Myeloid neoplasia in children treated for solid tumours.

Therapy-related myeloid neoplasia developed 14 to 189 months after diagnosis of the primary malignancy in 12 out of 3365 children treated for malignant solid tumours; 6 of the 12 were in their first complete remission. The 10-year cumulative incidence of myeloid neoplasia was 1.3% (95% Cl 0.5-3.6) for the 447 patients with Hodgkin's disease, 1.3% (0.4-4.3) for the 420 with non-Hodgkin lymphoma, and 1.2% (0.3-5.2) for the 440 with neuroblastoma. This complication appeared in 1 of 180 children with brain tumours and in none of the 1878 with other malignancies. Risk of therapy-related myeloid neoplasia in patients with Hodgkin's disease was associated with recurrence of the primary malignancy, a combination of radiotherapy and chemotherapy with alkylating agents, and age greater than or equal to 12 years at diagnosis of Hodgkin's disease. Of the 8 patients who underwent chromosomal analysis of neoplastic myeloid cells, 2 showed complete loss of chromosome 7 and 4 showed t(9;11) or t(8;21) with or without del(16)(q22). The 2 patients who had received an epipodophyllotoxin had an 11q23 abnormality. The risk of therapy-related myeloid neoplasia is low in children with malignant solid tumours.