Therapy-related myeloid neoplasms in children and adolescents

BACKGROUND: This retrospective study aimed to characterize and analyze the outcome of therapy-related myeloid neoplasms (t-MNs) in children and adolescents. METHODS: The medical records of 16 patients under 21 years of age at the time of t-MN diagnosis were reviewed. RESULTS: The median patient age was 11.5 years (range, 1.6–20.4 yr). Twelve patients had therapy-related acute myeloid leukemia, 3 patients had myelodysplastic syndrome, and 1 patient had chronic myelomonocytic leukemia. The median latency period was 29 months (range, 11–68 mo). Fourteen patients had cytogenetic aberrations, 8 of whom had an 11q23 abnormality. Of the 13 patients treated with curative intent, 12 patients received myeloid-type induction therapy that led to complete remission (CR) in 8 patients. Nine patients underwent allogeneic transplantation; 4 patients did not undergo transplantation due to chemotherapy-related toxic death (N=3) or parental refusal (N=1). The 5-year overall survival and event-free survival of the 13 patients treated with a curative intent were 46.2% and 30.8%, respectively. For the 9 patients who underwent allogeneic transplantation, the 5-year event-free survival was 66.7%. CONCLUSION: A significant proportion of young patients with t-MNs can experience long-term survival, and allogeneic transplantation plays a key role for attaining cure in these patients.

Dismal outcome of therapy-related myeloid neoplasm associated with complex aberrant karyotypes and monosomal karyotype: a case report

Introduction: Individuals who are exposed to cytotoxic agents are at risk of developing therapyrelated myeloid neoplasms (t-MN). Cytogenetic findings of a neoplasm play an important role in stratifying patients into different risk groups and thus predict the response to treatment and overall survival. Case report: A 59-year-old man was diagnosed with acute promyelocytic leukaemia. Following this, he underwent all-trans retinoic acid (ATRA) based chemotherapy and achieved remission. Four years later, the disease relapsed and he was given idarubicin, mitoxantrone and ATRA followed by maintenance chemotherapy (ATRA, mercaptopurine and methotrexate). He achieved a second remission for the next 11 years. During a follow-up later, his full blood picture showed leucocytosis, anaemia and leucoerythroblastic picture. Bone marrow examination showed hypercellular marrow with trilineage dysplasia, 3% blasts but no abnormal promyelocyte. Fluorescence in-situ hybridisation (FISH) study of the PML/RARA gene was negative. Karyotyping result revealed complex abnormalities and monosomal karyotype (MK). A diagnosis of therapy-related myelodysplastic syndrome/myeloproliferative neoplasm with unfavourable karyotypes and MK was made. The disease progressed rapidly and transformed into therapy-related acute myeloid leukaemia in less than four months, complicated with severe pneumonia. Despite aggressive treatment with antibiotics and chemotherapy, the patient succumbed to the illness two weeks after the diagnosis. Discussion and Conclusion: Diagnosis of t-MN should be suspected in patients with a history of receiving cytotoxic agents. Karyotyping analysis is crucial for risk stratification as MK in addition to complex aberrant karyotypes predicts unfavourable outcome. Further studies are required to address the optimal management for patients with t-MN.