EP484 - Evolving Demographics of Anal Squamous Cell Carcinoma: Younger Age and Lower Comorbidity Burden Among HIV-Positive Patients in South Florida

Purpose/Background: Anal squamous cell carcinoma (SCCA) incidence continues to rise in parallel with improved longevity among people living with HIV (PLWH), who remain at heightened risk due to persistent oncogenic HPV infection. Historically, PLWH were reported to present with advanced disease, higher treatment toxicity, and poorer outcomes. However, widespread antiretroviral therapy (ART) and immune restoration may be altering disease presentation and comorbidity profiles. Understanding how these trends manifest in high-prevalence regions is critical for guiding screening and management strategies. This study examines evolving demographic and comorbidity patterns among HIV-positive and HIV-negative patients with SCCA treated at a specialized center in South Florida, one of the nation's highest HIV-burden regions.

Methods/Interventions: A retrospective cohort study was conducted including patients aged ≥18 years diagnosed and treated for SCCA between 2015 and 2024. Demographic, clinical, and treatment data were extracted from medical records. Descriptive and comparative analyses were performed using chi-square and t-tests to evaluate differences in comorbidities, age at diagnosis, and treatment characteristics between HIV-positive and HIV-negative groups.

Results/Outcomes: Fifty-nine patients met inclusion criteria, of whom 21 (35.6%) were HIV-positive. HIV-positive patients were significantly younger at diagnosis (59 ± 7 vs. 67 ± 9 years, p=0.001). The overall cohort was predominantly White males, consistent with regional epidemiologic patterns. Despite similar BMI (25.9 ± 6 vs. 27.4 ± 5.9 kg/m², p=0.35), the HIV-positive cohort demonstrated a markedly lower prevalence of metabolic comorbidities, including hyperlipidemia (19% vs. 44.7%, p=0.04) and hypertension (33.3% vs. 36.8%, p=0.78). The burden of chronic kidney disease and coronary artery disease was also numerically lower among PLWH. Stage distribution and radiation dosing were comparable between groups. Treatment completion among HIV-positive patients was equivalent to that of HIV-negative patients (90.4% vs. 73.6%, p=0.09), with no statistically significant differences in recurrence (19% vs. 15.7%, p=0.39) or survival (90.4% vs. 94.7%, p=0.53).

Conclusion/Discussion: In this high-prevalence South Florida cohort, HIV-positive patients with SCCA presented nearly a decade earlier and with a lower burden of cardiometabolic comorbidities than HIV-negative counterparts, suggesting a distinct and evolving clinical phenotype. These findings imply that effective ART and regular follow-up may mitigate systemic comorbidity accumulation and facilitate earlier cancer detection within the HIV population. Comparable treatment completion and survival between groups underscore the impact of modern HIV management, while persistent disparities in epidemiologic patterns highlight the importance of targeted screening, HPV vaccination, and prevention strategies in younger, predominantly male HIV-positive populations. Larger multicenter studies are warranted to validate these regional trends and inform tailored public health interventions.

Table 1. Demographic, clinical characteristics and outcomes compared between HIV-positive and HIV-negative patients diagnosed and treated for SCCA