Factors that affect final height and change in height standard deviation scores in survivors of childhood cancer treated with growth hormone: a report from the childhood cancer survivor study.

Abstract

GH deficiency is a common late complication in survivors of pediatric malignancies, particularly those who are treated with radiation (RT) to the hypothalamic-pituitary region. Nonetheless, few reports have assessed final height outcomes in survivors treated with GH. In the present study, we investigated which patient and treatment variables correlate with final height and change in height sd score (SDS) in a large cohort of cancer survivors treated with GH. We previously identified 361 participants in the multicenter Childhood Cancer Survivor Study who were treated with GH. Final height data were available in 183 survivors (120 males). Diagnoses included: central nervous system tumors (n = 90), acute leukemia (n = 64), soft tissue sarcomas (n = 23), and miscellaneous (n = 6). The median age at diagnosis of the primary cancer was 4.6 yr, and the median age at start of GH treatment was 11.3 yr. Mean height SDS at start of GH therapy was -2.03 +/- 0.8, and the mean final height SDS was -1.48 +/- 0.10 (P < 0.001). Final height SDS was positively associated with target height and dose of GH but negatively associated with the presence of concomitant endocrinopathies and dose of spinal RT. Change in height SDS (start of GH-final height) was positively associated with male gender, younger bone age at start of GH, and dose of GH; presence of concomitant endocrinopathies and dose of spinal RT were negatively associated with change in height SDS. Risk factors associated with a final height of -2.0 sd or less included lower doses of GH and exposure to higher doses of spinal RT. Thus, to maximize final height, our findings emphasize the importance of beginning GH therapy at the earliest bone age that is clinically feasible; treating with conventional higher doses of GH; and, when possible, minimizing the dose of spinal RT.