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

Anal cancer is an uncommon malignancy, comprising only 2.5% of all gastrointestinal malignancies and similar to cervical cancer, the human papillomavirus (HPV) is responsible for the majority of anal cancers. Over the last decades there has been an up to 3-fold increased incidence seen in specific populations at risk such as persons living with HIV (PLWH), men who have sex with men (MSM), woman diagnosed with HPV-related gynaecological precancerous lesions or cancer, solid organ transplant recipients (SOTR) and patients with autoimmune diseases. Although international practice is evolving increasingly towards active screening for and treatment of anal cancer precursors in at-risk groups, currently no organised screening program is in effect in Belgium. Currently, differerent screening options as well as treatment modalities are available. Before commencing a nationwide organised screening program, essential decisions on screening strategies need to be made, based on both scientific as well as financial and logistical facts.