Improved growth response to GH treatment in irradiated children

GH deficiency in cancer survivors in the transition age: diagnosis and therapy

BACKGROUND

Survival rates among childhood cancer survivors (CCSs) have significantly risen in the last 40 years due to substantial improvements in treatment protocols. However, this improvement has brought with it serious late effects that frequently involve the endocrine system. Of the endocrine disorders, GH deficiency (GHD) is the most common among CCSs as a consequence of a history of cancers, surgery, and/or radiotherapy involving the hypothalamo-pituitary region.

METHODS

A comprehensive search of English language articles regardless of age was conducted in the MEDLINE database between December 2018 and October 2019. We selected all studies on GH therapy in CCSs during the transition age regarding the most challenging topics: when to retest; which diagnostic tests and cut-offs to use; when to start GH replacement therapy (GHRT); what GH dose to use; safety; quality of life, compliance and adherence to GHRT; interactions between GH and other hormonal replacement treatments.

RESULTS

In the present review, we provide an overview of the current clinical management of challenges in GHD in cancer survivors in the transition age.

CONCLUSIONS

Endocrine dysfunction among CCSs has a high prevalence in the transition age and increase with time. Many endocrine disorders, including GHD, are often not diagnosed or under-diagnosed, probably due to the lack of specialized centers for the long-term follow-up. Therefore, it is crucial that transition specialized clinics should be increased in terms of number and specific skills in order to manage endocrine disorders in adolescence, a delicate and complex period of life. A multidisciplinary approach, also including psychological counseling, is essential in the follow-up and management of these patients in order to minimize their disabilities and maximize their quality of life.

GH Therapy in Childhood Cancer Survivors: A Systematic Review and Meta-Analysis

BACKGROUND

GH deficiency (GHD) is common among childhood cancer survivors (CCSs) with history of tumors, surgery, and/or radiotherapy involving the hypothalamus-pituitary region. We aimed to evaluate the effects of GH therapy (GHT) in CCSs on adult height, risk of diabetes mellitus, abnormal lipids, metabolic syndrome, quality of life, secondary tumors, and disease recurrence.

METHODS

We searched multiple databases for randomized and observational studies. Pairs of reviewers independently selected studies and collected data. Random effects meta-analysis was used to pool outcomes across the studies.

RESULTS

We included 29 observational studies at moderate to high risk of bias. Sixteen studies compared CCSs on GHT with those not on GHT (512 patients, GH dose: 0.3 to 0.9 IU/kg/week). GHT was significantly associated with height gain [standard deviation score, 0.61; 95% CI, 0.08 to 1.13] and was not significantly associated with the occurrence of secondary tumors [odds ratio (OR), 1.10; 95% CI, 0.72 to 1.67] or tumor recurrence (OR, 0.57; 95% CI, 0.31 to 1.02). Thirteen studies compared CCSs on GHT with normal age- or sex-matched controls or controls with idiopathic GHD or short stature. GHT was associated with either improved or unchanged risk of diabetes, lipid profiles, and metabolic syndrome. GHT was associated with improvements in quality of life.

CONCLUSION

CCSs treated with GHT gain height compared with the untreated controls. GHT may improve lipid profiles and quality of life and does not appear to increase the risk of diabetes or the development of secondary tumors, although close monitoring for such complications remains warranted due to uncertainty in the current evidence.

Long-term effects of radiation therapy on cognitive and endocrine function in children with leukemia and brain tumors

BACKGROUND

As the number of long-term survivors of childhood cancer has grown, it has become increasingly clear that central nervous system therapy may have serious long-term effects on cognition and endocrine function. These complications have been studied most extensively in children with brain tumors and leukemia.

REVIEW SUMMARY

Children with acute lymphoblastic leukemia previously treated with cranial irradiation are at risk for cognitive decline. Chemotherapy-only regimens, which rely on high-dose frequently administered methotrexate, are also associated with producing cognitive dysfunction. Children irradiated for brain tumors are even more vulnerable. Risk factors include perioperative morbidity, young age, large-volume high-dose cranial irradiation, supra-tentorial location of tumor, moyamoya syndrome, and leukoencephalopathy. Cognitive decline is progressive over at least a decade. The most common radiation-induced endocrinopathies are hypothyroidism and growth hormone deficiency. Treatment effects on growth are multifactorial and include growth hormone deficiency,spinal shortening, precocious puberty, undetected hypothyroidism,and poor nutrition. Fifty percent to 80% of children treated with craniospinal radiation for brain tumors will experience growth failure. In hopes of reducing neurotoxicity, current treatments limit the dose and volume of radiation while adding chemotherapy. Results have not been uniformly positive, however, and may increase toxicity in some cases.

CONCLUSIONS

The standard of care in 2004 is that children who have been treated for brain tumors and leukemia should be monitored for cognitive and endocrine dysfunction. Until effective non-neurotoxic treatment is identified, long-term effects assessments are essential to maximize the quality of life of survivors of childhood cancer.

Disturbances in oral and dental structures in patients with pediatric lymphoma after chemotherapy: a preliminary report

OBJECTIVE

The purpose of this study was to evaluate the effects of chemotherapy on oral and dental structures and craniofacial growth in 30 survivors of childhood lymphoma.

STUDY DESIGN

Eruption status, root malformations, premature apexification, agenesis, crown anomalies, soft tissue abnormalities, gingival and periodontal status, enamel defects and discolorations, and craniofacial growth status of the subjects were documented and compared with findings in 20 healthy children who served as controls.

RESULTS

Statistically significant (P < .05) differences between the study and control groups were found for plaque index, enamel hypoplasias, discolorations, and agenesis.

CONCLUSIONS

The results of the study suggest that antineoplastic therapy and/or childhood cancer can result in a higher prevalence of various malformations in teeth. Children treated in the early years of their lives displayed the most severe dental defects, suggesting that immature teeth are at a greater risk of developmental disturbances than fully developed teeth.

Growth hormone treatment in irradiated children with brain tumors

We assessed the efficacy of GH treatment in 25 GH deficient patients irradiated for brain tumors (eight with glioma cranio-irradiated, eleven with medulloblastoma and six with ependymoma craniospinal-irradiated). We administered GH at doses of 0.6-0.9 IU/kg/week for one to three years at least two years after diagnosis of the tumor. We assessed the efficacy of the treatment each year by comparing the values of height velocity over bone age and change in the ratios progression of chronological age/progression of bone age and progression of statural age/progression of bone age. The treatment promoted satisfactory growth; better results were obtained in patients with glioma, who received cranial irradiation only, than in those with medulloblastoma or ependymoma, who received spinal irradiation as well. Moreover, the growth prognosis improved, especially in the cranio-irradiated patients. In our series of patients four presented tumor recurrence; these results did not differ significantly from those in irradiated patients with cerebral tumors who were not treated with GH.

Effect of chemotherapy on growth

Growth restriction has been demonstrated clearly following the treatment of childhood malignancies, even in the absence of irradiation to the hypothalamic-pituitary axis. The use of CT and spinal irradiation in the original treatment of brain tumours has a marked effect on growth. This effect is most profound in children who have received both treatments and cannot be overcome using GH therapy at conventional doses.

Growth and puberty after growth hormone treatment after irradiation for brain tumours

The impact of treatment with either cranial or craniospinal irradiation with or without cytotoxic chemotherapy for a brain tumour distant from the hypothalamic-pituitary axis was assessed in 29 children who had reached final height. All had received growth hormone treatment for radiation induced growth hormone deficiency. Final height, segmental growth during puberty, and duration of puberty were studied. Both craniospinal irradiation and the use of chemotherapy resulted in a significant and equal reduction in final height; this effect in those children who received both craniospinal irradiation and chemotherapy was additive. The degree of height loss was related to the age at irradiation, the most profound effect on final height occurring in the youngest at irradiation. The mean duration of puberty from G2-G4/B2-B4 (1.97 years) was not significantly different from the duration of puberty in normal children. Growth hormone increases growth velocity in children with radiation induced growth hormone deficiency but their final height is significantly less than their mid-parental height. The use of spinal irradiation and chemotherapy in the original treatment of brain tumours has a marked effect on growth which is not overcome with the use of growth hormone treatment in current doses. Early puberty of normal duration contributes to poor growth.

Changes in craniofacial development induced by growth hormone therapy in children treated with bone marrow transplantation

The effect of growth hormone (GH) treatment on craniofacial development was studied in nine children exhibiting low growth velocity after bone marrow transplantation (BMT). Comparisons were made with seven BMT children who had not received GH. Two groups of age- and sex-matched healthy children served as controls for the respective patient groups. After an average observation period of 3.5 years, the BMT children not treated with GH exhibited significantly reduced mandibular length and alveolar height (p < 0.01). The increase in mandibular length was only 30% of that found in healthy controls. Maxillary growth was less affected by BMT treatment. In the GH treated group, no significant differences were found in craniofacial growth increments compared with controls. Although exogenous GH therapy in this group of children did not induce a catch-up growth, it appears to have prevented further loss in growth potential.

Changes in the approach to central nervous system tumors in childhood

Current approaches to children with brain tumors are in a state of evolution. Currently, 50% of children with all types of brain tumors may be expected to survive 5 years. Therefore, the goals of neuro-oncology have broadened to include improved survival and improved quality of life. This article reviews changes in therapy that have altered survival as well as changes in therapy as a consequence of increasing recognition of complications and toxicity of treatment.

Irradiation-induced growth failure

GH deficiency, skeletal disproportion and early or precocious puberty may complicate irradiation to the head or axial skeleton in childhood. Certain cohorts of children are at particular risk, including those irradiated for brain tumours and various haematological malignancies. Both GH deficiency and impaired spinal growth may result in short stature, whereas the occurrence of early puberty in association with GH deficiency reduces the time available for GH therapy. The age of the child at irradiation is critical in that, in younger children, the central nervous system is more radiosensitive, the severity of the subsequent skeletal disproportion is greatest and the onset of puberty earliest. It is the very young craniospinally-irradiated child who is most at risk of extreme short stature.

Long-term consequences of CNS treatment for childhood cancer, Part II: Clinical consequences

Survival of children with brain tumors has improved over the past 20 years due in part to advances in surgery, radiation, and most recently chemotherapy. The long-term adverse effects of radiation and chemotherapy on these children is the subject of this report. In Part I, we reviewed the pathologic consequences of radiation, including leukoencephalopathy, radiation necrosis, and radiation myelopathy as well as the oncogenic effects of both radiation and chemotherapy. Part II addresses the long-term consequences of radiation and chemotherapy on intellectual and endocrine function. Risk factors for the development of both endocrinopathies and intellectual dysfunction include age at the time of radiation, volume and dose of radiation, site of tumor, and use of adjuvant chemotherapy, in particular methotrexate. Early recognition of these complications and treatment, where indicated, will measurably improve the quality-of-life of children treated for brain tumors. The national cancer groups are currently attempting to limit these long-term adverse effects by taking risk factors into account when formulating new treatment regimens.