Cytogenetic risk stratification of 417 patients with chronic myelomonocytic leukemia from a single institution

Approximately 30% of patients with chronic myelomonocytic leukemia (CMML) have karyotypic abnormalities and this low frequency has made using cytogenetic data for the prognostication of CMML patients challenging. Recently, a three-tiered cytogenetic risk stratification system for CMML patients has been proposed by a Spanish study group. Here we assessed the prognostic impact of cytogenetic abnormalities on overall survival (OS) and leukemia-free survival (LFS) in 417 CMML patients from our institution. Overall, the Spanish cytogenetic risk effectively stratified patients into different risk groups, with a median OS of 33 months in the low-, 24 months in intermediate- and 14 months in the high-risk groups. Within the proposed high risk group, however, marked differences in OS were observed. Patients with isolated trisomy 8 showed a median OS of 22 months, similar to the intermediate-risk group (P=0.132), but significantly better than other patients in the high-risk group (P=0.018). Furthermore, patients with more than three chromosomal abnormalities showed a significantly shorter OS compared with patients with three abnormalities (8 vs. 15 months, P=0.004), suggesting possible a separate risk category. If we simply moved trisomy 8 to the intermediate risk category, the modified cytogenetic grouping would provide a better separation of OS and LFS; and its prognostic impact was independent of other risk parameters. Our study results strongly advocate for the incorporation of cytogenetic information in the risk model for CMML. Am. J. Hematol. 89:813-818, 2014.