6471 Adult Height in Male Survivors of Childhood Cancer Treated with Aromatase Inhibitors and Growth Hormone

Abstract Disclosure: N.I. Pollock: None. M. Song: None. A. Wolf: None. Y. Li: None. C. Hawkes: None. N. Motamedi: None. M.R. Denburg: None. S. Mostoufi-Moab: None. Title: Adult Height in Male Survivors of Childhood Cancer Treated with Aromatase Inhibitors and Growth Hormone Objectives: Aromatase inhibitor (AI) therapy in combination with growth hormone (GH), or as monotherapy, may have a role in improving height outcomes in male pediatric patients with GH deficiency (GHD). The effectiveness of AI therapy in the childhood cancer survivors is not known. In this retrospective study, we assess adult height (AH) in childhood cancer survivors treated with AI combined with GH therapy compared to those treated with GH alone. Methods: This was a single center retrospective cohort study of male survivors of childhood cancer treated with GH for diagnosis of GHD between 2007 and 2023. We compared AH outcomes in males treated with GH alone or in combination with off-label use of AI. Demographic and clinical characteristics, including anthropometric measurements, endocrinopathies, and cancer history, were obtained from the medical record. AH was noted as height documented at fusion of growth plates or following 18 years of age. Differences in demographic, clinical, and treatment characteristics were assessed using univariate tests of association. Multivariable regression with stepwise selection was used to examine risk factors associated with AH. All statistical analyses were performed using Stata 18.0. Results: Ninety-two patients were included; 70 were treated with GH monotherapy and 22 with combination AI/GH. Median age at AI initiation was 13.6 years (IQR 12.3-14.3) versus 11.2 years (IQR 8.6-12.9) for GH (unpaired t-test p-value <0.01; 95% CI -4.01, -1.91). A greater proportion of patients in the AI/GH group had been treated with stem cell transplantation, abdominal radiation, total body irradiation, and cis-retinoic acid (Fisher’s exact p-value <0.01). There was no statistically significant difference in AH or AH Z-score between treatment groups, with the median AH Z-score in the AI/GH group -1.95 (IQR -3.11, -0.75) versus -1.39 (IQR -2.65, 0.11) in the GH group. In multivariable linear regression, history of radiation to the spine (β= -5.9, 95% CI -11.2, -0.6), height Z-score (β= 0.3, 95% CI 0.11, 0.46), BMI Z-score (β= 3.2, 95% CI 0.95, 5.5), and advanced bone age at GH or AI treatment initiation (β= -10.1, 95% CI -17.3, -2.9) were significantly associated with AH. Conclusions: Adjunctive treatment with AI and GH was not associated with increased AH outcomes in male survivors of childhood cancer compared to GH monotherapy. Future work is needed to determine optimal adjunctive medical therapy to maximize FAH impacted by cancer therapy for this patient population. Presentation: 6/3/2024