Abstract
Anal cancer is biological similar to cervical cancer, and is preceded by anal intraepithelial neoplasia (AIN). Screening for AIN and treatments to reduce the risk of anal cancer are not established as guidelines of care for HIV-infected patients. It is mainly because screening and treating of AIN is not yet proven to reduce the incidence of anal cancer. The present study preliminarily demonstrated that a successful screening program in preventing squamous cell anal cancer in HIV positive patients. The authors achieved their purpose of controlling the evolution of all abnormalities identified during the anal cancer screening, preventing AIN to progress towards anal cancer, and reversing any form of AIN by surgery, ablation or medical therapy. Randomized controlled multi-center trials with a large sample size should be carried out to validate the study results. It is wise for the physicians to actively screen and treat AIN in HIV-infected patients whenever possible unless the results of randomized controlled study demonstrate that doing so is inappropriate.
Anal cancer is uncommon in the general population with an annual incidence of 1.0∼1.5/100000 but it occurs much more frequently in HIV-infected patients [Citation1]. The incidence of anal cancer is 3.9∼30/100000 in HIV-infected women [Citation2]. It is even more commonly in MSM (men who have sex with men) with HIV (49.5/100000) [Citation3].
Anal cancer is biological similar to cervical cancer, and is preceded by anal intraepithelial neoplasia (AIN) [Citation4]. However, there is no standard management for AIN and this is mainly due to difficulties in both diagnosis and treatment. Using modalities and approaches adapted from cervical cancer prevention programs, AIN can readily be identified using screening modalities including digital rectal exam (DRE), anal Papanicolaou testing (Pap Test), human papilloma virus (HPV) co-testing, and high-resolution anoscopy (HRA). The goal is to provide histopathological confirmation and guiding therapy.
Screening for AIN and treatments to reduce the risk of anal cancer are not established as guidelines of care for HIV-infected patients. It is mainly because screening and treating of AIN is not yet proven to reduce the incidence of anal cancer. In the current article [Citation5], the authors reported their 5-year experiences of screening for anal cancer in HIV positive patients. Although the single center retrospective design has its inherent drawbacks, and the small sample size may mitigate the clinical significance of the results, this study preliminarily demonstrated that a successful screening program in preventing squamous cell anal cancer in HIV positive patients. The authors achieved their purpose of controlling the evolution of all abnormalities identified during the anal cancer screening, preventing AIN to progress towards anal cancer, and reversing any form of AIN by surgery, ablation or medical therapy. Randomized controlled multi-center trials with a large sample size should be carried out to validate the study results. Fortunately, such a study has already been initiated, known as the ANCHOR (Anal Cancer/HSIL Outcomes Research) study [Citation6]. This study will randomize more than 5000 HIV positive men and women with biopsy-proven anal AIN to treatment versus close observation for more than 5 years. If ANCHOR study demonstrates that AIN treatment significantly reduce the incidence of anal cancer, then screening program for anal cancer will become the standard of care for HIV-infected patients. Because results from the ANCHOR study are not available for the moment, it is wise for the physicians to actively screen and treat AIN in HIV-infected men and women whenever possible unless the ANCHOR study results demonstrate that doing so is inappropriate.
In summary, the implementation of anal cancer prevention services should be strongly considered in HIV-infected patients.
ACKNOWLEDGMENTS
Conflicts of Interest: no conflicts of interest. The authors alone are responsible for the content and writing of the paper.
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