human immunodeficiency virus-positive men who have sex with men. Successive treatments led to decreased recurrence rates.

Increased Incidence of Squamous Cell Anal Cancer Among Men With AIDS in the Era of Highly Active Antiretroviral Therapy

OBJECTIVE

We sought to determine if the introduction of highly active antiretroviral therapy (HAART) corresponded with changes in anal squamous cell cancer rates among men with AIDS.

STUDY

We linked cancer registry data from 1988-2000 and AIDS registry data from 1981-July/2003 for San Diego County. We defined 1991-1995 and 1996-2000 as the pre- and post-HAART periods, respectively.

RESULTS

The annual incidence of invasive anal cancer increased from zero per 100,000 men with AIDS aged 25 to 64 years (95% confidence interval [CI], 0-226) in 1991 to 224 per 100,000 (95% CI, 102-425) in the year 2000. Pre-HAART, the average annual incidence of invasive anal cancer was 49 per 100,000 men with AIDS aged 25 to 64 years (95% CI, 16-114) versus 144 per 100,000 (95% CI, 93-212) post-HAART. The relative risk of invasive anal cancer among men with AIDS compared with men without known HIV/AIDS was 98 (95% CI, 36-264) pre-HAART and 352 (95% CI, 186-669) post-HAART. The increased incidence of anal cancer among men with AIDS resulted in an increase in the overall rate of anal cancer among men in San Diego County.

CONCLUSIONS

The rising incidence of anal cancer among men with AIDS may be related to increased longevity with HAART and the consequent increased time at risk for the development of malignancy and/or the result of greater use of cytologic screening.

Measurement Characteristics of Anal Cytology, Histopathology, and High-Resolution Anoscopic Visual Impression in an Anal Dysplasia Screening Program

BACKGROUND

The study aims were (1) to estimate agreement between consecutive anal cytologic examinations, between concurrent cytologic examination and histopathology, and between high-resolution anoscopy (HRA) visual impression and histopathology and (2) to estimate the prevalence of severe dysplasia by concurrent cytologic category.

METHODS

Prospective study of HIV-infected patients receiving anal dysplasia screening as part of routine care. Agreement between measures was estimated by weighted kappa-statistics.

RESULTS

Between July 2000 and September 2003, 1864 patients underwent 2947 anal cytology tests. Excluding unsatisfactory tests (6%), 642 patients had repeat cytologic evaluation and 154 had concurrent cytology tests and biopsy. Using 4-category cytology grading, kappa-agreement between the first 2 cytologic measurements was 0.36. Comparing concurrent cytology tests and biopsy, kappa-agreement was 0.36. Comparing the most severe HRA visual impression and biopsy, kappa-agreement was 0.32. The prevalence of anal intraepithelial neoplasia 3 at biopsy by concurrent cytology category was 0 (cytology normal), 21% (atypical squamous cells of uncertain significance), 27% (low-grade squamous intraepithelial lesion), and 54% (high-grade squamous intraepithelial lesion).

CONCLUSIONS

These data suggest that the reproducibility of key screening measures is moderate at best but of similar magnitude to that of other studies of anal and cervical dysplasia screening. As candidate interventions to treat or prevent precursor lesions enter clinical development, standardization and improvement of measurement methods are essential.

Anal Condyloma: A Comparison between HIV Positive and Negative Patients

HIV positive and negative patients with anal condylomata were compared to determine an association with squamous cell neoplasia, its disease progression, and response to treatment. From 1992 to 2003, 61 patients were diagnosed with anal condylomata by anal biopsy. Thirty-four patients were HIV+ and 27 patients were considered HIV-. Upon retrospective chart review, details on disease progression, development of malignancy, and subsequent treatment were collected. Sixty-one per cent of HIV+ patients had a neoplastic process in contrast to 25 per cent of HIV- patients ( P = 0.005). Five patients demonstrated disease progression, of which four were HIV+. Three HIV+ patients were treated for invasive carcinoma with excision and standard chemoradiation therapy. Two patients with T3 lesions developed recurrence and died. Eighteen HIV+ patients had noninvasive carcinoma and were treated with local excision without recurrence at mean follow-up of 28 months. HIV+ patients were shown to have more condylomata harboring squamous cell neoplasia than HIV- patients. Noninvasive carcinoma can be treated effectively with local excision, independent of HIV status; however, long-term follow-up is needed. Chemoradiation therapy in patients who are relatively healthy and have stage I disease may be successful. The role for chemoradiation in AIDS patients with stage III disease remains unclear.

Human papillomavirus, condylomata acuminata, and anal neoplasia

Genital human papillomavirus (HPV) infection is an increasingly common sexually transmitted disease. This virus causes condylomata acuminata and is associated with anal neoplasia. Management options are discussed.

Anal cancer incidence and survival: the surveillance, epidemiology, and end results experience, 1973-2000

BACKGROUND

Anal cancer is a rare malignancy of the anogenital tract that historically has affected women at a greater rate than men.

METHODS

The authors analyzed changing trends in incidence rates and 5-year relative survival percentages for patients with anal cancer. The publicly available data used in the current study were obtained from the Surveillance, Epidemiology, and End Results (SEER) Program, a system of population-based tumor registries in the United States.

RESULTS

The incidence of anal cancer was similar for men and women between 1994 and 2000 (2.04 per 100,000 and 2.06 per 100,000, respectively), the most recent period for which data were available, whereas men had lower rates than did women between 1973 and 1979 (1.06 per 100,000, compared with 1.39 per 100,000), the earliest period for which data were available. In addition, recently, black men had higher incidence rates than did other race-specific and gender-specific groups (2.71 per 100,000). From the earliest period for which data were available to the most recent period, relative 5-year survival improved from 59% to 73% among women, was unchanged among men ( approximately 60%), and decreased from 45% to 27% among black men. Eighteen percent of patients who had distant disease were alive at 5 years, compared with 78% of patients who had localized disease.

CONCLUSIONS

The incidence of anal cancer in the United States increased between 1973 and 2000, particularly among men. There were higher incidence rates and lower survival rates for black men compared with other race-specific and gender-specific groups. Later disease stage was inversely associated with the survival rate, indicating that earlier detection may improve the survival of patients with anal cancer.

Recent clinical trials summary

The current standard of care for the treatment of anal cancer as demonstrated by all of the completed phase 3 clinical trials remains 5-FU and mitomycin C in combination with radiation therapy. The basic elements of the approach outlined by Nigro have not changed in the last 30 years. Future phase 3 trials will serve to further perfect this approach and outline the role of HPV and dysplasia in the development and progression of this disease.

The etiology and epidemiology of anal cancer

The anatomic definitions for anal cancer (canal versus margin) are made based on the relationship of the tumor to the anal verge. This method had led to confusion for some providers. A modification in the terminology is proposed that includes intra-anal, perianal, and skin as categories. The cause of anal carcinoma remains to be fully elucidated, and HPV seems to play a central role in this process. The incidence of anal cancers has increased, which is related to the evolution of HIV and AIDS, and their treatment. The accurate pathologic analysis of anal tumors is complex and is significantly aided by close communication between clinician and pathologist.

Chapter 6: Immunosuppression and co-infection with HIV

Individuals with immunosuppression caused by HIV infection or organ transplantation are at increased risk of human papillomavirus (HPV)-associated anogenital cancers compared with age-matched healthy individuals. The exact role of immunosuppression in conferring increased risk is not known. Although it is unknown which stages of progression from dysplasia to cancer are most affected by immunosuppression, current data suggest that immunosuppression is most strongly associated with the early stages of dysplasia, and that progression to cancer per se is not associated with immunosuppression. Studies to determine this relationship in detail are hampered by the paucity of precise biomarkers of cell-mediated immune response to HPV. This chapter will address these and other issues to provide a better understanding of the biology of HPV infection among immunocompromised individuals. Questions remain about the biology of HPV infection among immunocompromised HIV-negative individuals (e.g., transplant patients) compared with those who are HIV-positive; the impact of highly active antiretroviral therapy on the natural history of anogenital dysplasia and cancer among those who are HIV-positive, and whether the biology of specific HPV types is the same in HIV-positive as in HIV-negative individuals. Understanding HPV infection in those who are immunocompromised offers the potential to better understand its pathobiology in the putatively immunocompetent host.

Angiogenesis in anal warts, anal intraepithelial neoplasia and anal squamous cell carcinoma

INTRODUCTION

Most cases of anal carcinoma seem to develop from high grade anal intraepithelial neoplasia (AIN) caused by persistent anal warts. Similar pre-invasive epithelial genital lesions (e.g. those of the cervix and vulva) have been shown to be associated with increased angiogenesis. In this study we examined biopsies of anal lesions ranging from warts to invasive anal carcinoma, with the aim of assessing the degree of angiogenesis in pre-invasive anal lesions.

METHOD

Samples from 70 patients (51 male) who had undergone excision biopsy or resection of anal wart lesions (20), low grade AIN (12), high grade AIN (27) and anal squamous cell carcinoma (SCC) (11) were studied. Samples (6) from normal HIV-anal skin were used as controls. The samples were stained for von Willebrand factor, a specific marker of endothelial cells. Angiogenesis was measured by microvessel density (MVD) analysis, quantifying the microvessels in the stroma adjacent to the epithelial lesion.

RESULTS

There was a statistically significant (P < 0.001) progressive increase in MVD between low grade AIN, high grade AIN and anal SCC. The difference in MVD between normal skin, warts and low grade AIN was not statistically significant.

CONCLUSION

There are progressive abnormal patterns of angiogenesis in highly dysplastic lesions, similar to those found in cervical and vulvar pathology. These findings may have biological, prognostic and therapeutic implications.

Anal cancer: an HIV-associated cancer

Although not yet included in the Centers for Disease Control definition of AIDS, anal cancer clearly occurs more commonly in HIV-infected patients. An effective screening program for those groups who are at highest risk might be expected to impact rates of anal cancer just as significantly as did cervical Pap screening programs for the incidence of cervical cancer. Despite a relatively low rate of progression from AIN to invasive cancer, the scope of the problem is enormous based on the prevalence of anal HPV infection and the size of the HIV-infected, at-risk population. Thus, the potential benefits of screening, detection, and the development of more effective therapy also are enormous. Currently, therapeutic HPV vaccines for AIN represent an exciting avenue of research in HPV-related anogenital disease. Invasive anal cancer and HSIL (which is believed to be the precursor lesion) are expected to become increasingly important health problems for both HIV-infected men and women as their life expectancy lengthens. Although HAART may have improved the ability of many to tolerate CMT, it appears that toxicity of this therapy continues to be a problem for a proportion of HIV-infected subjects. The acute side effects present specific challenges to the clinician and patient, have an immediate impact on the patient's plan of care and dose intensity of the treatment, and ultimately may impact the outcome of the planned treatment. Late toxicity may influence the long-term quality of life. Small patient numbers, variable radiation therapy doses, limited information about viral load, and a potential confounding effect of higher CD4+ levels make it difficult to draw any conclusions about the effect of HAART on anal cancer outcome. Large, prospective studies will be required before solid conclusions about the impact of various factors on anal cancer prognosis and outcome can be drawn.

Incidence of anal cancer in California: increased incidence among men in San Francisco, 1973-1999

BACKGROUND

Incidence of anal cancer has increased in the United States during the past 30 years. This report describes the incidence of this rare cancer in the diverse California population.

METHODS

Age-adjusted incidence rates (AAIR) were calculated by gender, race/ethnicity, county, and year of diagnosis for over 2100 cases of cancer of the anus diagnosed between 1995 and 1999. Age-adjusted incidence rates by time period 1973-1999 were calculated for San Francisco County.

RESULTS

Age-adjusted incidence was higher for women than for men (AAIR 1.5 vs 1.2) in California, but men under age 40 and those classified as non-Hispanic Black had higher rates than women, and men had higher rates in San Francisco County (AAIR=8.7). Rates were higher among non-Hispanic Blacks and Whites than among Hispanics and Asian/Pacific Islanders. For all of California, there was an average 2% annual increase among non-Hispanic White men between 1988 and 1999. Incidence of this cancer among White males residing in San Francisco County more than doubled between the 1984-1990 and 1996-1999 time periods. Rates rose especially dramatically for San Francisco men ages 40 to 64, from 3.7 cases per 100,000 in 1973-1978 to 8.6 cases per 100,000 in 1984-1990 and to 20.6 cases per 100,000 in 1996-1999.

CONCLUSIONS

Elevated incidence of anal cancer among White men residing in San Francisco County is likely to be related to the high proportion of men who have sex with men. Rates of anal cancer in this high-risk population increased during the past decade.

High prevalence of high risk human papillomavirus-capsid antibodies in human immunodeficiency virus-seropositive men: a serological study

BACKGROUND

Serological study of human papillomavirus (HPV)-antibodies in order to estimate the HPV-prevalence as risk factor for the development of HPV-associated malignancies in human immunodeficiency virus (HIV)-positive men.

METHODS

Sera from 168 HIV-positive men and 330 HIV-negative individuals (including 198 controls) were tested using a direct HPV-ELISA specific to HPV-6, -11, -16, -18, -31 and bovine PV-1 L1-virus-like particles. Serological results were correlated with the presence of HPV-associated lesions, the history of other sexually transmitted diseases (STD) and HIV classification groups.

RESULTS

In HIV-negative men low risk HPV-antibodies were prevailing and associated with condylomatous warts (25.4%). Strikingly, HIV-positive men were more likely to have antibodies to the high-risk HPV types -16, -18, -31, and low risk antibodies were not increased in a comparable range. Even those HIV-positive heterosexual individuals without any HPV-associated lesions exhibited preferentially antibody responses to the oncogenic HPV-types (cumulative 31.1%). The highest antibody detection rate (88,8%) was observed within the subgroup of nine HIV-positive homosexual men with anogenital warts. Three HIV-positive patients had HPV-associated carcinomas, in all of them HPV-16 antibodies were detected. Drug use and mean CD4-cell counts on the day of serologic testing had no influence on HPV-IgG antibody prevalence, as had prior antiretroviral therapy or clinical category of HIV-disease.

CONCLUSION

High risk HPV-antibodies in HIV-infected and homosexual men suggest a continuous exposure to HPV-proteins throughout the course of their HIV infection, reflecting the known increased risk for anogenital malignancies in these populations. The extensive increase of high risk antibodies (compared to low risk antibodies) in HIV-positive patients cannot be explained by differences in exposure history alone, but suggests defects of the immunological control of oncogenic HPV-types. HPV-serology is economic and can detect past or present HPV-infection, independently of an anatomical region. Therefore HPV-serology could help to better understand the natural history of anogenital HPV-infection in HIV-positive men in the era of antiretroviral therapy.

Topical cidofovir for the treatment of dermatologic conditions: verruca, condyloma, intraepithelial neoplasia, herpes simplex and its potential use in smallpox

Cidofovir is a new antiviral drug that has a broad spectrum of activity against several DNA viruses. Many of the disorders caused by these viruses do not have satisfactory therapy, and given the efficacy of this agent in treating many of these conditions, it holds great promise. It is hoped that ongoing studies will confirm the initial anecdotal reports regarding its therapeutic efficacy and lack of systemic side effects. It is also hoped that the cost to formulate and use cidofovir topically will eventually decrease to a level that will allow more widespread use of this drug.

Human papillomavirus infection and abnormal cytology of the anus in HIV-infected and uninfected adolescents

OBJECTIVE

To examine the prevalence of and risk for anal human papillomavirus (HPV) infection and abnormal anal cytology in sexually active adolescents.

DESIGN

Prevalence data from adolescents aged 13-18 years with and without HIV infection and with a history of high-risk sexual behavior.

METHODS

HPV DNA was detected using amplification techniques. Abnormal anal cytology was defined as atypical squamous cell of undetermined significance or worse.

RESULTS

Prevalence of anal HPV infection was similar in HIV-infected [28/58 (48%)] and uninfected [9/25 (36%)] boys (P = 0.3). but greater in HIV-infected [59/183 (59%)] than in uninfected [11/82 (13%)] girls (P < 0.001). Perianal warts were a risk for anal HPV in both boys [odds ratio (OR), 15.5; 95% confidence interval (CI), 1.6-149] and girls (OR, 9.9; 95% CI, 1.9-51.3). In subjects without anal warts, HIV infection was significant for girls (OR, 2.3; 95% CI, 1.1-4.9) and homosexual/bisexual orientation was significant for boys (OR, 5.2; 95% CI, 1.3-20.6). Abnormal anal cytology was more common among boys [32/77 (41.6%)] than girls [38/230 (16.5%)] (P < 0.001) and in addition to anal HPV, independent risk factors were positive HIV status in boys (OR, 6.5; 95% CI, 1.5-11.9) and number of partners within the past 3 months in girls (OR, 4.2; 95% CI, 1.5-11.9).

CONCLUSIONS

Strong risk factors for abnormal anal cytology were HIV infection and anal HPV in boys and anal HPV and higher number of sexual partners for girls. The results suggest that anal cytology screening should be considered in HIV infected homosexual/bisexual males.

Natural history and clinical management of anal human papillomavirus disease in men and women infected with human immunodeficiency virus

Before the introduction of highly active antiretroviral therapy (HAART), several studies demonstrated a high prevalence of human papillomavirus (HPV) infection and associated anal intraepithelial neoplasia (AIN) in men who have sex with men, particularly in human immunodeficiency virus (HIV)-infected men with low CD4+ cell counts. Similarly high levels of anal HPV infection and AIN have been found in HIV-positive women. HIV-positive men and women are at an increased risk of developing anal cancer compared with the general population. Data suggest that there has been no reduction in the incidence of AIN after the introduction of HAART. Screening efforts have the potential to decrease the incidence of invasive anal cancer, and cost-effectiveness analyses have demonstrated the utility of anal cancer screening in select populations. Treatment for AIN remains challenging, but AIN is easier to treat when the lesions are small, and it is likely that a screening program would identify affected individuals at an earlier stage of disease.

Cervical and anal HPV infections in HIV positive women and men

The goal of this review is to summarize recently published epidemiological information that contribute to understanding the natural history of cervical and human papillomavirus (HPV) infection and their associated lesions among human immunodeficiency virus (HIV) infected women and men. HIV-positive women and men are more likely to be infected with oncogenic HPV types and to have cervical intraepithelial neoplasia (CIN) or anal intraepithelial neoplasia (AIN), lesions that may lead to invasive cervical and anal cancer, respectively. Although the magnitude of the increased risk of cervical or anal cancer in HIV-positive individuals is not clear, it is clear that the risk will remain elevated even in the HAART era. Full screening for CIN remains necessary in HIV-positive women and it is likely that screening for AIN will be beneficial as well to prevent invasive anogenital cancer in long-term AIDS survivors.

External genital warts: diagnosis, treatment, and prevention

External genital warts (EGWs) are visible warts that occur in the perigenital and perianal regions. They are due primarily to non-oncogenic human papillomavirus (HPV) types, usually types 6 and 11. Physical examination assisted by bright light and magnification is the recommended approach for primary diagnosis. Biopsy is indicated when EGWs are fixed to underlying structures or discolored or when standard therapies are not effective. Recurrences are common, and there is no single treatment that is superior to others. Among women with atypical squamous cells, molecular HPV testing may be useful in determining who should be referred for colposcopy. Condoms may provide some protection against HPV-related diseases and thus are recommended in new sexual relationships and when partnerships are not mutually monogamous. Because the efficacy of cesarean section in preventing vertical transmission of HPV infection from women with EGWs to their progeny has not been proved, it is not recommended.

AIDS and non-AIDS-related malignancies: a new vexing challenge in HIV-positive patients. Part II. Cervical and anal squamous epithelial lesions, lung cancer, testicular germ cell cancers, and skin cancers

As the AIDS epidemic progresses, more and more HIV-infected patients will develop malignancies. The natural history of a malignancy may change dramatically in the presence of HIV infection. Among the AIDS and non-AIDS malignancies, the most frequently reported solid tumors are cervical and anal cancer, testicular germ cell tumors, lung cancer, and skin cancer. Regardless of epidemiology and outcome, the natural history of the majority of non-AIDS-defining tumors changes in the setting of HIV infection. Physicians who treat patients with AIDS and non-AIDS-related cancers need to become familiar with antiretroviral agents, drug-drug interactions, and the prophylaxis and management of opportunistic infections.