Trends and Predictors of Hematopoietic Cell Transplant Utilization for HIV-lymphoma in California, 1991-2016

Hematopoietic cell transplant (HCT) is a potentially curative treatment for relapsed or refractory lymphoma, and population-level patterns of HCT utilization among people with HIV are poorly characterized.

The purpose of this study is to quantify HCT utilization in people with HIV-lymphoma and examine the associations between sociodemographic factors and clinical characteristics of HCT utilization among people with HIV-lymphoma.

We used a linkage between the Center for International Blood and Marrow Transplant Research registry, California Cancer Registry, and the California Patient Discharge Database and included adults (18-79) diagnosed with first primary lymphoma in 1991-2016 following an HIV diagnosis. Cumulative incidence of HCT use for lymphoma, accounting for the competing risk of death, was estimated overall and by combination antiretroviral therapy (ART) eras. Adjusted cox proportional hazards models evaluated sociodemographic and clinical factors associated with HCT use.

Among 6,248 patients with HIV-lymphoma, the cumulative incidence of HCT use at 60 months was 4.8%. The cumulative incidence increased from 1.9% (95% confidence interval (CI): 1.0-3.5) in the pre-combination ART era (1991-1996), to 4.7% (CI: 3.5-6.1) in 1997-2005, and 7.2% (CI: 5.6-9.0) in 2006-2016 (p < 0.0001). Factors associated with lower HCT use included older age (Hazard Ratio [HR]=0.98, CI: 0.96-0.99), low socioeconomic status (HR=0.38, CI: 0.25-0.59), single/unmarried (HR=0.5, CI: 0.34-0.73), and public insurance (HR=0.64, CI: 0.44-0.93).

In this large, diverse population of people with HIV, HCT utilization increased after combination ART introduction, but remains low, with significant sociodemographic and clinical disparities that may limit access to current and future HCT therapies.