A 2020 update of anal cancer: the increasing problem in women and expanding treatment landscape

ABSTRACT

Introduction

Anal cancer is a rare malignancy with increasing incidence, notably in women. This disease is highly associated with HPV infection and its incidence and mortality are currently rising. Most patients present with localized disease which has a high survival after definitive treatment with chemoradiation. For patients who develop metastatic disease or present with this de novo, survival is poor.

Areas covered

This review provides a summary of current literature on anal cancer. With a focus on women, this includes current epidemiological trends, role of HPV, and the current and future treatment landscape, including HPV vaccination and immunotherapy. Screening currently focusses on HIV-positive men, missing most female cases. In curative disease, trials are investigating treatment de-intensification in good prognostic groups. Immunotherapy is showing early promise in the advanced disease setting.

Expert opinion

Similar to cervical cancer, anal cancer is strongly associated with HPV, and therefore, broader implementation of screening programs may reduce its incidence. HPV vaccination is expected to reduce the development of (pre)malignant anal lesions. The emergence of biomarkers will assist patient treatment selection, allowing optimal balance of treatment efficacy and morbidity. It is hoped that new treatment approaches, including immunotherapy, will improve outcomes. International collaboration is needed.

KEYWORDS:

• Anal cancer
• chemoradiation
• HPV
• HPV carcinogenesis
• immunotherapy
• squamous cell carcinoma
• screening
• squamous intraepithelial lesions
• women

Article highlights

• Anal cancer incidence has been rising for 40 years. It is more common in women than men, apart from selected high-risk populations such as HIV co-infection.

• Squamous cell carcinoma is the predominant histology and strongly associated with HPV infection.

• Currently screening is not targeted towards women despite their significant disease burden.

• Chemoradiation remains the standard treatment in early disease, with surgical intervention reserved as salvage therapy.

• Morbidity for localized treatment has reduced with improved radiation techniques but the significant long-term quality of life impact remains.

• In the metastatic setting, survival remains poor. Newer treatment options such as immunotherapy are being evaluated with promising early results.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

Peer reviewers on this manuscript have no relevant financial relationships or otherwise to disclose.