IMPE Abstracts

Introduction: Hypogonadism has a negative impact on bone quality, increasing the risk of reduced bone mineral density (BMD) and osteoporosis. Childhood cancer survivors are at risk of hypogonadism and are commonly submitted to puberty induction (PI). BoneXpert software assesses bone age (BA) from scanned X-rays and calculates the Bone Health Index (BHI) which correlates with the BMD values measured by dual-energy x-ray absorptiometry. The aim of this study was to compare the BHI of cancer survivors with delayed puberty (DP) before and after PI.

Methods: Retrospective analysis of all pediatric patients with DP who underwent PI, with available BHI before and after PI, followed in our center between 2002 and 2022.

Results: We included 20 cancer survivor’s patients, 14 (70%) were girls. The average follow-up time was 10.1 (SD±5.9) years. The mean age of PI was 14.4 (SD±1.5) years in girls and 15.2 (SD±1.8) years in boys. In the girls’ group, 7 (50%) started treatment with 0.25mg/day of oral estradiol, 5 (35.7%) with 0.50mg/day and 1 (4.3%) with 1mg/day. In 9 (64.3%) girls, the dosage of estradiol was increased more than 1 year after the beginning of treatment. For boys, intramuscular testosterone was used for PI with an initial dosage of 50mg in 1 (16.7%), 62.5mg in 2 (33.3%) and 125mg in 3 (50%) boys. Growth hormone deficiency was diagnosed and treated in 10 of the 20 cases and 9 patients were exposed to prolonged corticosteroid therapy. Only 4 (20%) patients had calcium and vitamin D supplementation. The mean BHI standard deviation score (BHI-SDS) before treatment initiation was -1.17 (SD±1.1) and after puberty completion was -1.53 (SD±1.2). Only 6 (30%) children (5 boys) improved BHI-SDS after starting treatment for PI. In the children with improved BHI-SDS group, the mean age at cancer diagnosis was 9.2 (SD±5) years, while in the worsening BHI-SDS group was 6.8 (SD±3.7) years.

Conclusion: BHI-SDS improvement after PI was only observed in 6 (30%) children, where 83% were boys. A possible explanation is that in most girls a lower dosage of hormone for PI was used for a longer period. Furthermore, children in whom the BHI-SDS worsened had cancer diagnosed at an earlier age than the group that improved. This study highlights the importance of evaluating the BHI in children undergoing scanned X-rays for BA assessment and the implementation of measures to prevent worsening loss of BMD.