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AML-associated cytogenetic abnormalities (inv (16), del (16), t(8;21)) in patients with myelodysplastic syndromes
E Estey1, J M Trujillo, A Cork
1Department of Hematology, University of Texas M.D. Anderson Cancer Center, Houston 77030.
Abstract:
Evidence suggests that prognosis in patients with myelodysplastic syndromes (MDS) or acute myelogenous leukemia (AML) depends more on karyotype than on formal classification as either MDS or AML according to the French-American-British (FAB) system. We provide further evidence of overlap between these two entities, reporting 4 patients who presented with either inv(16) (p13q22), del(16) (q22), or t(8;21) despite an FAB diagnosis of MDS rather than the diagnosis of AML with which these abnormalities are generally associated. In 3 patients, disease was relatively long-standing (3-10 months) prior to diagnosis, suggesting that the association between MDS and these cytogenetic abnormalities may not merely reflect a transient phenomenon. Two patients with inv(16) and the MDS subtype refractory anemia with excess blasts in transformation (RAEB-t) received AML-type chemotherapy as did a patient with t(8;21) and RAEB-t. All entered CR paralleling the high CR rate seen in patients with AML and these abnormalities. Our data support the concept that MDS and AML may be different manifestations of the same disease.
Insights
Myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) may share underlying biology, as evidenced by specific genetic abnormalities. Patients with MDS and AML-associated karyotypes responded well to AML-type chemotherapy, suggesting a unified disease spectrum.
Area of Science:
- Hematology
- Oncology
- Genetics
Background:
- Prognosis in myelodysplastic syndromes (MDS) and acute myelogenous leukemia (AML) appears strongly linked to specific chromosomal abnormalities (karyotype).
- The French-American-British (FAB) classification system may not fully capture the biological relationship between MDS and AML.
- Certain cytogenetic abnormalities, typically associated with AML, are sometimes observed in MDS patients.
Observation:
- Four patients diagnosed with MDS under the FAB system presented with cytogenetic abnormalities usually seen in AML: inv(16), del(16), or t(8;21).
- In three cases, the disease was present for several months before diagnosis, indicating these cytogenetic findings in MDS are not transient.
- Two patients with inv(16) and one with t(8;21), all classified as MDS subtype refractory anemia with excess blasts in transformation (RAEB-t), received standard AML chemotherapy.
Findings:
- All patients treated with AML-type chemotherapy achieved complete remission (CR).
- This high CR rate mirrors that observed in AML patients with similar cytogenetic abnormalities.
- The presence of AML-associated karyotypes in MDS patients and their response to AML-directed therapy suggests a shared underlying pathology.
Implications:
- MDS and AML might represent different clinical manifestations of a single disease continuum.
- Karyotype may be a more critical prognostic and therapeutic indicator than the FAB classification alone.
- These findings could influence future diagnostic criteria and treatment strategies for myeloid malignancies.