Bravo, Guillermo Montalban

Abstract Recent updates to monocyte count thresholds recognize oligomonocytic chronic myelomonocytic leukemia (OM-CMML) as an early form of CMML. However, the clinical validity of these changes remains uncertain without incorporating biological and genomic factors. In this study, we analyzed a cohort of 911 patients (249 with OM-CMML, 359 with overt CMML, and 303 with myelodysplastic syndromes) using unsupervised clustering to evaluate the role of genomic determinants in refining CMML diagnosis. Our findings show that CMML molecular signatures (biallelic TET2 mutations or SRSF2-TET2 comutations) are linked to a distinct transcriptome, monocytic bias, classical monocytosis, and a higher risk of progression to overt CMML in OM-CMML cases. We developed a weighted genomic model and diagnostic workflow showing that combining genomic signatures with bone marrow monocyte frequencies in OM-CMML more accurately predicts progression to overt CMML. These findings support integrating genomic determinants and our clinic-ready diagnostic workflow into the CMML diagnostic framework to improve accuracy. Significance: Through comprehensive clinical and genomic profiling of a large patient cohort, alongside immunophenotypic and transcriptional cellular analyses, this study provides evidence that incorporating genomic determinants into the diagnostic criteria for OM-CMML improves diagnostic accuracy and refines the identification of early-stage CMML, thereby preventing misclassification.

ABSTRACT Background Chronic myelomonocytic leukemia (CMML) is largely a disease of individuals older than 50 years; its occurrence in patients aged 50 years and younger is rare. The authors sought to characterize the clinicopathologic features and genetic profile of young‐onset (age 50 years and younger) CMML (y‐CMML) compared with older onset (older than 50 years) CMML (o‐CMML). Methods The authors conducted a multi‐institutional study of 32 patients with y‐CMML and 119 patients with o‐CMML, analyzing clinical, morphologic, cytogenetic, and molecular data. Results Patients who had y‐CMML frequently presented with splenomegaly (59% vs. 11%; p < .001) and hepatomegaly (25% vs. 2%; p < .001) compared with those who had o‐CMML. Although the overall incidence of cytogenetic abnormalities was similar, patients who had y‐CMML exhibited distinct mutational patterns. PTPN11 mutations were significantly more common in y‐CMML (13% vs. 3%; p = .034) than in o‐CMML, whereas TET2 (6% vs. 57%; p < .001) and SRSF2 (16% vs. 46%; p = .002) mutations were significantly less frequent. In addition, multi‐hit TET2 (6% vs. 34%; p = .002) and TET2‐SRSF2 (3% vs. 29%; p = .003) co‐mutations were rare in y‐CMML. However, the molecular differences did not affect the CMML‐specific risk‐stratification categories because the clinical outcomes, including overall survival and leukemia‐free survival, did not differ between the two groups. Conclusions CMML in patients aged 50 years and younger is rare and presents with unique clinical and mutational features, suggesting a distinct pathogenesis.

AbstractThe progress with intensive chemotherapy and supportive care measures has improved survival in patients with newly diagnosed acute myeloid leukemia (AML). Given the recent development of effective low intensity therapies, an optimal decision on the therapy intensity may improve survival through the avoidance of early mortality. We reviewed the outcome of 3728 patients with newly diagnosed AML who received intensive chemotherapy between August 1980 and May 2020. Intensive chemotherapy was defined as a cumulative cytarabine dose ≥ 700 mg/m2 during induction therapy. We divided the whole cohort into a training and validation group at a 3:1 ratio. The population was divided into a training (2790 patients) and a validation cohort (938 patients). The median age was 55 years (range, 15‐99). Among them, 442 patients (12%) had core‐binding factor AML. Binary logistic regression identified older age, worse performance status, hyperbilirubinemia, elevated creatinine, hyperuricemia, cytogenetic abnormalities other than CBF and ‐Y, and pneumonia as adverse prognostic factors for an early 4‐week mortality. This risk classification for early mortality was verified in the validation cohort of patients. In the validation cohort of more recently treated patients from 2000 to 2017, the 4‐week mortality rates with intensive chemotherapy were 2%, 14%, and 50% in the low‐, high‐, and very high‐risk group, respectively. The mortality rates with low intensity therapies were 3%, 9%, and 20%, respectively. The risk classification guides treatment intensity by the assessment of age, frailty, organ dysfunction, cytogenetic abnormality, and infection to avoid early mortality.