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Updated: Sep 12, 2026
Modeling Chemotherapy Resistant Leukemia In Vitro
Published on: February 9, 2016
Inferior Survival in Therapy-Related Chronic Myelomonocytic Leukemia: A Population-Based Analysis
Arjun Syal1, Douglas Tremblay2
1Department of Internal Medicine, Mount Sinai Morningside and West, Icahn School of Medicine at Mount Sinai, New York, USA.
Introduction:
The prognostic impact of therapy-related chronic myelomonocytic leukemia (t-CMML) compared with de novo CMML (dnCMML) remains uncertain, in part due to the absence of therapy-related designations in cancer registries.
Methods:
Using the Surveillance, Epidemiology, and End Results (SEER) database, we compared outcomes between dnCMML and t-CMML, operationally defined by antecedent chemotherapy and/or radiotherapy and diagnosis as a subsequent primary malignancy. Survival was evaluated by antecedent treatment exposure and within major antecedent malignancy groups. Additional operational definitions of t-CMML were evaluated to assess the robustness of findings.
Results:
Among 8,432 patients diagnosed with CMML between 2000 and 2022 after exclusion of antecedent myeloid malignancies, 594 (7.0%) met criteria for the primary definition of t-CMML. Median overall survival (OS) for the entire CMML cohort was 18 months, with shorter median OS observed for t-CMML compared with dnCMML (14 vs. 19 months). On multivariable Cox regression adjusted for age, sex, race, and era of diagnosis, t-CMML was associated with an increased risk of death (hazard ratio 1.20, 95% CI 1.09-1.32). Compared with dnCMML, inferior OS was observed among patients with recorded chemotherapy exposure but not among those treated with radiotherapy alone. Direct comparisons between chemotherapy-exposed and radiotherapy-only patients showed no significant difference in OS in the pooled adjusted analysis or within individual antecedent malignancy groups. Increasing definitional stringency was associated with stepwise worsening OS.
Conclusion:
Registry-defined t-CMML was associated with inferior survival compared with de novo disease. Although chemotherapy-exposed t-CMML was associated with poorer outcomes relative to dnCMML, OS did not differ significantly between chemotherapy-exposed and radiotherapy-only patients in direct pooled or malignancy-specific comparisons. Studies integrating detailed treatment histories with molecular and cytogenetic data are needed to clarify the biology and prognostic significance of t-CMML.