Treatment of anal high-grade squamous intraepithelial lesions can reduce rates of progression to invasive anal cancer.

1. The rate of progression was 57% lower in the group receiving anal HSIL treatment as compared to the group receiving active monitoring only.

2. Lesions greater than 50% of the anal canal/perianal region were more likely to progress to anal cancer than lesions smaller than 50% of the same region.

Evidence Rating Level: 1 (Excellent)

Study Rundown: Human papillomavirus (HPV) is responsible for both cervical and anal cancers and HIV patients are at high risk. While treatment for high-grade squamous intraepithelial lesions (HSILs) has been shown to reduce progression to cervical cancer, data regarding treatment of anal HSILs is minimal. This study aimed to compare the outcome of HSIL treatment vs. active monitoring on the rate of progression to anal cancer of adult individuals who had anal HSIL with HIV. Treatment options included ablation or excision, electrocautery, infrared coagulation, topical fluorouracil, or topical imiquimod. Secondary outcomes included the safety profile of anal HSIL treatment options. Fewer participants who received anal HSIL treatment progressed to anal cancer than those who received active monitoring (173 per 100,000 person years vs. 402 per 100,000 person years, respectively). Participants with a lesion size greater than 50% of the anal canal or perianal region were more likely than those with HSIL less than 50% to have progression to anal cancer (1047 per 100,000 person-years vs. 185 per 100,000 person years). Serious adverse events (AEs) related to interventions occurred in 7 participants in the treatment group, whereas only 1 occurred in the active-monitoring group. While there were 55 deaths in the treatment group and 48 in the active monitoring group, none were considered to be related to trial interventions. Limitations to this study include the applicability to patients under the age of 35 as participants in this trial were 35 years or older. Additionally, the results obtained in this trial may not be replicable if both high-resolution anoscopy and treatment are completed by less experienced and trained clinicians. Overall, treatment can reduce the progression to anal cancer in patients with biopsy-proven anal HSIL as compared to active monitoring.

Click to read the study in The New England Journal of Medicine

Relevant Reading: What Is the Risk of Anal Carcinoma in Patients With Anal Intraepithelial Neoplasia III?

In-Depth [ randomized controlled trial]: This multi-centre, phase 3 randomized, controlled trial included 4,446 participants (2,227 in the HSIL treatment group and 2,219 in the active monitoring group) in the analysis of progression to anal cancer and safety profile outcomes. Inclusion criteria included adult HIV patients 35 years and older who had biopsy-proven anal HSIL. In the HSIL treatment group, 9 participants had progression to anal cancer as compared to 21 participants from the active monitoring group. The rate of progression in the treatment group was 173 per 100,000 person-years (95% confidence interval (CI), 90 to 332) compared to 402 per 100,000 person-years in the active monitoring group (95% CI, 262 to 616). The rate of progression was lower in the group receiving anal HSIL treatment by 57% (95% CI, 6 to 80). The size of the HSIL was associated with the time to progression to anal cancer (hazard ratio (HR), 5.26; 95% CI, 2.54 to 10.87). Lesions greater than 50% of the anal canal/perianal region were more likely to progress to anal cancer than lesions smaller than 50% of the same region (cancer (1047 per 100,000 person-years vs. 185 per 100,000 person years). AEs attributable to interventions occurred in 7 participants in the treatment group, but only in 1 participant in the active-monitoring group. There were no deaths related to trial interventions, though there were 55 deaths in the treatment group and 48 in the active monitoring group.

Image: PD

©2022 2 Minute Medicine, Inc. All rights reserved. No works may be reproduced without expressed written consent from 2 Minute Medicine, Inc. Inquire about licensing here. No article should be construed as medical advice and is not intended as such by the authors or by 2 Minute Medicine, Inc.