[Clinical Characteristics and Prognostic Analysis of the Chronic Myelomonocytic Leukemia]

To analyze and explore the clinical characteristics and prognostic factors of chronic myelomonocytic leukemia (CMML), a rare hematological malignancy, thereby providing insights for basic research and clinical management in hematology.

Retrospective analysis was conducted on the clinical data of 64 newly diagnosed CMML patients from three hospitals between January 2018 and January 2025. Clinical features, treatment outcomes and prognosis were summarized. Kaplan-Meier survival analysis, Log-rank tests, and Cox proportional hazards regression models were employed to evaluate prognostic factors.

A total of 64 patients were included: 36 males (56.25%) and 28 females (43.75%). The median age at onset was 64 years (range, 28-87). According to the French-American-British (FAB) classification, 19 cases were MD-CMML and 45 were MP-CMML. Based on the World Health Organization (WHO) classification,14 cases were CMML-0, 19 CMML-1, and 31 CMML-2. Bone marrow morphology revealed dysplasia in 46 cases: 19 with single-lineage, 16 with bilineage, and 11 with trilineage involvement. Bone marrow biopsy showed active hyperplasia in 37 cases, decreased hyperplasia in 27, and concurrent myelofibrosis in 18. Cytogenetic analysis was performed in 56 patients, with abnormalities detected in 7 (12.5%). Molecular testing was performed in 45 patients, and gene mutations were identified in 20 (44.4%). The primary first-line treatment for the included patients with CMML was chemotherapy, 17 patients received only symptomatic and supportive care. Among 47 patients with evaluable treatment responses, 23 achieved complete remission, 15 achieved partial remission, 8 had stable disease, and 1 had progressive disease. As of May 1, 2025, 37 patients (57.8%) were alive, 24 (37.5%) had died, and 3 (4.69%) were lost to follow-up. The median overall survival (OS) was 23 months. Low hemoglobin levels, lactate dehydrogenase (LDH) ≥250 U/L, and a peripheral blast count (PBC) ≥5% were significantly associated with inferior OS (P<0.05). PBC≥5% was identified as an independent risk factor affecting OS in CMML patients.

CMML lacks distinctive clinical features and is often accompanied by pathological hematopoiesis and molecular biological abnormalities, with a poor prognosis. PBC≥5% is an independent risk factor for OS in patients with CMML.