Abstract 4411: Clinicopathologic determinants of survival in enteropathy-associated T-cell lymphoma (EATL): analysis of a pooled database
Authors: Haddad Philip A. , Malireddy Sai 
Published: April 2023

Abstract
Background: EATL is a rare and rapidly progressive extranodal T-cell lymphoma which arises from the intestinal intraepithelial T lymphocytes. It often occurs in the context of untreated or long-standing Celiac disease (CD) or the development of refractory sprue. EATL tends to be less responsive to conventional chemotherapy, often with poor clinical outcomes. We conducted this analysis to explore the clinicopathologic determinants of survival in this rare extranodal T-cell entity.
Methods: To study the demographic characteristics, molecular and immunohistochemical signatures, therapeutic interventions, survival, and prognostic factors, we compiled a pooled database of 220 cases. Kaplan-Meier survival curves were constructed. Cox proportional-hazards model and Log-rank tests were used to assess the influence of demographic and clinicopathologic factors on overall survival (OS).
Results: A total of 220 patients with confirmed EATL were identified. The median age was 60, with a peak incidence between 64 and 75. There was a slight female predominance with F:M ratio of 1.1. The jejunum was the most involved site (47%). The median OS of the whole group was 10 months. The most common presentations were abdominal pain, followed by perforation, diarrhea, obstruction, and gastrointestinal bleeding. The majority presented at stage I&II (53%). The median duration of symptoms before diagnosis was 2 months. Younger patients (p=0.02) and HLH (p=0.006) had worse OS. The time interval between diagnosing CD and EATL impacted OS, with &lt;1 yr and &gt;20yrs having worse outcomes (p=0.04). Combination chemotherapy and stem cell transplant (SCT) were statistically superior to no treatment, with a median OS of 11, 22, and 0.75 months respectively (p=0.002). Further analysis revealed that surgical resection imparted a survival advantage in combination with chemotherapy and SCT. When surgical resection was incorporated into the analysis, median OS amounted to 0.75, 9, 16, 8, 69 months for surgery alone, chemotherapy, surgery+chemotherapy, SCT, and surgery+SCT, respectively (p=0.003). Combinations that used anthracyclines (p=0.02) and etoposide (p=0.05) had better OS. The quality of response to treatment also seemed to impact the outcome (p=0.0001) with median OS of 9, 9, and 69 months for &lt;PR, PR, and CR, respectively. OS was not impacted by stage, constitutional symptoms, presentation with obstruction or perforation, or CD30+. While male sex, colon and visceral involvement, and null TCR type seemed to impact OS negatively, they did not reach statistical significance.
Conclusions: This study presents updated clinicopathologic data from a pooled cohort of patients with EATL. It identifies age, CD duration, HLH, treatment modalities, and quality of response as major determinants of OS in this rare disease.
Citation Format: Philip A. Haddad, Sai Malireddy. Clinicopathologic determinants of survival in enteropathy-associated T-cell lymphoma (EATL): analysis of a pooled database. [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 4411.