Juvenile myelomonocytic leukemia: A national analysis of demographic features.

Abstract

e19086 Background: Juvenile Myelomonocytic Leukemia (JMML) is a rare hematological cancer originating in the bone marrow. It is a type of myelodysplastic syndrome (MDS) characterized by abnormal production of myeloid progenitor cells and monocytes. This malignancy is predominant in males, has a median age of diagnosis of 2 years, and carries a poor prognosis. It only accounts for 1% of all pediatric leukemias but constitutes 20-40% of pediatric MDS cases, making it the most common MDS subtype in children. Hematopoietic stem cell transplant (HSCT) is the only known cure for JMML, but its efficacy is just 50%. Without treatment, patients survive for a median of 10-12 months. Given the rarity of JMML, an analysis of demographic trends could offer valuable epidemiological insight. The National Cancer Database (NCDB) database was used to examine major demographic features of JMML. Methods: A retrospective analysis of all patients diagnosed with JMML between 2004 – 2020 in the NCDB (N = 242) was performed. Demographic factors including sex, race, Hispanic ethnicity, household income status, insurance status, urban/rural status, and Charlson-Deyo score were examined by descriptive statistics. Treatment statistics were also analyzed. Linear regression was used to determine incidence trends. Results: A total of 242 patients were identified with a histologically-confirmed diagnosis of JMML. Most patients were male (67.4%). The average age of diagnosis was 2 years (SD = 3.69, range = 0-33). The average incidence was 14.2 patients diagnosed per year (SD = 3.7, range = 9 – 21, R2 = 0.131). 93.8% had a Charlson-Deyo comorbidity score of 0. The majority of patients were White (74.4%), followed by Black (11.6%). 16.1% of patients were of Hispanic ethnicity. The distribution of median household income was 27.4% in the top quartile, 26.9% in the second, 26.9% in the third, and 18.7% in the fourth. Most patients were either privately insured (49.6%) or insured by Medicaid (42.6%). 75.5% of patients lived in a county with 250,000 people or more. Most patients received treatment (84.6%), while some only received active surveillance (8.7%) or no treatment (6.7%). Conclusions: This is the first NCDB analysis describing the demographic trends of JMML. Patients were twice as likely to be male than female. They were most likely to be White, with an average age of 2 years. This data reflects the expected age group and sex/race predominance described in the literature. The proportion of Hispanic JMML patients was comparable to Hispanics in the general US population. JMML appeared to be nearly evenly distributed among the top three household income quartiles. The lowest income quartile and rural inhabitants were least affected by this disease, which may indicate underdiagnosis in these populations. Further studies are needed to better define the relevance of these individual factors in the diagnosis, treatment, and survival of patients with JMML.