Growth hormone treatment of children with brain tumors and risk of tumor recurrence

GH is increasingly used for treatment of children and adults. It is mitogen ic, however, and there is therefore concern about its safety, especially wh en used to treat cancer patients who have become GH deficient after cranial radiotherapy. We followed 180 children with brain tumors attending three l arge hospitals in the United Kingdom and treated with GH during 1965-1996, and 891 children with brain tumors at these hospitals who received radiothe rapy but not GH. Thirty-five first recurrences occurred in the GH-treated c hildren and 434 in the untreated children. The relative risk of first recur rence in GH-treated compared with untreated patients, adjusted for potentia lly confounding prognostic variables, was decreased (0.6; 95% confidence in terval, 0.4-0.9) as was the relative risk of mortality (0.5; 95% confidence interval, 0.3-0.8). There was no significant trend in relative risk of rec urrence with cumulative time for which GH treatment had been given or with time elapsed since this treatment started. The relative risk of mortality i ncreased significantly with time since first GH treatment. The results, bas ed on much larger numbers than previous studies, suggest that GH does not i ncrease the risk of recurrence of childhood brain tumors, although the risi ng trend in mortality relative risks with longer follow-up indicates the ne ed for continued surveillance.