Abnormal insulin response to glucose following treatment for Wilms' tumor in childhood.

UNLABELLED: To determine whether beta-cell function could be impaired by the treatment for Wilms' tumour (WT) in childhood. We investigated the insulin secretion of 44 survivors of WT (22 males) with a median off-treatment follow up of 8.3 years (range 1-19.8). All patients had an intravenous glucose tolerance test (IVGTT) (0.5 gm/kg, max 25 g) to determine the first-phase insulin response (FPIR) (sum of the 1- and 3-min insulin concentrations). Median age at the time of the study was 12.7 years (range 4.2-22.7). Eight subjects (7 males) had a FPIR value below the 3rd percentile, and 7 (3 males) above the 97th centile. Among the 22 patients who received radiotherapy. 7 (6 males) showed a FPIR < 3rd percentile versus only 1 (a male) of the 22 patients who received no radiation (31.8% vs 4.5%; P < 0.05). Analysis of variance showed that the time elapsed since therapy had a significant role on the development of low FPIR only in males. The 7 patients with an insulin release > 97th percentile did not show any significant difference compared to subjects with lower insulin values for weight, age at diagnosis, sex, time elapsed since treatment, radiotherapy and chemotherapy protocol.
CONCLUSION: An impaired insulin response is evident in some patients treated for WT in childhood, mainly in male patients who received abdominal radiotherapy and were examined a longer time after therapy. We hypothesize that this decreased insulin release is related to damage due to radiotherapy and therefore a careful follow up is recommended in adulthood in these patients.