Growth failure and growth-hormone deficiency after treatment for acute lymphoblastic leukaemia

In a study of 77 children who had been treated for acute lymphoblastic leukaemia (ALL) with an LSA2L2 (Memorial Sloan-Kettering) chemotherapy protocol plus radiotherapy (24 Gy) as cranial prophylaxis, growth was examined 3.0-9.5 years after diagnosis. The children's growth slowed and they crossed height percentiles towards the end of or after treatment. The Z-score, which reflects the deviation of height measurements from the population mean, was used to assess height change. The mean Z-score was 0.16 at diagnosis, -0.30 2 years later, -0.71 4 years later, and -1.37 6 years later. Height for age had fallen by more than 1 standard deviation of the population mean in 32% of survivors 4 years after diagnosis and in 71% 6 years after diagnosis. Younger children and those tall for age at diagnosis were more severely affected. Growth-hormone (GH) response to standard provocation tests was measured in 46 patients; 30 had partial or complete GH deficiency. Mean pulsatile GH secretion was low in the 34 patients tested. Cranial irradiation is probably the most important causative factor in the development of GH deficiency in survivors of ALL.