Abstract 4204: Incidence of early-onset and average-onset colon cancer among Medicaid beneficiaries with and without HIV: a cohort study

Abstract Background: Colorectal cancer has increased among people living with HIV (PLWH). Studies have reported either no difference or lower risk of colorectal cancer incidence among PLWH as compared to the general population. We evaluated the incidence of colon cancer, both average-onset (diagnosed at 50 or older) and early-onset (diagnosed at less than 50), among a diverse population of people with and without HIV who have comparable sociodemographic factors and access to care. Methods: We obtained Medicaid Analytic eXtract (MAX) data from 2001-2015 for 14 states. We included 42,244,679 unique individuals with at least 7 months of continuous eligibility. HIV and colon cancer diagnoses were identified from inpatient and other non-drug claims. We used Cox proportional hazards regression models to assess the incidence of colon cancer, controlling for age, sex, race/ethnicity, calendar year of enrollment, state of enrollment, and number of comorbidities. Analyses were also adjusted for or stratified by age, sex, and race/ethnicity. Findings: We identified 191 colon cancer cases among 523,969 person-years among PLWH and 15,098 colon cancer cases among 63,579,078 person-years among beneficiaries without HIV. Colon cancer incidence increased with age among beneficiaries with and without HIV. Overall, HIV was modestly, inversely associated with colon cancer incidence (HR:0.84, 95%CI: 0.73, 0.98). PLWH 18-39 years old had increased hazard of colon cancer as compared to those without HIV (HR:1.67, 95%CI: 1.06, 2.65); this association was attenuated after adjustment for co-morbidities. HRs were null when early-onset colon cancer was assessed among all beneficiaries less than 50 years. PLWH had lower hazard of average-onset colon cancer compared to those without HIV (HR:0.81, 95%CI: 0.68, 0.96); this association was statistically significant among male, but not female, beneficiaries. Interpretation: Compared to beneficiaries without HIV, PLWH had a lower risk of average-onset colon cancer. PLWH had higher incidence of early-onset colon cancer, but this difference was attenuated after adjustment for comorbid conditions. Citation Format: Corinne Joshu, Keri Calkins, Jacqueline E. Rudolph, Xiaoqiang Xu, Eryka Wentz, Maneet Kaur, Filip Pirsl, Sally B. Coburn, Richard D. Moore, Bryan Lau. Incidence of early-onset and average-onset colon cancer among Medicaid beneficiaries with and without HIV: a cohort study. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 4204.