Time to Diagnosis and Treatment in an Underserved, Predominantly Hispanic Population of Adults in East Los Angeles- a Retrospective Study of Acute T- Lymphoblastic Leukemia/Lymphoma (T-ALL/LBL) Patients

Introduction

Acute T-lymphoblastic leukemia/lymphoma (T-ALL/LBL) comprises approximately 25% of adult ALL cases, while early T cell precursor ALL/LBL (ETP-ALL/LBL) is a small subset of T-ALL/LBL comprised of only early T cell precursors with a specific immunophenotype. Due in part to its rarity, limited data exists on underserved T-ALL patients specifically. Underserved patients face unique barriers in accessing healthcare and studies have found that these patients are at risk of delayed presentation for both acute and chronic conditions. Our study investigates duration from symptom onset to diagnosis and treatment in a predominantly underserved population of adults treated in East Los Angeles.

Methods

A retrospective chart review was performed of all patients with a confirmed pathologic diagnosis of T-ALL/LBL at two hospitals serving the population of East Los Angeles: Los Angeles County +USC Medical Center and Norris Comprehensive Cancer Center. We identified thirty-one patients diagnosed with T-ALL/LBL between January 1^st, 2011 and January 1^st, 2020. Demographic, clinical, and pathologic data were abstracted from medical records. Two patients were excluded from the analysis of extramedullary and mediastinal disease as this information was missing in their medical records. The primary aim of the study was to determine time from symptom onset to diagnosis and treatment. SAS software was used to conduct Kaplan-Meier analysis, in which six patients with unknown follow-up status are censored.

Results

In this study, 26 out of 31 patients (84%) had a non-ETP-ALL phenotype (T-ALL/LBL), while the remaining 5 (16%) were classified as ETP-ALL. The majority of the patients in this cohort were male (19/31; 61%) and Hispanic (17/31; 55%). The median age at diagnosis was 32 years (13-66). The median duration from symptom onset to diagnosis was 19 (2-192) days. The median duration from symptom onset to treatment was 29 days (3-240). The median duration from time of diagnosis to initiation of treatment was 6 days (1-48). The median white blood cell count at presentation was 8.1 per microliters (1.8 to 526.0 × 10^9/L). The median peripheral blood blasts at presentation was 35% (0%-91%). The median bone marrow blast percentage at diagnosis was 68%(0%-97%). Extramedullary disease at diagnosis was present in 76% (22/29), with the majority (59%; 17/29) presenting with bulky mediastinal disease. CNS disease was present in one patient (3%) at the time of diagnosis. USC-ALL was the most common induction regimen, received by 68% (21/31); followed by Hyper-CVAD, received by 23% (7/31). Two patients (6%) received alternative regimens and one patient (3%) did not undergo chemotherapy. Hematopoietic stem cell transplantation was performed in 48% (15/31). Currently, 55% (17/31) of patients are known to be alive, 26% (8/31) are deceased, and 19% (6/31) had unknown outcome, as they were lost to follow-up. One-year overall survival (OS) was 76% in T-ALL/LBL and 75% in ETP ALL/LBL patients, while both 3-year and 6-year OS were 65% and 75%, respectively.

Conclusions

Our study reveals that a predominantly underserved cohort of patients was diagnosed and treated within comparable timeframes to the general population reported in the existing literature. One study of mixed hematologic malignancies found a median interval from onset of symptoms to presentation of 30 days, whereas our patients presented within a median of 19 days after symptom onset. The same study showed a median of five days from time of diagnosis to initiation of treatment, as compared to a median of six days in our cohort. Studies have reported worse outcomes and complications in patients who presented later in their disease process, so our data is reassuring in that this underserved population is establishing care and being treated promptly. This underserved patient population in East Los Angeles is unique, however; many underserved patients do not have access to a major comprehensive cancer center, such as the patients in this study, who received care at Norris Comprehensive Cancer Center. Underserved T-ALL/LBL patients are an understudied population, and more research needs to be undertaken to evaluate the impact of the timing of diagnosis and treatment on the outcomes in this vulnerable patient population.

No relevant conflicts of interest to declare.