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Chromosome abnormalities, particularly monosomy 7, are present in 30% of chronic myelomonocytic leukemia (CMML) cases, indicating a poorer prognosis and younger patient age. No specific CMML anomaly was identified.
Area of Science:
- Hematology
- Cytogenetics
- Oncology
Background:
- Chronic myelomonocytic leukemia (CMML) is a heterogeneous myeloid malignancy.
- Karyotypic abnormalities play a role in leukemia prognosis.
- Understanding CMML cytogenetics is crucial for patient management.
Purpose of the Study:
- To investigate the spectrum and significance of chromosomal abnormalities in CMML.
- To correlate cytogenetic findings with clinical parameters and prognosis in CMML patients.
Main Methods:
- Retrospective multicenter study.
- Analysis of 120 CMML cases diagnosed by French-American-British (FAB) criteria.
- Karyotypic analysis of bone marrow chromosomes at diagnosis.
Main Results:
- Clonal chromosome abnormalities were found in 30% of CMML patients.
- Monosomy 7 was the most frequent abnormality, associated with younger age and poor prognosis.
- Other common anomalies included trisomy 8, iso(17q), and 12p anomaly; no anomaly was specific to CMML.
- Isochromosome 17q was observed only in the blastic phase; secondary leukemias were noted.
- Paraproteinemia occurred in 12% of patients without correlation to karyotypic anomalies.
Conclusions:
- Cytogenetic abnormalities in CMML are frequent and associated with clinical features and prognosis.
- Monosomy 7 is a significant adverse prognostic factor in CMML.
- Further research is needed to define specific cytogenetic markers for CMML subtypes.
Abstract:
In a retrospective multicenter study by the Groupe Français de Cytogénétique Hématologique, chromosome investigation was undertaken in 120 cases of chronic myelomonocytic leukemia, which was diagnosed in accordance with the French-American-British (FAB) criteria. Chromosome abnormalities of the clonal type were present at diagnosis in 30% of the patients. Median age of these patients was lower than for these without karyotypic abnormalities, and prognosis was less favorable. The most frequently encountered characteristic chromosome change was monosomy 7; chronic myelomonocytic leukemia (CMLL) with monosomy 7 occurs in younger age groups and has a very poor prognosis. Next in frequency were trisomy 8, iso(17q), and a 12p anomaly. The latter may have to be classified among the so-called primary characteristic chromosome changes in leukemia. All chromosome changes were of the type usually found in myeloid proliferation, and no anomaly specific for CMML was discovered. Isochromosome 17q was found only during blastic phase. Several of the CMML cases with chromosome anomalies were secondary leukemias, and among these was one case with a homogeneously staining region (HSR), which is rarely reported in leukemia. A paraproteinemia was found in 12% of the patients. No correlation of its occurrence with presence or type of karyotypic anomaly could be found.