SURG-11. COMPARATIVE RISK ANALYSIS OF DEVELOPMENT OF ANEMIA IN RADIOTHERAPY-TREATED VS. NON-TREATED MULTIPLE SCLEROSIS PATIENTS: A MULTICENTER RETROSPECTIVE COHORT STUDY

Abstract INTRODUCTION The use of RT in patients who are diagnosed with multiple sclerosis (MS) is controversial due to adverse effects such as inflammation. Simultaneously, the relationship between oncologic RT and worsening anemia is well established. However, there is not a clear understanding of the risk associated with undergoing RT due to their oncologic diagnosis in MS patients for developing anemia. OBJECTIVE This study aims to analyze the risk of developing anemia for patients with MS who have been treated with RT versus who have not. METHODS This retrospective study consists of analysis of the data acquired from TriNetX, a database that houses clinical data from 92 healthcare organizations. Cohort 1 included MS patients with history of RT, while cohort 2 included MS patients without any history of RT. The cohorts were propensity score matched for demographics such as age, sex, race, and ethnicity. All neoplasms were also matched to eliminate cancer as a confounding variable. The analysis included outcomes of interest, ICD-10 code D64 (Other anemia), up to 6 months after the first occurrence of the index event. RESULTS 4,844 patients were identified for each cohort post-propensity score matching. The mean age was 65.4 and 67.3 years old, and most patients were white at 76.3% and 77.0% for the MS with RT and without RT cohorts, respectively. Cohort 1 had 628 patients who developed anemia, while cohort 2 only had 511 patients. The odds ratio was 1.263 with 95% confidence interval of 1.116 to 1.430 showing the statistically significant difference between the cohorts. CONCLUSION This study demonstrates that there is a significant increase in the likelihood of developing broadly categorized anemia for multiple sclerosis patients with or without radiation therapy. Further study is warranted to understand other potential factors leading to an increased risk of developing anemia in the irradiated cohort.