Initial Experience with Topical Fluorouracil for Treatment of HIV-Associated Anal Intraepithelial Neoplasia

Condyloma and Anal Dysplasia

Anal intraepithelial neoplasia (AIN) are precancerous lesions and are sequela of human papilloma virus (HPV) infection. AIN is classified as low-grade squamous intraepithelial lesion or high-grade squamous intraepithelial lesion. Screening with anal cytology and anoscopy should be considered for high-risk populations. Diagnosis is made through high resolution anaoscopy and biopsy. Options for treatment include ablation and several topical therapies; however, recurrence rates are high for all treatment options, and an ongoing surveillance is necessary to prevent progression to anal squamous cell carcinoma. HPV vaccination is recommended to prevent disease.

A phase I study of intra-anal artesunate (suppositories) to treat anal high-grade squamous intraepithelial lesions

BACKGROUND

Ablation or surgical excision is the typical treatment of anal high-grade squamous intraepithelial lesions (HSIL). Recurrences are common due to the persistence of underlying human papillomavirus (HPV) infection. Additional well-tolerated and effective non-surgical options for HPV-associated anal disease are needed.

METHODS

This 3+3 dose escalation Phase I clinical trial evaluated the safety and tolerability of artesunate suppositories in the treatment of patients with biopsy-proven HSIL.

RESULTS

The maximal tolerated dose was 400 mg, administered in 3 cycles. All adverse events associated with the use 200- and 400-mg artesunate suppositories were Grade 1. At the 600-mg dose, patients experienced clinically significant nausea.

CONCLUSION

Artesunate suppositories are a safe treatment option for anal HSIL.

Evaluating the efficacy of treatment options for anal intraepithelial neoplasia: a systematic review

PURPOSE

Anal intraepithelial neoplasia (AIN) is the accepted precursor of anal squamous cell carcinoma (ASCC). There has long been a hypothesis that treating AIN may prevent ASCC. Many different treatment modalities have been suggested and studied. We conducted this systematic review to evaluate their efficacy and the evidence as to whether we can prevent ASCC by treating AIN.

METHODS

MEDLINE and EMBASE were electronically searched using relevant search terms. All studies investigating the use of a single treatment for AIN that reported at least one end outcome such as partial or complete response to treatment, recurrence after treatment and/or ASCC diagnosis after treatment were included.

RESULTS

Thirty studies were included in the systematic review investigating 10 treatment modalities: 5% imiquimod, 5-fluorouracil, cidofovir, trichloroacetic acid, electrocautery, surgical excision, infrared coagulation, radiofrequency ablation, photodynamic therapy and HPV vaccination. All treatment modalities demonstrated some initial regression of AIN after treatment; however, recurrence rates were high especially in HIV-positive patients. Many of the studies suffered from significant bias which prevented direct comparison.

CONCLUSIONS

Although the theory persists that by inducing the regression of AIN, we may be able to reduce the risk of ASCC, there was no clinical evidence within the literature advocating that treating AIN does prevent ASCC.

Anal Intraepithelial Neoplasia and Squamous Cell Cancer of the Anus

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

Anal Dysplasia Screening and Treatment in a Southern Human Immunodeficiency Virus Clinic

BACKGROUND

Persistent human papillomavirus infection in human immunodeficiency virus (HIV)-infected individuals has been strongly associated with anal squamous cell carcinoma. The incidence of anal squamous cell carcinoma continues to increase in this population despite advances in HIV therapy. There are few studies describing the prevalence of anal cancer precursors, treatment outcomes, and associated factors among HIV-infected populations in the southern United States.

METHODS

A retrospective chart review was performed on 355 HIV-infected patients from a Southern HIV clinic who were 18 years or older and had received at least one anal Pap smear. Demographic and clinical variables were collected. Descriptive statistics, single variable, and multivariate logistic regression analysis were performed to evaluate for predictors of high-grade squamous intraepithelial lesion (HSIL). Odds ratios and 95% confidence intervals were constructed for independent measures.

RESULTS

After the first anal Pap smear, 38.3% (70/183) of patients with abnormal results were lost to follow-up. Comparing patients with biopsy proven HSIL versus low-grade squamous intraepithelial lesions, patients were less likely to have HSIL if they had a higher CD4 count (odds ratio, 0.81; 95% confidence interval, 0.72-0.93; P = 0.0022). Treatment success after the first round of treatment for topical and infrared coagulation therapy was 36.7% (18/49, all therapy types), and of those who achieved biopsy proven treatment success at follow-up screening, 94.4% (17/18) required subsequent therapy.

CONCLUSIONS

Patients with a higher CD4 count were less likely to have HSIL. CD4 nadir, number of sexual partners, and race/ethnicity were not significantly associated with the presence of HSIL.

Topical therapies for the treatment of anal high-grade squamous intraepithelial lesions

Anal cancer may be prevented by treating anal high-grade squamous intraepithelial lesions (HSIL). Ablative therapies are the most commonly used treatments, but they may not be appropriate for all patients including those with extensive HSIL or bleeding diastheses. Researchers have studied topical therapies for human papillomavirus related lesions including anal HSIL. These therapies include patient-applied 5-fluorouracil, imiquimod and cidofovir, and provider-applied trichloroacetic acid. This review will discuss literature supporting efficacy of these products, which is based mainly on case series with few controlled trials having been conducted. Side effects are common with patient-applied topical therapy often requiring dose reduction and medication to treat pain. However, treatment discontinuations are infrequent. This review will also discuss some approaches to the use of these products in clinical practice.

Phase I study demonstrates safety and tolerability of radiofrequency ablation (RFA) of the anal mucosa

BACKGROUND

Anal carcinoma is increasing in high-risk populations. Dysplasia is often distributed throughout the anal mucosa, and focal ablative techniques have high rates of recurrence.

METHODS

With the goal of eradicating dysplasia from the entire anal mucosa, we conducted a phase I dose-ranging study to determine the safety and tolerability of radiofrequency ablation (RFA). HIV-infected individuals with high-grade anal intraepithelial neoplasia underwent RFA of the anal mucosa. Patient-reported procedural and postprocedural symptoms were recorded, and mucosal healing was visually assessed.

RESULTS

Four groups of 3 subjects each were treated with incrementally increasing numbers of RF pulses (1-3) applied to a single area of anal mucosa. Two or three doses of 12 J/cm2 were found to have acceptable patient tolerance and healing of the mucosa within 4 weeks of ablation. Using these doses, 2 groups underwent ablation of 180° of contiguous mucosa. Subjects experienced a loss of 1 to 3 days of daily activities of living, 7 to 14 days of postprocedure symptoms, and mucosal healing within 4 weeks. One subject in the first treatment group had the procedure aborted due to severe procedural pain.

CONCLUSIONS

The study provides evidence of the safety and tolerability of anal RFA of 180° of contiguous mucosa in a single procedure and will allow future RFA efficacy studies in the treatment of anal dysplasia.

Current treatment options for management of anal intraepithelial neoplasia

Anal squamous cell cancer is an uncommon malignancy caused by infection with oncogenic strains of Human papilloma virus. Anal cancer is much more common in immunocompromised persons, including those infected with Human immunodeficiency virus. High-grade anal intraepithelial neoplasia (HGAIN), the precursor of anal cancer, is identified by clinicians providing care for patients with anorectal disease, and is increasingly being identified during screening of immunosuppressed patients for anal dysplasia. The traditional treatment for HGAIN has been excision of macroscopic disease with margins. This approach is effective for patients with small unifocal HGAIN lesions. Patients with extensive multifocal HGAIN frequently have recurrence of HGAIN after excision, and may have postoperative complications of anal stenosis or fecal incontinence. This led to the suggestion by some that treatment for HGAIN should be delayed until patients developed anal cancer. Alternative approaches in identification and treatment have been developed to treat patients with multifocal or extensive HGAIN lesions. High-resolution anoscopy combines magnification with anoscopy and is being used to identify HGAIN and determine treatment margins. HGAIN can then be ablated with a number of modalities, including infrared coagulation, CO2 laser, and electrocautery. These methods for HGAIN ablation can be performed with local anesthesia on outpatients and are relatively well tolerated. High-resolution anoscopy-directed HGAIN ablation is evolving into a standard approach for initial treatment and then subsequent monitoring of a disease which should be expected to be recurrent. Another treatment approach for HGAIN is topical treatment, principally with 5-fluorouracil or imiquimod. Topical therapies have the advantage of being nonsurgical and are well suited for treating widespread multifocal disease. Topical treatments have the disadvantage of requiring extended treatment courses and causing a symptomatic inflammatory response. Successful treatment requires adherence to a regime that is uncomfortable at best and at worst painful. Topical treatments can be successful in motivated adherent patients willing to accept these side effects.

Interventions for anal canal intraepithelial neoplasia

BACKGROUND

Anal canal intraepithelial neoplasia (AIN) is a pre-malignant condition of the anal canal transitional epithelium that is associated with human papillomavirus (HPV) infection. The incidence and prevalence of AIN and anal cancer are increasing rapidly in HIV-positive men who have sex with men (MSM). Other groups like HIV-negative MSM, immunosuppressed patients and people affected by other HPV diseases like genital warts and cervical intraepithelial neoplasia (CIN) may also develop AIN. The condition is complicated by its multicentric and multifocal nature and high rates of relapse and morbidity. Targeted excisions using ablative treatments such as cautery, infrared coagulation (IRC) and cryotherapy have been used as first-line therapeutic strategies, and there are many other options. There is no consensus about the optimal management of AIN.

OBJECTIVES

To evaluate the effects of therapeutic interventions for anal canal intraepithelial neoplasia (AIN).

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 4), MEDLINE and EMBASE (to October 2011). We also searched registers of clinical trials, abstracts of scientific meetings and reference lists of included studies, and contacted experts in the field and manufacturers of any AIN and HPV-specific treatments.

SELECTION CRITERIA

Randomized controlled trials (RCTs) that assessed any type of intervention for AIN.

DATA COLLECTION AND ANALYSIS

Two review authors independently abstracted data and assessed risk of bias. If it was possible, the data were synthesised in a meta-analysis.

MAIN RESULTS

We found only one RCT, which included 53 patients, that met our inclusion criteria. This trial reported data on imiquimod versus placebo. There was no statistically significant difference in the risk of disease cure but there was a trend for imiquimod to downgrade the AIN to a low-risk stage. The lack of statistical power of the trial may be due to the small number of patients in each group. The risk of bias was estimated as moderate.

AUTHORS' CONCLUSIONS

The included trial failed to demonstrate any statistically significant efficacy of imiquimod in the management of anal intraepithelial neoplasia (AIN). The absence of reliable evidence for any of the interventions used in AIN precludes any definitive guidance or recommendations for clinical practice. Prospective cohort studies and retrospective studies have not been included in this review as they are considered to provide lower quality evidence. Well designed RCTs are needed.

Therapy of human papillomavirus-related disease

This chapter reviews the current treatment of chronic and neoplastic human papillomavirus (HPV)-associated conditions and the development of novel therapeutic approaches. Surgical excision of HPV-associated lower genital tract neoplasia is very successful but largely depends on secondary prevention programmes for identification of disease. Only high-risk HPV-driven chronic, pre-neoplastic lesions and some very early cancers cannot be successfully treated by surgical procedures alone. Chemoradiation therapy of cervical cancer contributes to the 66-79% cervical cancer survival at 5 years. Outlook for those patients with persistent or recurrent cervical cancer following treatment is very poor. Topical agents such as imiquimod (immune response modifier), cidofovir (inhibition of viral replication; induction apoptosis) or photodynamic therapy (direct damage of tumour and augmentation of anti-tumour immunity) have all shown some useful efficacy (~50-60%) in treatment of high grade vulvar intraepithelial neoplasia (VIN). Provider administered treatments of genital warts include cryotherapy, trichloracetic acid, or surgical removal which has the highest primary clearance rate. Patient applied therapies include podophyllotoxin and imiquimod. Recurrence after "successful" treatment is 30-40%. Further improvements could derive from a rational combination of current therapy with new drugs targeting molecular pathways mediated by HPV in cancer. Small molecule inhibitors targeting the DNA binding activities of HPV E1/E2 or the anti-apoptotic consequences of E6/E7 oncogenes are in preclinical development. Proteasome and histone deacetylase inhibitors, which can enhance apoptosis in HPV positive tumour cells, are being tested in early clinical trials. Chronic high-risk HPV infection/neoplasia is characterised by systemic and/or local immune suppressive regulatory or escape factors. Recently two E6/E7 vaccines have shown some clinical efficacy in high grade VIN patients and this correlated with strong and broad systemic HPV-specific T cell response and modulation of key local immune factors. Treatments that can shift the balance of immune effectors locally in combination with vaccination are now being tested. This article forms part of a special supplement entitled "Comprehensive Control of HPV Infections and Related Diseases" Vaccine Volume 30, Supplement 5, 2012.