The Diagnostic and Therapeutic Challenge of Anal Intraepithelial Neoplasia
- 192 Downloads
Purpose of Review
No single modality of care serves as the defined best practice for the treatment of anal intraepithelial neoplasia (AIN). This review aims to present the common treatment modalities germane to AIN while considering evolving evidence.
AIN affords an opportunity to evaluate and treat patients before the development of invasive diseases. Efforts to screen for AIN have yielded mixed results. The major available pharmacotheraputic and surgical options offer efficacious options to reduce the bioburden of disease but can be met with high levels of recurrent disease. None affords a predictably durable response in severe disease.
Vaccination as primary prevention will likely reduce the overall upward trend in AIN. Evidence suggests vaccination also affords improvement in recurrent disease. Early evidence reveals potential benefit in multimodal approaches to control AIN. Valuable data is anticipated from the phase III, randomized ANCHOR study evaluating the management of high-grade AIN in HIV +patients.
KeywordsAIN Anal intraepithelial neoplasia HPV Human papilloma virus
Compliance with Ethical Standards
Conflict of Interest
The authors declare that they have no conflict of interest.
Human and Animal Rights and Informed Consent
This article does not contain any studies with human or animal subjects performed by any of the authors.
Papers of particular interest, published recently, have been highlighted as: • Of importance •• Of major importance
- 5.Centers for Disease Control and Prevention. 2017. Genital HPV infection-fact sheet. Available at: http://www.cdc.gov/hpv/parents/questions-answers.html. Accessed 12, 2017.
- 10.American Cancer Society. Cancer Facts & Figures 2017. Atlanta, GA: American Cancer Society; 2017. Available at https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2017. Accessed 10 Nov 2017.
- 11.American Cancer Society. Cancer Facts & Figures 2010. Atlanta, GA: American Cancer Society; 2010. Available at https://www.cancer.org/research/cancer-facts-statistics/all-cancer-facts-figures/cancer-facts-figures-2017. Accessed 10 Nov 2017.
- 12.Nayar R, Wilbur D. The Bethesda system for reporting cervical cytology. 3rd ed. New York: McGraw-Hill; 2015.Google Scholar
- 13.• Steele SR, Varma MG, Melton GB, Ross HM, Rafferty JF, Buie WD. Standards Practice Task Force of the American Society of Colon and Rectal Surgeons. Practice parameters for anal squamous neoplasms. Dis Colon Rectum. 2012;55(7):735–49. A comprehensive evidence-based review compiled and updated by ASCRS, designed to guide the practice of surgeons treating anal squamous neoplasms. CrossRefPubMedGoogle Scholar
- 15.Panther LA, Wagner K, Proper J, Fugelso DK, Chatis PA, Weeden W, et al. High resolution anoscopy findings for men who have sex with men: inaccuracy of anal cytology as a predictor of histologic high-grade anal intraepithelial neoplasia and the impact of HIV serostatus. Clin Infect Dis. 2004;38(10):1490–2.CrossRefPubMedGoogle Scholar
- 18.• Richel O, Hallensleben ND, Kreuter A, van Noesel CJ, Prins JM, de Vries HJ. High-resolution anoscopy: clinical features of anal intraepithelial neoplasia in HIV-positive men. Dis Colon Rectum. 2013;56(11):1237–42. Good paper describing high risk lesions seen with HRA, helpful color pictures. CrossRefPubMedGoogle Scholar
- 20.Grillo-Ardila CF, Angel-Müller E, Salazar-Díaz LC, Gaitán HG, Ruiz-Parra AI, Lethaby A. Imiquimod for anogenital warts in non-immunocompromised adults. Cochrane Database Syst Rev. 2014;(11):CD010389. https://doi.org/10.1002/14651858.CD010389.pub2.
- 21.Fox Paul A, Mayura N, Nicholas F, Naveena S, Justin W, Glen D, et al. A double-blind, randomized controlled trial of the use of imiquimod cream for the treatment of anal canal high-grade anal intraepithelial neoplasia in HIV-positive MSM on HAART, with long-term follow-up data including the use of open-label imiquimod. AIDS. 2010;24(15):2331e5.Google Scholar
- 24.Richel O, de Vries HJC, van Noesel CJM, Dijkgraaf MGW, Prins JM. Comparison of imiquimod, topical fluorouracil, and electrocautery for the treatment of anal intraepithelial neoplasia in HIV-positive men who have sex with men: an open-label, randomised controlled trial. The Lancet Oncology. 2013;14(4):346–53.CrossRefPubMedGoogle Scholar
- 30.•• Goldstone SE, Johnstone AA, Moshier EL. Long-term outcome of ablation of anal high-grade squamous intraepithelial lesions: recurrence and incidence of cancer. Dis Colon Rectum. 2014;57(3):316–23. Very large retrospective review showing the safety and efficacy of multiple ablative techniques. CrossRefPubMedGoogle Scholar
- 33.• Richel O, de Vries HJ, van Noesel CJ, et al. Comparison of imiquimod, topical fluorouracil, and electrocautery for the treatment of anal intraepithelial neoplasia in HIV-positive men who have sex with men: an open-label, randomised controlled trial. Lancet Oncol. 2013;14:346–53. One of the only randomized trials published to date comparing topical vs ablative therapies for AIN. Small and single institution but well done. CrossRefPubMedGoogle Scholar
- 38.•• AIDS Malignancy Consortium. ANCHOR Study: Anal Cancer/HSIL Outcomes Research Study. ClinicalTrials.gov Identifier: NCT02135419. This ongoing trial will provide by far the best evidence to date regarding management and surveillance of high-grade AIN.
- 41.• Swedish KA, Factor SH, Goldstone SE. Prevention of recurrent high-grade neoplasia with quadrivalent human papillomavirus vaccination of men who have sex with men: a nonconcurrent cohort study. Clin Infect Dis. 2012;84(7):891–8. A quality retrospective review displaying efficacy of HPV vaccination in reducing HGAIN recurrence after treatment. CrossRefGoogle Scholar