Endocrine Abstracts

Survival following treatment for childhood malignancy has improved considerably over the last 40 years. Complications of treatment are frequent and although the long-term follow-up of patients is recommended, only 35% of patients are seen regularly. Endocrine complications of cancer therapy, including thyroid dysfunction, are well recognised. The aim of this study is to determine the frequency of hypothyroidism amongst the patients within the Bristish Childhood Cancer Survivor Study (BCCSS).

The BCCSS is a population based, long term follow-up study of childhood cancer survivors diagnosed between 1940 and 1991, and surviving at least five years. Self reported information on thyroid status collected by questionnaire was available for 10 091 patients.

Amongst the whole cohort 775 (7.7%) were hypothyroid. The patients at greatest risk were those treated for Hodgkin’s disease (HD) (19.9%), CNS neoplasms (15.3%), Non-Hodgkin’s lymphoma (6.2%) and leukaemia (5.2%). Patients were more likely to develop hypothyroidism if they had received radiotherapy for HD (P=0.0001) or a CNS neoplasm (P<0.00001) but not leukaemia (P=0.3). In these three patient groups the frequency of hypothyroidism was similar in men and women Patients treated for HD, CNS neoplasm and leukaemia who remained on long-term follow-up were more likely to have hypothyroidism, 25.9 vs 16.7% (P=0.004), 30.5 vs 8.0% (P<0.0001) and 7.3 vs 3.4% (P<0.0001) respectively.

Hypothyroidism is a common finding amongst adult survivors of childhood malignancy, particularly those who have received radiotherapy. The reduced frequency of hypothyroidism amongst patients not on long-term hospital follow up is of concern and suggests that the diagnosis may be missed in a substantial number of patients cared for solely in the community.