Contributions
Abstract: PB1706
Type: Publication Only
Background
The t(8;21) rearrangement is closely associated with AML-M2 and is often co-detected with deletion 9q, and loss of the sex chromosomes. This abnormality is associated with a favourable prognosis. On the other hand, its coexistence with trisomy 4 is uncommon and the clinical significance is unclear.
Aims
To highlight the disease course of two patients with AML harbouring a co-existing t(8;21)(q22q22) and trisomy 4 abnormality.
Methods
Bone marrow cells were cultured at 37OC for 24 and 48hrs and cells from both samples were harvested as per standard protocol. Cytogenetic analysis was carried out on G-banded metaphase cells.
Results
Both patients had trisomy 4 in addition to a t(8;21) rearrangement in the first patient and a t(8;10;21)(q22;q24;q22) rearrangement in the second patient. c-KIT exon 17 mutation was detected in both patients.
The first patient achieved complete remission after 35 days of induction. However, the patient relapsed after 5 months of myeloablative haemotopoietic stem cell transplant (HSCT). A more complex 47,XX,t(3;10)(p21;q24),+4,t(8;21)(q22;q22) karyotype was obtained. Disease progression was evidenced by the additional abnormality. The patient achieved complete remission in the marrow after a complicated course of chemotherapy.
After nine months of HSCT, the second patient developed granulocytic sarcoma in the sternum. He achieved remission and the marrow showed a normal karyotype and all cells were of donor origin after one year of treatment.
Conclusion
To our knowledge, there are only 4 reported cases of AML with co-existing t(8;21) and trisomy 4 in the Asian population. No detailed cytogenetic investigation and treatment regimens were reported by these authors. Our first patient had a slow response to treatment and a rapid relapse with disease progression despite early ablative HSCT at first remission. The second patient developed granulocytic sarcoma after the HSCT. From the observation of these two patients, the presence of the trisomy 4 may define a unique subtype of AML with t(8;21)(q22;q22). Such patients should be monitored closely for risk of relapse.
c-KIT mutation has been shown to confer drug resistance. Treatment with novel therapy inhibiting KIT tyrosine kinase activity may be of potential value.
Session topic: 3. Acute myeloid leukemia - Biology & Translational Research
Keyword(s): AML, AML1-ETO, C-kit
Abstract: PB1706
Type: Publication Only
Background
The t(8;21) rearrangement is closely associated with AML-M2 and is often co-detected with deletion 9q, and loss of the sex chromosomes. This abnormality is associated with a favourable prognosis. On the other hand, its coexistence with trisomy 4 is uncommon and the clinical significance is unclear.
Aims
To highlight the disease course of two patients with AML harbouring a co-existing t(8;21)(q22q22) and trisomy 4 abnormality.
Methods
Bone marrow cells were cultured at 37OC for 24 and 48hrs and cells from both samples were harvested as per standard protocol. Cytogenetic analysis was carried out on G-banded metaphase cells.
Results
Both patients had trisomy 4 in addition to a t(8;21) rearrangement in the first patient and a t(8;10;21)(q22;q24;q22) rearrangement in the second patient. c-KIT exon 17 mutation was detected in both patients.
The first patient achieved complete remission after 35 days of induction. However, the patient relapsed after 5 months of myeloablative haemotopoietic stem cell transplant (HSCT). A more complex 47,XX,t(3;10)(p21;q24),+4,t(8;21)(q22;q22) karyotype was obtained. Disease progression was evidenced by the additional abnormality. The patient achieved complete remission in the marrow after a complicated course of chemotherapy.
After nine months of HSCT, the second patient developed granulocytic sarcoma in the sternum. He achieved remission and the marrow showed a normal karyotype and all cells were of donor origin after one year of treatment.
Conclusion
To our knowledge, there are only 4 reported cases of AML with co-existing t(8;21) and trisomy 4 in the Asian population. No detailed cytogenetic investigation and treatment regimens were reported by these authors. Our first patient had a slow response to treatment and a rapid relapse with disease progression despite early ablative HSCT at first remission. The second patient developed granulocytic sarcoma after the HSCT. From the observation of these two patients, the presence of the trisomy 4 may define a unique subtype of AML with t(8;21)(q22;q22). Such patients should be monitored closely for risk of relapse.
c-KIT mutation has been shown to confer drug resistance. Treatment with novel therapy inhibiting KIT tyrosine kinase activity may be of potential value.
Session topic: 3. Acute myeloid leukemia - Biology & Translational Research
Keyword(s): AML, AML1-ETO, C-kit