Growth Hormone Treatment and Risk of Second Neoplasms in the Childhood Cancer Survivor

Context: GH deficiency is common in childhood cancer survivors. In a previous report, although we did not find an increase in the risk of disease recurrence in survivors treated with GH, GH-treated survivors did have an increased risk of developing a second neoplasm (SN) (rate ratio, 3.21). Objective: In this analysis, we have reassessed the risk of GH-treated survivors developing an SN after an additional 32 months of follow-up. Design and Setting: We conducted a retrospective cohort multicenter study. Patients: Among a total of 14,108 survivors who were enrolled in the Childhood Cancer Survivor Study, a retrospective cohort of 5-yr survivors of childhood cancer, we identified 361 who were treated with GH. Main Outcome: We assessed the risk of developing an SN. Results: During the extended follow-up, five new SN developed in survivors treated with GH, for a total of 20 SN, all solid tumors. Using a time-dependent Cox model, the rate ratio of GH-treated survivors developing an SN, compared with non-GH-treated survivors, was 2.15 (95% confidence interval, 1.3–3.5; P < 0.002). Meningiomas were the most common SN (n = 9) among the GH-treated group. Conclusion: Although cancer survivors treated with GH appear to have an increased risk of developing SN compared with survivors not so treated, the elevation of risk due to GH use appears to diminish with increasing length of follow-up. Continued surveillance is essential.