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World J Exp Med. Sep 20, 2024; 14(3): 98525
Published online Sep 20, 2024. doi: 10.5493/wjem.v14.i3.98525
Anal carcinoma - exploring the epidemiology, risk factors, pathophysiology, diagnosis, and treatment
Kevan J English
Kevan J English, Department of Medicine, Division of Gastroenterology & Hepatology, Saint George’s University School of Medicine, Saint George 33334, Saint George, Grenada
Author contributions: English KJ wrote the original draft, contributed to conceptualization, writing, reviewing, and editing of the manuscript; The author read and approved the final version of the manuscript.
Conflict-of-interest statement: The author reports no relevant conflicts of interest for this article.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Kevan J English, MD, Doctor, Research Scientist, Department of Medicine, Division of Gastroenterology & Hepatology, Saint George’s University School of Medicine, University Centre, Saint George 33334, Saint George, Grenada. kenglish@sgu.edu
Received: June 28, 2024
Revised: July 15, 2024
Accepted: August 6, 2024
Published online: September 20, 2024
Processing time: 61 Days and 23.8 Hours
Abstract

Anal carcinoma is a relatively rare tumor that accounts for approximately 2% of gastrointestinal malignancies and less than 7% of anorectal cancers. Most anal tumors originate between the anorectal junction and the anal verge. Risk factors for the disease include human papillomavirus infection, human immunodeficiency virus, tobacco use, immunosuppression, female sex, and older age. The pathogenesis of anal carcinoma is believed to be linked to human papillomavirus-related inflammation, leading to dysplasia and progression to cancer. Squamous cell carcinoma is the most common type of anal tumor, with an annual incidence of approximately 1 to 2 per 100000 persons. Treatment regarding anal cancer has emerged over time. However, chemoradiation therapy remains the mainstay approach for early localized disease. Patients with metastatic disease are treated with systemic therapy, and salvage surgery is reserved for disease recurrence following chemoradiation. This article aims to provide background information on the epidemiology, risk factors, pathology, diagnosis, and current trends in the management of anal cancer. Future directions are briefly discussed.

Keywords: Anal cancer; Squamous cell carcinoma; Chemoradiation therapy; Human papillomavirus; Immunosuppression

Core Tip: Anal cancer is a rare malignancy, comprising 1%-6% of anorectal tumors. The incidence of anal carcinoma has been steadily increasing worldwide, and diagnosis is often challenging due to the similarities in clinical presentation to benign rectal diseases such as hemorrhoids. Roughly 85% of anal cancers are squamous cell carcinoma, and human papillomavirus infection and immunosuppression are major risk factors for the disease. Chemoradiation is the treatment of choice for early-stage cancer, while systemic therapy is used for metastatic disease. Novel cytotoxic agents in combination with immunotherapy have produced favorable outcomes in patients with advanced disease.