Analysis of >15 000 Solid Organ Transplant Recipients Reveals Nonanal Genitourinary HPV-related Disease as Highest Risk Predictor for Anal Squamous Intraepithelial Lesions/Anal Cancer

Abstract

Background: Solid organ transplantation is a risk predictor for virally-mediated anal squamous intraepithelial lesions and cancer (anal disease). Precancerous squamous intraepithelial lesions can be detected by screening, and treatment may prevent cancer progression. Screening recommendations are not well defined. We aim to define prevalence and describe risk predictors for anal disease in a large population of solid organ transplant recipients.

Methods: Retrospective single-center cohort analysis included solid organ transplant recipients cared for between 2001 and 2022 (N = 15 362). The cohort of recipients who developed anal disease was compared with those who did not. Greedy propensity score matching was performed for organ-specific recipients, and time-to-event analysis for the development of anal disease was performed in those with genitourinary human papilloma virus (HPV) disease versus those without.

Results: Prevalence of anal disease was 0.6% (cancer 0.2%). The average years from transplant to the diagnosis of anal disease was 11.67. Anal disease was more common in women (68.5% versus 31.5%, P < 0.001), patients who had other HPV-related genitourinary diseases (40.4% versus 0.6%, P < 0.001), who were of younger age at transplant (39.62 versus 46.58, P < 0.001), and had increased years from transplant (17.06 versus 12.57, P < 0.001). In multivariate analysis, the odds of anal disease increased by 4% each year posttransplant. History of genitourinary HPV disease (odds ratio 69.63) and female sex (odds ratio 1.96) were the most significant risk predictors for anal disease.

Conclusions: The prevalence of anal cancer among solid organ transplant recipients was equal to the general population (0.2%). Due to the low prevalence of overall disease, these data suggest that anal screenings in transplant recipients should be targeted to higher-risk subsets: female recipients farther out from transplant and patients with genitourinary HPV-related diseases.

Figure 1:

Transplanted organ type distribution for respective anal disease progression categories (Condyloma/Low-Grade [LSIL], High-Grade [HSIL], Anal Cancer) among all anal disease patients.

Figure 2:

Development of anal disease over time for patients with other non-anal GU HPV diagnosis versus those without. “+” represents data censored based on patients lost to follow-up or death. Date of transplant is starting timepoint for all patients.