Characteristics and long‐term outcome in a large series of chronic myelomonocytic leukaemia patients including 104 formerly referred to as oligomonocytic

Abstract

SummaryRecently modified diagnostic criteria for chronic myelomonocytic leukaemia (CMML) have lowered the cut‐off for absolute monocytosis. In the largest series to date, we have analysed 313 CMML patients, including 104 with oligomonocytic (OM)‐CMML. Five‐year survival was longer for OM‐CMML than for other patients (p < 0.001). Multivariate analysis identified OM‐CMML as a favourable prognostic factor (HR 0.58; p = 0.002). The 5‐year cumulative incidence of progression to classical CMML was 47%. Older age and transfusion dependence were adverse prognostic factors for OM‐CMML. Our results support the inclusion of OM‐CMML in the CMML category as a subtype with superior outcomes.

Chronic myelomonocytic leukemia with ring sideroblasts/SF3B1 mutation presents with low monocyte count and resembles myelodysplastic syndromes with-RS/SF3B1 mutation in terms of phenotype and prognosis

“…Because SRSF2 has not been detected in the healthy elderly population (unlike TET2 and ASXL1 ) and although this mutation is not specific of this disease, it is useful as a clonal marker in the differential diagnosis of other causes of monocytosis ( 25 ). Moreover, co-occurrence of mutations in SRSF2 and TET2 , and the presence of multiple TET2 mutations, are considered hallmarks of CMML ( 21 , 22 , 26 ). In MDS, SF3B1 mutations are present in 80% of patients with MDS with RS (90% of MDS-RS-UD and in 70% MDS-RS-MD based on the 2017 WHO classification) 10 .…”

Should oligomonocytic CMML be classified as an independent disease entity?

“…In their paper, the authors 5 presented a large retrospective study of CMML (including 16% O‐CMML cases) with a 10‐year median follow‐up and provided their argument for viewing O‐CMML as an independent entity within CMML.…”

“…What about patient care? O‐CMML patients are mostly low risk based on major risk stratification models and are often monitored without active anti‐neoplastic treatment 5,6 . Therefore, there are little data available to answer whether O‐CMML patients should receive targeted therapy or which medication is more beneficial for patient survival.…”

“…Novel types of targeted therapies with superior safety profiles are clearly needed. Additionally, the rarity of O‐CMML (estimated at 0.64 per million annually in the United States 5,8 ) adds to the difficulties of carrying out clinical trials focused on such disease subtype. Perhaps creative trials that combine O‐CMML and myeloid disease precursor conditions with high likelihood of progression, such as high‐risk clonal haematopoiesis of indeterminate potential (CHIP) and high‐risk clonal cytopenia of undetermined significance (CCUS) defined by clonal haematopoiesis risk score (CHRS), 1,9 are needed for testing long‐term early intervention treatment options.…”