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

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. 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.