Comparing and contrasting clinical consensus and guidelines for anal intraepithelial neoplasia in different geographical regions

Abstract

Anal Squamous Cell Carcinoma (ASCC) is an uncommon cancer with a recognised precursor Anal Intraepithelial Neoplasia (AIN). Although there are consistent evidence-based guidelines for the management of ASCC, historically this has not been the case for AIN and as a result there have been geographical variations in the recommendations for the treatment of AIN. More recently there have been updates in the literature to the recommendations for the management of AIN. To assess whether we are now closer to achieving an international consensus, we have completed a systematic scoping review of available guidelines for the screening, treatment and follow-up of AIN as a precursor to ASCC. MEDLINE and EMBASE were systematically searched for available clinical guidelines endorsed by a recognised clinical society that included recommendations on either the screening, treatment or follow-up of AIN. Nine clinical guidelines from three geographical areas were included. The most recent guidelines agreed that screening for AIN in high-risk patients and follow-up after treatment was necessary but there was less consensus on the modality of screening. Six Guidelines recommended the treatment of high-grade AIN and four guidelines describe a follow-up protocol of patients diagnosed with AIN. There appears to be increasing consensus on the treatment and follow-up of patients despite a poor evidence base. There is still significant discrepancy in guidance on the method to identify patients at risk of ASCC and AIN despite consensus between geographical regions on which patient subgroups are at the highest risk.

Human Papillomavirus Genotypes Infecting the Anal Canal and Cervix in HIV+ Men and Women, Anal Cytology, and Risk Factors for Anal Infection

“…High-resolution anoscopy is considered the gold standard for the detection of anal cancer, and although official uniform international documents are lacking, several algorithms have been proposed [ 3 ]. Expert groups have established guidelines for defining standards for the detection of anal cancer precursor lesions, including the minimum requirements for anal cytology quality [ 34 , 35 ].…”

“…AIN is an infrequent pathology that has risen in incidence in the last few decades, with people living with HIV/AIDS being at higher risk [ 2 ]. Unlike cervical cancer and other HPV-related pathologies, AIN remains understudied, and there are no official international screening programs addressing the populations at risk [ 3 ]. The gold standard for diagnosis is high-resolution anoscopy; however, its availability is very limited in most settings [ 4 ].…”

Safety, feasibility, and short-term-outcome of anal endoscopic submucosal dissection for anal intraepithelial neoplasia: an option for focal lesions?

“…As mentioned above, international screening programs or guidelines for anal HPV infections and AIN are rare, although some national recommendations exist [ 20 ]. Even the strategies of screening (anal cytology for high risk HPV versus digital rectal examination with visual examination of the outer anal canal) are still a matter of debate, as is the cohort that is needed to be screened for AIN (HIV-positive patients, MSM patients) [ 21 , 22 ].…”

Update on the Epidemiological Features and Clinical Implications of Human Papillomavirus Infection (HPV) and Human Immunodeficiency Virus (HIV) Coinfection

“…Like the colposcopy procedure performed in cervical dysplasia screening programs, the anal mucosa can also be examined directly with an anoscope, and acetic acid impregnations may reveal areas of dysplasia. Treatment modalities include topical imiquimod, infrared coagulation, electrocautery, and surgical excision, according to the type of lesion [ 107 ]. The ANCHOR clinical trial recently compared intervention versus observation during anal dysplasia screening.…”