Survival Disparities Among Overweight and Obese Adolescent and Young Adult Patients with Acute Lymphoblastic Leukemia in a Large Integrated Healthcare System

• Published in: Blood 2024-11, Vol.144, p.5125-5125
• Main Authors: Newman, Matthew, Zhuang, Zimin, Chao, Chun R., Cooper, Robert
• Format: Article
• Language: English
• ISSN: 0006-4971
• DOI: 10.1182/blood-2024-194050

Introduction: Acute leukemias are highly prevalent diagnoses among adolescent and young adult (AYA) patients and are a leading cause of mortality in this age group despite promising therapeutic advancements. Obesity, often measured in surrogate by body mass index (BMI), is an increasingly common condition in the United States, including in AYAs, and is associated with inferior survival outcomes across many cancer types. Recent work has shown that AYAs undergoing treatment for B- or T-acute lymphoblastic leukemia (B-ALL, T-ALL) are adversely impacted by obesity as well, both in terms of treatment-related toxicities and overall survival (OS). Thus far, this relationship has been examined in the context of clinical trials with limited ethnic inclusion. Data detailing outcomes for racially and socioeconomically diverse AYA patients treated in the community setting are sparse. Herein, we describe the impact of obesity on survival outcomes in a diverse set of AYAs being treated for ALL within a large integrated healthcare system. Methods: Patient data were derived from the Kaiser Permanente Southern California (KPSC) membership, where patients are diagnosed, treated, and followed within a single integrated healthcare system. KPSC members have relatively equal access to care. 140 AYA patients aged 15-39 diagnosed with B- or T-ALL were identified via ICD-O-3 histology codes from 2010-2018. Descriptors of age, race/ethnicity, census-level median household income, and BMI within one year prior to diagnosis were abstracted from KPSC's electronic health records. BMI was categorized by World Health Organization (WHO) definitions. Comorbidities were captured using a modified Elixhauser comorbidity index (ECI) excluding obesity and cancer-related conditions. The Kaplan-Meier method was used to construct survival curves for OS, alongside Log-rank testing of survival equivalence. Bivariate and multivariable Cox proportional hazards (PH) modeling was employed to determine hazard ratios (HRs) and confidence intervals (CIs). Results: The 140 included patients were ethnically diverse, with nearly 80% identifying with a background other than non-Hispanic white. Half (51%) were from lower socioeconomic brackets as measured by census-level income. One third (31%) were a normal weight (BMI 18.5-24.9), with the other two thirds (59%) presenting as overweight (BMI 25-29.9), obese (BMI 30-39.9), or severely obese (BMI ≥ 40) at the time of diagnosis. Most were diagnosed with B-ALL (76