Endocrine Abstracts

Introduction: The clinical relevance of low IGF-I levels, caused by cranial radiotherapy, in adult childhood cancer survivors has not been studied extensively. We evaluated whether IGF-I is a useful marker for altered body composition and growth hormone deficiency in this group.

Methods: We analyzed retrospective data from 610 adult childhood cancer survivors, retrieved from the late effects clinic. Median age at diagnosis was 6 years (interquartile range 3–11) and follow-up time was 18 years (13–24). We assessed IGF-I standard deviation scores (SDS), anthropometrical measures, growth hormone stimulation tests in patients with clinical signs of GHD and measures of body composition (assessed by dual X-ray absorptiometry, Lunar Prodigy).

Results: In 58 cranially irradiated acute leukemia survivors (25 Gy (24–25)) and 56 locally irradiated brain tumor survivors (42 Gy (35–54)) we found significantly lower IGF-I SDS (P<0.001), lower height SDS (P<0.001), higher body mass index (P=0.01), higher waist-hip ratio (P=0.001), higher total fat percentage SDS (P<0.001) and lower lean body mass SDS (P<0.001), as compared to 452 not cranially irradiated survivors. IGF-I showed a weak inverse correlation with BMI (r=−0.12, P=0.04), waist hip ratio (r=−0.15, P=0.01), total fat percentage (r=−0.14, P=0.02) and a positive correlation with lean body mass (r=0.15, P=0.01). In patients with low IGF-I levels, IGF-I did not significantly differ between subjects with and without GHD as determined by GH-stimulation testing (P=0.39).

Conclusion: This study shows that IGF-I has limited value as a marker for alterations in body composition in adult childhood cancer survivors.

Declaration of interest: The authors declare that there is no conflict of interest that could be perceived as prejudicing the impartiality of the research project.

Funding: This research did not receive any specific grant from any funding agency in the public, commercial or not-for-profit sector.