Tumour occurrence and recurrence

There is growing concern about the oncogenic potential of growth hormone (GH) used therapeutically. In rat experiments, a variety of malignant tumours have been induced following administration of supraphysiological doses of GH, whilst in other studies in hypophysectomized animals a lower than normal incidence of carcinogen-induced neoplasms was reported. In acromegaly, in which there is a pathologically sustained high GH level, there is a significantly increased incidence of cancer in general and specifically of colonic neoplasia. To determine whether the use of GH in the treatment of radiation-induced GH deficiency causes tumour recurrence, a comparison was made of tumour recurrence rates between 47 children treated with GH for radiation-induced GH deficiency after treatment for a brain tumour and a control population from the North West Children's Cancer Registry who did not receive GH (n = 160). All cases of acute lymphoblastic leukaemia (ALL), including those that were (n = 15) and were not (n = 146) treated with GH were reviewed. The computerized tomography (CT) scans in the children with brain tumours were reviewed at the time of GH commencement and subsequently. There were 5 brain tumour recurrences after GH therapy: 1 astrocytoma, 2 ependymomas and 2 medulloblastomas. Adjusting for variables other than GH which might affect tumour recurrence, the estimated relative risk of tumour recurrence was 0.82 (95% confidence interval: 0.28-2.37). In each tumour category there was no association between the use of GH and subsequent tumour recurrence.(ABSTRACT TRUNCATED AT 250 WORDS)