Patterns of venous thromboembolism risk, treatment, and outcomes among patients with cancer from uninsured and vulnerable populations.

Abstract

The epidemiology of cancer-associated thrombosis (CAT) among uninsured and vulnerable populations in the US is not well-characterized. We performed a retrospective cohort study for patients with newly diagnosed cancer from 2011 to 2020 at Harris Health System, which cares for uninsured residents in the Houston metropolitan area. Patient demographics, NCI comorbidity index, area of deprivation index (ADI), cancer histology, staging, and systemic therapy data were extracted. CAT included overall venous thromboembolism (VTE) or pulmonary embolism +/- lower extremity deep vein thrombosis (PE/LE-DVT) within 1 year of diagnosis. We used multivariable Fine-Gray models to assess the associations with CAT accounting for death as a competing risk. Among 15 342 patients, 74% were uninsured and 84% lived in socioeconomically disadvantaged neighborhoods. There were 16% Non-Hispanic White (NHW), 28% Non-Hispanic Black (NHB), 50% Hispanic (27% Mexican), and 6% Asian/Pacific Islanders (API). The 1-year CAT incidence rate was 14.6%. Overall VTE was lower for Hispanics versus NHW (SHR 0.87 [0.76-0.99]) and API versus NHW (SHR 0.58 [0.44-0.77]). PE/LE-DVT was higher for NHB versus NHW (SHR 1.18 [1.01-1.39]). CAT was also associated with chemotherapy-based regimens (+/- immunotherapy), age, obesity, cancer type/staging, VTE history, and recent hospitalization. NCI comorbidity and ADI scores were associated with mortality but not CAT. In a large cohort of underserved patients with cancer, we identified an elevated incidence of CAT with known and novel risk predictors. Hispanics had lower adjusted rates of CAT and mortality. Our findings highlight the need to investigate and incorporate vulnerable populations in clinical trials.