P494: MYELOID LEUKEMIA IN PATIENTS WITH INFLAMMATORY BOWEL DISEASES: A RETROSPECTIVE COHORT STUDY

Abstract

Background: Inflammatory bowel diseases include ulcerative colitis and Crohn’s disease and affect around 3.1 million adults in the United States (US). The data on the risk of myeloid leukemia among patients with IBD are limited and there has been only a couple of studies that evaluated the incidence of myeloid leukemia in this patient population. Aims: This study aimed to estimate the prevalence of myeloid leukemia in patients with IBD. Secondary outcomes included mortality, length of stay, all-cause 30-day non-elective readmission rate, and total cost of hospitalization. Methods: This is a retrospective cohort study for patients with IBD in the US. We queried the Nationwide Readmission Databases 2016-2018 using ICD-10-CM codes to identify all adult patients admitted for IBD. Patients with a comorbid diagnosis of myeloid leukemia including acute myeloid leukemia (AML), chronic myeloid leukemia (CML), Myeloid sarcoma, and Unspecified Myeloid leukemia were identified. Figure 1 summarizes the case selection process. Median and IQR were used to describe Continuous variables, and proportions were used with categorical variables. Comparison between groups was performed by Mann Whitney test for continuous variables and Chi-Square test for Categorical variables. Multivariate regression analysis was performed to study the impact of comorbid myeloid leukemia on inpatient mortality and non-elective readmissions. Statistical analyses were performed using SPSS Version 25 (IBM Corporation, Armonk, NY, USA). Results: We extracted 365,152 index hospitalization records for IBD, 1052 (0.3%) had myeloid leukemia. Six hundred sixteen patients had acute myeloid leukemia (AML), 341 patients had chronic myeloid leukemia, 10 patients had myeloid sarcoma and 104 had unspecified myeloid leukemia. IBD patients with myeloid leukemia were older (64; Interquartile Range (IQR): 52-73 vs. 56; IQR: 38-70, P <0.001), more common to be males (50.8% vs. 49.2%, P <0.001) compared to IBD patients without myeloid leukemia. Having myeloid leukemia was associated with increased length of stays in days (7; Interquartile Range (IQR): 3-23 vs. 3; IQR: 2-6, P <0.001), increased median total charges ($74,413; IQR: $31,700 - $259,676 vs. $32,586; IQR: $17,827 - $62,260, P <0.001). On multivariate analysis; having myeloid leukemia was associated with increased mortality (Odds ratio (OR): 6.544; 95% confidence interval (CI): 5.318-8.052, P <0.001) and higher odds of all-cause 30-day non-elective readmission (OR: 1.4; 95% CI: 1.155-1.697, P= 0.001). Image:Summary/Conclusion: In our nationwide cohort of IBD patients, 0.3% had myeloid leukemia. Given the associated mortality and morbidity, we recommend considering a hematological consult for IBD patients with leukocytosis or leukopenia for further evaluation and appropriate management. More research studies are needed to investigate the pathogenesis of myeloid leukemia in IBD patients.