Strategies for Screening and Early Detection of Anal Cancers: A Narrative and Systematic Review and Meta-Analysis of Cytology, HPV Testing, and Other Biomarkers

Abstract

Anal cancer incidence and mortality have been increasing over the past decade. Although the incidence in the general population remains low, it is much higher in certain subgroups, including those living with human immunodeficiency virus and men who have sex with men. Approximately 90% of anal squamous cell cancers are caused by infection with carcinogenic human papillomavirus (HPV). Given the common etiology between anal and cervical carcinogenesis, screening for anal cancer has been proposed in certain high-risk populations using strategies adapted from cervical cancer prevention. In this review, the authors discuss important differences in anal and cervical cancer regarding the populations at risk, disease natural history, and clinical procedures and outcomes that need to be considered when evaluating strategies for anal cancer screening. They also performed a systematic review and meta-analysis of the performance of anal cytology, anal HPV testing, and various biomarkers for the detection of anal precancers and cancers. The implications of these performance estimates are summarized in the context of risk-based screening and management of anal precancers, and important research gaps are highlighted that need to be addressed to fully understand the benefits and harms of anal cancer screening. Cancer Cytopathol 2018;126:447-60. Published 2018. This article is a U.S. Government work and is in the public domain in the USA.