Response to GH Treatment After Radiation Therapy Depends on Location of Irradiation.
OBJECTIVES
Cancer survivors with GH deficiency (GHD) receive GH therapy (GHT) after 1+ year observation to ensure stable tumor status/resolution.


HYPOTHESIS
Radiation therapy (RT) to brain, spine, or extremities alters growth response to GHT.


AIM
Identify differences in growth response to GHT according to type/location of RT.


METHODS
The Pfizer International Growth Database was searched for cancer survivors on GHT for ≥5 years. Patient data, grouped by tumor type, were analyzed for therapy (surgery, chemotherapy, RT of the focal central nervous system, cranial, craniospinal, or total body irradiation [TBI] as part of bone marrow transplantation), sex, peak stimulated GH, age at GHT start, and duration from RT to GHT start. Kruskal-Wallis test and quantile regression modeling were performed.


RESULTS
Of 1149 GHD survivors on GHT for ≥5 years (male 733; median age 8.4 years; GH peak 2.8 ng/mL), 431 had craniopharyngioma (251, cranial RT), 224 medulloblastoma (craniospinal RT), 134 leukemia (72 TBI), and 360 other tumors. Median age differed by tumor group (P < 0.001). Five-year delta height SD score (SDS) (5-year ∆HtSDS; median [10th-90th percentile]) was greatest for craniopharyngioma, 1.6 (0.3-3.0); for medulloblastoma, 5-year ∆HtSDS 0.9 (0.0-1.9); for leukemia 5-year ∆HtSDS, after TBI (0.3, 0-0.7) versus without RT (0.5, 0-0.9), direct comparison P < 0.001. Adverse events included 40 treatment-related, but none unexpected.


CONCLUSIONS
TBI for leukemia had significant impact on growth response to GHT. Medulloblastoma survivors had intermediate GHT response, whereas craniopharyngioma cranial RT did not alter GHT response. Both craniospinal and epiphyseal irradiation negatively affect growth response to GH therapy compared with only cranial RT or no RT.
['Rose|Susan R|SR|', 'Carlsson|Martin|M|', 'Grimberg|Adda|A|', 'Aydin|Ferah|F|', 'Albanese|Assunta|A|', 'Hokken-Koelega|Anita C S|ACS|', 'Camacho-Hubner|Cecilia|C|']
D000073116:Cancer Survivors D002648:Child D005121:Extremities D005260:Female D006130:Growth Disorders D013006:Growth Hormone D006132:Growth Plate D020249:Hormone Replacement Therapy D019382:Human Growth Hormone D006801:Humans D008297:Male D009369:Neoplasms D011878:Radiotherapy D012886:Skull D013131:Spine D016896:Treatment Outcome
radiation therapy cancer survivors dose response growth hormone deficiency growth hormone therapy pediatric