The importance of anal cancer screening and high-resolution anoscopy to gastroenterology practice

Abstract

Purpose of review Although human papillomavirus (HPV)-related anal squamous cell cancer (ASCC) is rare, its incidence has been rising and in high-risk populations exceeds the incidence of cancers for which screening programs are implemented. Therefore, targeted screening techniques are being evaluated with high-resolution anoscopy (HRA) as the current gold standard because of its ability to detect anal intraepithelial dysplasia (AIN) and premalignant high-grade squamous intraepithelial lesions (HSILs). However, a scarcity of trained providers presents a barrier to screening. Recent findings ASCC incidence is rising especially in elderly women and young black men. Premalignant HSIL may not only progress to ASCC but also regress. Biomarkers such as HPV type, p16 immunostaining and DNA methylation markers may emerge as predictors of disease progression. HRA with acetic acid and Lugol's iodine staining can be used to detect HSIL and ASCC. Recent studies suggest that anal cancer screening may have an impact on the stage of ASCC at diagnosis and the incidence of anal cancer. The Anal Cancer HSIL Outcomes Research (ANCHOR) study is underway to determine whether treating HSIL effects ASCC incidence. Summary Although there are no consensus screening guidelines for anal cancer, it is reasonable to screen high-risk populations with physical examination, anal cytology and HRA. Gastroenterologists can support anal cancer screening programmes through identifying patients at risk, performing noninvasive screening and considering to incorporate endoscopic techniques to examine the anal canal. Video abstract http://links.lww.com/COG/A32.

Case report: a precancerous lesion associated with HPV in the anal canal diagnosed by magnifying endoscopy with narrow-band imaging and resected by endoscopic submucosal dissection

“…There have been several case reports on the use of colonoscopy in the diagnosis and treatment of early cancer of the anal canal ( 12–15 ), but there is only one case report on the endoscopic diagnosis and treatment of anal HSIL ( 16 ), and it did not involve the association between anal canal HSIL and HPV infection. Histopathologic changes of lower anogenital squamous lesions are reported on the basis of a two-tiered system (The Lower Anogenital Squamous Terminology, LAST): a low-grade (LSIL) or high-grade (HSIL) squamous intraepithelial lesion ( 17 ) and the immunostaining of P16 is a biomarker for HPV-related precancerous lesions ( 11 ). The positive P16 immunostaining has been found to predict LSIL to HSIL progression and further to become SCC ( 17 ).…”

“…Histopathologic changes of lower anogenital squamous lesions are reported on the basis of a two-tiered system (The Lower Anogenital Squamous Terminology, LAST): a low-grade (LSIL) or high-grade (HSIL) squamous intraepithelial lesion ( 17 ) and the immunostaining of P16 is a biomarker for HPV-related precancerous lesions ( 11 ). The positive P16 immunostaining has been found to predict LSIL to HSIL progression and further to become SCC ( 17 ). Rates of progression of HSIL to anal SCC varied by population and risk factors, and estimates of 5-year anal SCC risk after HSIL diagnosis ranged from 3 to 32% ( 18 ).…”

Diagnosis and screening for anal intraepithelial neoplasia in Belgium: position statement

“…hemorrhoidectomy specimen). Local screening initiatives also include referring asymptomatic HIV-HRA (51,57). The interval for screening in patients at lower risk, defined as normal cytology and HPV16negative at baseline, can potentially be increased to 3 years although there is poor quality of evidence at present to guide ideal follow-up protocols (58).…”

Lesiones precursoras del cáncer anal en la mujer: abordaje desde la óptica del ginecólogo

“…Para los médicos ginecobstetras es relevante advertir a las pacientes sobre esta posibilidad y reconocer la necesidad de ampliar el horizonte del exámen clínico ginecológico anual de manera que la evaluación del área perianal sea rutinaria y se conozca la utilidad de las diferentes alternativas de tamizaje de la NIA. Vale la pena recordar que las pruebas más usadas en la literatura para la tamización y el diagnóstico de NIA son la citología anal, reportada con el sistema Bethesda, junto con el examen digital ano-rectal (en inglés conocido por el acrónimo DARE) (12) y la anoscopia de alta resolución (13). Además, se requiere que en las unidades de patología del tracto genital inferior y colposcopia se considere la conformación de grupos multidisciplinarios para el diagnóstico y la atención de las mujeres con la patología premaligna del tracto genital inferior que incluye a la NIA.…”