Prognosis of children with chronic myeloid leukemia: a retrospective analysis of 75 patients

Abstract

As the probability of survival of patients with chronic myelocytic leukemia (CML) gradually decreases over a period of 10 years, long-term follow-up is mandatory. Between 1977 and 1994, 68 children and adolescents between 1.0 and 18 years of age with CML in chronic phase and 7 presenting with blast crisis at diagnosis were reported to the study center in Münster. The Philadelphia-chromosome and/or BCR/ABL rearrangement could be detected in 66 children. The 4 Philadelphia-negative patients and 5 patients without karyotyping fulfilled the morphological criteria of CML. Clinical symptoms and hematological findings at presentations were similar to adult patients. Until 1985 chemotherapy consisted predominantly in busulfan (BU), later in hydroxyurea (HU) or a combination of both and since 1987 increasingly in HU plus interferon-alpha. 47 patients (6 in blast crisis) were allografted once or twice (n = 4) (27 HLA-identical, 16 unrelated, 4 haplo-identical) within 2.3-135 months (median 12 months) after diagnosis. 38 of 75 patients (3 in blast crisis at diagnosis) were alive after a median follow-up of 5.5 years. The probability of 12 years survival was 27%, SE 9% for patients in chronic phase. All deaths (n = 19) were leukemia-related in the 27 non-transplanted children. A comparison of survival for patients with or without bone-marrow transplantation (BMT) showed a significant difference in favour of the BMT-group (42%, SE 13% vs. 10%, SE 8%, p log-rank 0.003). The probability of survival increased to 62%, SE 10%, if patients transplanted later than 3 years after diagnosis were excluded. Only few patients (4/39 with information about the cause of death = 10%) died due to recurrent CML after BMT. Our data confirm the unfavourable outcome of CML in pediatric patients if treated with chemotherapy alone. With early BMT high cure rates can be achieved. If transplant-related mortality which in our patient group was 21% (8/39) can be reduced, even a higher cure rate appear realistic for the future.