Prevalence and incidence of anal high-grade squamous intraepithelial lesions in a cohort of cisgender men and transgender women who have sex with men diagnosed and treated during acute HIV acquisition in Bangkok, Thailand

Abstract

Introduction: Men who have sex with men (MSM), especially those living with HIV, are at an increased risk of anal cancer. The prevalence and incidence of its precursor, anal high-grade squamous intraepithelial lesions (HSILs), among MSM who started antiretroviral therapy during acute HIV acquisition are yet to be explored.

Methods: Participants in an acute HIV acquisition cohort in Bangkok, Thailand, who agreed to take part in this study, were enrolled. All participants were diagnosed and started antiretroviral therapy during acute HIV acquisition. Human papillomavirus (HPV) genotyping and high-resolution anoscopy, followed by anal biopsy as indicated, were done at baseline and 6-monthly visits.

Results: A total of 89 MSM and four transgender women were included in the analyses. Median age at enrolment was 26 years. Baseline prevalence of histologic anal HSIL was 11.8%. With a total of 147.0 person-years of follow-up, the incidence of initial histologic anal HSIL was 19.7 per 100 person-years. Factors associated with incident anal HSIL were anal HPV 16 (adjusted hazards ratio [aHR] 4.33, 95% CI 1.03-18.18), anal HPV 18/45 (aHR 6.82, 95% CI 1.57-29.51), other anal high-risk HPV (aHR 4.23, 95% CI 1.27-14.14), syphilis infection (aHR 4.67, 95% CI 1.10-19.90) and CD4 count <350 cells/mm³ (aHR 3.09, 95% CI 1.28-7.48).

Conclusions: With antiretroviral therapy initiation during acute HIV acquisition, we found the prevalence of anal HSIL among cisgender men and transgender women who have sex with men to be similar to those without HIV. Subsequent anal HSIL incidence, although lower than that of those with chronic HIV acquisition, was still higher than that of those without HIV. Screening for and management of anal HSIL should be a crucial part of long-term HIV care for all MSM.

Keywords: HIV; early detection of cancer; highly active antiretroviral therapy; human papillomavirus viruses; precancerous conditions; sexual and gender minorities.