Growth impairment in children treated for brain tumours

Dual Characters of GH-IGF1 Signaling Pathways in Radiotherapy and Post-radiotherapy Repair of Cancers

Radiotherapy remains one of the most important cancer treatment modalities. In the course of radiotherapy for tumor treatment, the incidental irradiation of adjacent tissues could not be completely avoided. DNA damage is one of the main factors of cell death caused by ionizing radiation, including single-strand (SSBs) and double-strand breaks (DSBs). The growth hormone-Insulin-like growth factor 1 (GH-IGF1) axis plays numerous roles in various systems by promoting cell proliferation and inhibiting apoptosis, supporting its effects in inducing the development of multiple cancers. Meanwhile, the GH-IGF1 signaling involved in DNA damage response (DDR) and DNA damage repair determines the radio-resistance of cancer cells subjected to radiotherapy and repair of adjacent tissues damaged by radiotherapy. In the present review, we firstly summarized the studies on GH-IGF1 signaling in the development of cancers. Then we discussed the adverse effect of GH-IGF1 signaling in radiotherapy to cancer cells and the favorable impact of GH-IGF1 signaling on radiation damage repair to adjacent tissues after irradiation. This review further summarized recent advances on research into the molecular mechanism of GH-IGF1 signaling pathway in these effects, expecting to specify the dual characters of GH-IGF1 signaling pathways in radiotherapy and post-radiotherapy repair of cancers, subsequently providing theoretical basis of their roles in increasing radiation sensitivity during cancer radiotherapy and repairing damage after radiotherapy.

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.

Transcriptome analyses reveal molecular mechanisms that regulate endochondral ossification in amphibian Bufo gargarizans during metamorphosis

BACKGROUND

A developmental transition from aquatic to terrestrial existence is one of the most important events in the evolution of terrestrial vertebrates. Amphibian metamorphosis is a classic model to study this transition. The development of the vertebrate skeleton can reflect its evolutionary history. Endochondral ossification serves a vital role in skeletal development. Thus, we sought to unravel molecular mechanisms that regulate endochondral ossification during Bufo gargarizans metamorphosis.

METHODS

The alizarin red-alcian blue double staining method was used to visualize the skeletal development of B. gargarizans during metamorphosis. RNA sequencing (RNA-seq) was used to explore the transcriptome of B. gargarizans in four key developmental stages during metamorphosis. Real-time quantitative PCR (RT-qPCR) was used to validate the expression patterns of endochondral ossification related genes.

RESULTS

Endochondral ossification increased gradually in skeletal system of B. gargarizans during metamorphosis. A total of 137,264 unigenes were assembled and 44,035 unigenes were annotated. 10,352 differentially expressed genes (DEGs) were further extracted among four key developmental stages. In addition, 28 endochondral ossification related genes were found by searching for DEG libraries in B. gargarizans. Of the 28 genes, 10 genes were validated using RT-qPCR.

CONCLUSIONS

The exquisite coordination of the 28 genes is essential for regulation of endochondral ossification during B. gargarizans metamorphosis.

GENERAL SIGNIFICANCE

The present study will not only provide an invaluable genomic resource and background for further research of endochondral ossification in amphibians but will also aid in enhancing our understanding of the evolution of terrestrial vertebrates.

GH deficiency in adult survivors of childhood cancer

Childhood cancer survivors (CCS) are a fast growing population, but late adverse effects of cancer therapies are not rare. In CCS treated with cranial radiotherapy, growth hormone deficiency (GHD) is a well-known occurrence and the potential impact of GH replacement therapy on the global outcome of CCS is under continuous evaluation. In the present review, we discuss advantages and disadvantages of GH replacement therapy in survivors of pediatric malignancies, taking into consideration the different reasons for treating GHD during childhood or adult life. It is doubtless that GH treatment is advisable to obtain a normal growth in pediatric patients. As far as the beginning/continuation of the replacement therapy in adult age is concerned, contrasting results have been reported in literature. The suggestion is that the decision to treat adult CCS should be taken after careful evaluation of each patient's clinical history and of the potential side effects, in agreement with the patients.

High prevalence of early hypothalamic-pituitary damage in childhood brain tumor survivors: need for standardized follow-up programs

INTRODUCTION

Childhood brain tumor survivors (CBTS) are at increased risk to develop endocrine disorders. Alerted by two cases who experienced delay in diagnosis of endocrine deficiencies within the first 5 years after brain tumor diagnosis, our aim was to investigate the current screening strategy and the prevalence of endocrine disorders in survivors of a childhood brain tumor outside of the hypothalamic-pituitary region, within the first 5 years after diagnosis.

PROCEDURES

Firstly, we performed a retrospective study of 47 CBTS treated in our center, diagnosed between 2008 and 2012. Secondly, the literature was reviewed for the prevalence of endocrine disorders in CBTS within the first 5 years after diagnosis.

RESULTS

Of 47 CBTS eligible for evaluation, in 34% no endocrine parameters had been documented at all during follow up. In the other 66%, endocrine parameters had been inconsistently checked, with different parameters at different time intervals. In 19% of patients an endocrine disorder was found. At literature review 22 studies were identified. The most common reported endocrine disorder within the first 5 years after diagnosis was growth hormone deficiency (13-100%), followed by primary gonadal dysfunction (0-91%) central hypothyroidism (0-67%) and primary/subclinical hypothyroidism (range 0-64%).

CONCLUSION

Endocrine disorders are frequently seen within the first 5 years after diagnosis of a childhood brain tumor outside of the hypothalamic-pituitary region. Inconsistent endocrine follow up leads to unnecessary delay in diagnosis and treatment. Endocrine care for this specific population should be improved and standardized. Therefore, high-quality studies and evidence based guidelines are warranted.

[Endocrinological outcome in children and adolescents survivors of central nervous system tumours after a 5 year follow-up]

INTRODUCTION

Given the successful increase in survival rates with the current treatments for central nervous system tumours (CNST), survivors are at high risk for late adverse effects.

PURPOSE

To evaluate the endocrine sequelae in children with CNST according to the type of tumour and treatment received.

PATIENTS AND METHODS

A retrospective review of the clinical features, auxology, hormone determinations and imaging findings of 38 patients (36.8% females, 63.2% males) with CNST, with a minimum of 5 years follow-up, was performed.

RESULTS

The mean age at diagnosis was 5.34 ± 3.07 years, with 76.3% of the patients having at least one hormone deficiency, of which growth hormone (GH) (73.7% of all patients) was the most prevalent, followed by thyrotropin (TSH) (68.4%), corticotropin (31.6%), antidiuretic hormone (28.9%), and gonadotropin (LH/FSH) (21.1%) deficiency. Precocious puberty was found in 21.1% of patients. After 5 years of follow-up, 28.9% were obese. Craniopharyngioma had more hormone deficiencies, obesity and recurrence rates. The most frequently administered treatment was surgery + chemotherapy + radiotherapy, in 47.4% of the patients. Mean final height (20 patients) was -1.2 1.6 SDS, with a mean difference of -0.53 SDS regarding their target height.

CONCLUSIONS

1) The type of tumour and treatment received influence the endocrinological sequelae. 2) The most frequent hormone deficiencies in all types of CNST, regardless of the treatment received, were GH and TSH. 3) Early diagnosis and prompt intervention of endocrine dysfunction can reduce the morbidity and improve quality of life over the long term.

Pediatric brain tumor treatment: growth consequences and their management

Tumors of the central nervous system, the most common solid tumors of childhood, are a major source of cancer-related morbidity and mortality in children. Survival rates have improved significantly following treatment for childhood brain tumors, with this growing cohort of survivors at high risk of adverse medical and late effects. Endocrine morbidities are the most prominent disorder among the spectrum of longterm conditions, with growth hormone deficiency the most common endocrinopathy noted, either from tumor location or after cranial irradiation and treatment effects on the hypothalamic/pituitary unit. Deficiency of other anterior pituitary hormones can contribute to negative effects on growth, body image and composition, sexual function, skeletal health, and quality of life. Pediatric and adult endocrinologists often provide medical care to this increasing population. Therefore, a thorough understanding of the epidemiology and pathophysiology of growth failure as a consequence of childhood brain tumor, both during and after treatment, is necessary and the main focus of this review.

Pathophysiology of radiation-induced growth hormone deficiency: efficacy and safety of GH replacement

Radiation-induced growth hormone deficiency (GHD) is primarily due to hypothalamic damage. GH secretion by the pituitary may be affected either secondary to some degree of quantitative deprivation of hypothalamic input or, if the radiation dose is high enough, by direct pituitary damage. As a consequence, the neurosecretory profile of GH secretion in an irradiated patient remains pulsatile and qualitatively intact. The frequency of pulse generation is unaffected, but the amplitude of the GH pulses is markedly reduced. Over the last 25 years, the final heights achieved by children receiving GH replacement for radiation-induced GHD have improved; these improvements are attributable to refinements in GH dosing schedules, increased use of GnRH analogues for radiation-induced precocious puberty, and a reduced time interval between completion of irradiation and initiation of GH therapy. When retested at the completion of growth, 80-90% of these teenagers are likely to prove severely GH deficient and, therefore, will potentially benefit from GH replacement in adult life. Such long-term GH treatment in patients treated previously for a brain tumor means that critical and continuous surveillance must be devoted to the risk of tumor recurrence and the possibility of second neoplasms.

Final height and body mass index among adult survivors of childhood brain cancer: childhood cancer survivor study

The objectives of this study were 1) to compare final height and body mass index (BMI) between adult survivors of childhood brain cancer and age- and sex-matched population norms, 2) to quantify the effects of treatment- and cancer-related factors on the risk of final height below the 10th percentile (adult short stature) or having a BMI of 30 kg/m(2) or more (obesity). Treatment records were abstracted and surveys completed by 921 adults aged 20-45 yr who were treated for brain cancer as children and were participants in the multicenter Childhood Cancer Survivor Study. Nearly 40% of childhood brain cancer survivors were below the 10th percentile for height. The strongest risk factors for adult short stature were young age at diagnosis and radiation treatment involving the hypothalamic-pituitary axis (HPA). The multivariate odds ratio for adult short stature among those 4 yr of age or younger at diagnosis, relative to ages 10-20 yr, was 5.67 (95% confidence interval, 3.6-8.9). HPA radiation exposure increased the risk of adult short stature in a dose-response fashion (trend test, P < 0.0001). Adjuvant chemotherapy was not an independent risk factor for adult short stature. BMI distribution in survivors did not differ appreciably from that of population norms; however, in females, young age at diagnosis and HPA radiation dose (trend test, P < 0.001) were associated with risk of obesity. Except for patients treated with surgery only, survivors of childhood brain cancer are at very high risk for adult short stature, and this risk increases with radiation dose involving the HPA. We did not find a corresponding elevated risk for obesity.

Endocrine complications of pediatric brain tumors: case series and literature review

The survival rate for childhood cancer, including brain tumors, is increasing. As a result, long-term sequelae of chemotherapy and radiotherapy are also increasing. The purpose of this study was to determine the frequency of endocrine complications of therapy for brain tumors in pediatric patients. Endocrinopathy was observed in 19 of 20 (95%) of patients with supratentorial midline tumors. Fifty-seven patients with nonmidline tumors (22 supratentorial, 35 posterior fossa) were followed for a mean of 4.6 +/- 2.4 years. Twenty-two endocrinopathies occurred in 16 patients treated as follows: one of 23 patients (0.4%) had surgery alone, zero of four (0%) had chemotherapy alone, eight of 18 (44%) had radiotherapy alone, and seven of 12 (58%) had both radiotherapy and chemotherapy. Endocrine disturbance was particularly common after craniospinal radiation (10 of 18 [55%]). Growth failure occurred in none of 23 patients who had surgery alone, in one of four patients who had chemotherapy (25%), in 11 of 18 patients who had radiotherapy (61%), in seven of 12 patients who received both radiotherapy and chemotherapy (58%), and in 12 of 18 patients who had craniospinal radiation (67%). In conclusion, endocrine and growth disturbances are uncommon with surgery alone, although they occurred in 53 and 60%, respectively, of patients treated with cranial irradiation for a brain tumor. This finding underscores the importance of routine endocrinology follow-up for all brain tumor patients receiving cranial irradiation. Literature review and endocrine surveillance recommendations are included.

Growth hormone and segmental growth in survivors of head and neck embryonal rhabdomyosarcoma

AIMS

To assess the impact of treatment for embryonal rhabdomyosarcoma on spinal growth and limb length and examine the response of these parameters to growth hormone (GH) treatment.

METHODS

We conducted a retrospective case note review of 17 survivors of head and neck rhabdomyosarcoma followed up at a single institution. All children had been treated with chemotherapy and local radiotherapy. Growth velocity, height, sitting height, and subischial limb length SDS scores were analysed.

RESULTS

Growth failure secondary to isolated GH deficiency (GHD) developed in 7/17 patients. GHD occurred at a median (range) of 3.4 (1.3-9.9) years after radiotherapy tumour doses of 46 (40-50) Gy. Growth velocity, height, and subischial limb length SDS were significantly reduced in the GHD group and improved with GH therapy.

CONCLUSIONS

GH treatment resulted in a significant improvement in sitting height SDS. We discuss the unexpected improvement in spinal growth in survivors with GHD.

Survivors of childhood cancer: long-term endocrine and metabolic problems dwarf the growth disturbance

The long-term effects of radiotherapy and chemotherapy are becoming increasingly recognized as the cure rates of certain childhood malignancies improve. The endocrine system is particularly sensitive to cancer therapies. Long-term survivors of childhood cancer who received cranial irradiation have been shown to have lower than predicted height, an increased prevalence of obesity and reductions in strength, exercise tolerance, bone mineral density, quality of life and academic achievement. Growth hormone deficiency (GHD) is the most frequent endocrine deficiency observed following cranial irradiation. Adults with GHD resulting from primary hypothalamic-pituitary disease during childhood have been shown to exhibit a clinical picture similar to that described in long-term survivors of childhood cancer: increased fat mass and reduced lean mass, strength, exercise tolerance, bone mineral density and quality of life. This review considers the possible contribution of GHD to the adverse sequelae observed in long-term survivors of childhood malignancy and includes our preliminary experience in treating 14 adults with GHD resulting from the treatment of childhood malignancies.

Preoperative chemotherapy with carboplatin alone in high risk medulloblastoma

Few studies have been carried out regarding preoperative chemotherapy utilized in the treatment of primitive neuroectodermal tumors/medulloblastomas (PNET/MB). In this paper, the authors report 3 cases of children under three years of age, with a presumed diagnosis of PNET/MB, who were preoperatively treated with chemotherapy consisting of high doses of carboplatin alone. The treatment improved the childrens' clinical condition prior to surgery and facilitated tumor removal, resulting in partial regression of the tumor. The preoperative single-drug therapy did not affect the histological diagnosis or prevent the presence of an effective degree of tumor sensitivity to the drug. All three children are still disease-free, after a mean follow-up period of 42 months.

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.

Preirradiation chemotherapy for very young children with brain tumors

Standard management of malignant brain tumors includes either surgical resection alone or surgery followed by irradiation. However, neuroaxis irradiation administered to very young children for primary intracranial tumors is often associated with major late side effects. To delay irradiation and evaluate the efficacy of preirradiation chemotherapy, we treated 9 young children (aged less than 3 years), who had newly diagnosed brain tumors and underwent total or subtotal resection, with a combination of chemotherapy including vinblastine, cisplatin, and etoposide every 3-4 weeks for 6-14 courses between 1988 and 1992. There were malignant gliomas in four patients, medulloblastomas in three, and ependymomas in two. A response to preirradiation chemotherapy (complete remission or partial remission) occurred in seven out of nine cases. Only one patient had progressive disease during the chemotherapy period. Preirradiation chemotherapy with vinblastine, cisplatin, and etoposide might be a highly effective combination allowing delay of radiation therapy in very young children with brain tumors. Acute and subacute toxicity of chemotherapy in this study was mild.

Chemotherapy with vincristine (VCR) and etoposide (VP-16) in children with low-grade astrocytoma

Twenty patients, aged 6 months to 20 years, with low-grade astrocytoma (LGA) participated in a chemotherapy trial of vincristine (VCR) and etoposide (VP-16). Fourteen children had recurrent progressive disease at entry on study. Prior treatment consisted of surgical resection alone (6), surgical resection and irradiation (4), surgical resection, irradiation and chemotherapy (2), surgery and chemotherapy (1), and irradiation and chemotherapy (1). Six patients were treated at initial diagnosis of LGA because they were less than 5 years old (5) or for a second primary tumor (1). Four recurrent patients and 3 newly diagnosed patients underwent surgical debulking of their tumors immediately prior to study entry. Tumors were located in the optic nerve/chiasm/hypothalamus (8), brain stem/cerebellum (4), cerebral hemispheres (3), midline structures (3), and spinal cord (2). The treatment plan administered in an out-patient setting consisted of weekly VCR 1.5 mg/m2 for 7 to 8 weeks and VP-16 100 mg/m2 for 5 days repeated every 6 weeks for a total of 18 months of therapy. Responses were evaluated by computerized tomography or magnetic resonance imaging. Of the 20 patients, 1 exhibited a partial response maintained for 12+ months, 3 exhibited minor responses maintained for a period of 10+ to 35 months, and 11 maintained stable disease for 10 to 42 months. Of the 11 patients with stable disease, 2 were withdrawn early from the study without further therapy. Five of the 20 patients developed progressive disease; for 4 of these 5, this occurred during the first course of therapy. Subsequently, these 5 died due to tumor.(ABSTRACT TRUNCATED AT 250 WORDS)

Growth hormone deficiency following radiation therapy of primary brain tumors in children

The medical records of 123 patients treated for brain tumors at Children's Hospital and Medical Center, Seattle, Washington, between 1985 and 1987 were reviewed. The endocrinological complications of radiation therapy and the effectiveness of growth hormone (GH) replacement therapy were assessed. These were the first 2 years after synthetic GH became available. The disease pathology was confirmed at craniotomy or biopsy in 108 patients. Ninety-five children completed radiation therapy and 65 of these were alive at the time of review; these 65 children represent the study population. The most common tumor types were medulloblastoma, craniopharyngioma, and ependymoma. Endocrine evaluation was initiated with changes in the patients' growth velocity. Patient workup included skeletal x-ray films for determination of bone and analysis of thyroxin, thyroid-stimulating hormone, and somatomedin-C levels. Following 1-dopa and clonidine stimulation, provocative studies of GH levels were performed. Growth hormone failure and short stature were observed in 26 children, most commonly in the 2nd year after tumor treatment. Eight patients with GH failure were also hypothyroid. Hormone replacement therapy was initiated with recombinant GH, 0.05 mg/kg/day, and all children so treated showed an increase in height, with eight patients experiencing catch-up growth. There were no complications of therapy or tumor recurrence. Studies of baseline bone age and somatomedin-C levels on completion of radiation therapy are recommended. Comprehensive endocrine studies should follow changes in the patients' growth velocity. With early GH replacement, catch-up growth is possible and normal adult heights may be achieved.

Efficacy of postoperative chemotherapy using cisplatin plus etoposide in young children with brain tumors

Neuraxis radiation therapy (RT) for primary intracranial tumors is associated with major late effects if administered to very young children. To control residual tumor and to delay RT, we treated eight young children (median age 6.5 months) with primary central nervous system (CNS) tumors using combination chemotherapy: cisplatin, 20 mg/M2/day plus VP-16, 75 mg/M2/day i.v. for 5 days, given q. 3-6 weeks for 8 cycles. The tumors were medulloblastoma (one), malignant ependymoma (two), primitive neuroectodermal tumor PNET (two), malignant glioma (two), astrocytoma (one). Six had measurable disease; three had positive cerebrospinal fluid (CSF) cytopathology. All patients with measurable tumor had initial objective responses (three) complete response [CR], one partial response [PR], two minor response [MR], including cytopathology (three CR of three) and metastatic deposits (two CR of two). One patient relapsed during chemotherapy. Median time to disease progression was 17.5 months; median survival was 34 months. Three patients, none of whom received RT, have prolonged progression-free intervals of 47-67 months to date. Neurodevelopmental progress continued during and after chemotherapy. Chemotherapy toxicity was mild. Median neutrophil nadir was 312/mm3, platelets 72,000. Fever during neutropenia occurred in six of 61 courses. Moderate high-frequency auditory losses were detected in three patients, and mild renal injury (GFR less than 70 ml/min) was detected in two of seven evaluable children. This pilot study demonstrates the apparent efficacy and mild toxicity of 5 day courses of cisplatin plus VP-16, with delayed RT, in young children with CNS neoplasms. A POG treatment protocol that incorporates cisplatin plus VP-16 is evaluating primary chemotherapy with delayed radiotherapy in larger numbers of pediatric brain tumor patients.

Growth and growth hormone secretion in children following treatment of brain tumours with radiotherapy

We have studied the growth of 144 children after treatment of brain tumours distant from the hypothalamo-pituitary axis. All had cranial irradiation and 87 spinal irradiation. In 56 patients observed without intervention for 3 years, height SDS in the cranial (CR) group (n = 20) declined from 0.02 to -0.44 and in the craniospinal (CS) group (n = 36) from -0.28 to -1.11. Failure of spinal growth had a marked effect in the CS group. The onset of puberty was slightly but not significantly advanced; median ages at onset of puberty were 10.3 years in girls and 12.1 years in boys. Of the total group 86.4% had clinical and biochemical evidence of growth hormone insufficiency. Fifty-two children, 33 (28 CS; 5 CR) of whom were prepubertal, received biosynthetic human growth hormone, in a dose of 15 mU/m2/week by daily injection for a period of one year. Height velocity SDS increased significantly in both groups from -2.74 to +1.90 (CS) and from -1.0 to +4.26 (CR). Spinal response to GH treatment was restricted in the craniospinal group.

Radiation and hypothalamic-pituitary function

In adults, hypopituitarism is a common consequence of external radiotherapy. The clinical manifestations may be subtle and develop insidiously many years after radiotherapy. Anterior pituitary deficiencies can therefore only be detected by regular testing, including dynamic tests of GH and ACTH reserve. Although the deficiencies most commonly develop in the order GH, gonadotrophins, ACTH then TSH, this sequence may not be predictable in an individual patient and comprehensive testing is therefore required. The tests should ideally be performed annually for at least 10 years after treatment or until deficiency has been detected and treated. It is not only the patients with pituitary disease who are at risk of developing hypopituitarism after radiotherapy. Any patient who receives a total dose of irradiation of 20 Gy or more to the hypothalamic-pituitary axis is at risk of hypopituitarism, although the threshold dose may be lower than this. This is particularly important in the long-term survivors of malignant disease in whom endocrine morbidity may be relatively common and in whom this can be easily treated, with consequent improvement in quality of life. Whilst patients who receive a high total dose of irradiation are at increased risk of developing multiple deficiencies, a higher fraction size also increases the risk of anterior pituitary failure. There is good evidence that the earliest damage to the hypothalamic-pituitary axis after external radiotherapy is at the level of the hypothalamus. However, patients who undergo pituitary ablation with interstitial radiotherapy or heavy particle beams are likely to sustain direct damage to the pituitary. In these patients, the sequence in which individual pituitary hormone deficiencies develop is generally the same as that observed with the hypothalamic damage after conventional external radiotherapy. The increasing use of radiotherapy as a means of treatment for malignant disease means that new groups of patients with potential for endocrine dysfunction are emerging. Whole body irradiation in the preparation for bone marrow transplant is one such treatment and although hypothalamic-pituitary damage appears to be confined to GH deficiency in children, longitudinal experience is limited to date, particularly in adults. The treatment of malignant disease in childhood is of particular importance in terms of the delayed endocrine sequelae. The hypothalamic-pituitary axis may not be the only endocrine tissue damaged by treatment in these patients and management is therefore more complicated. In the growing child, the potential association of growth hormone deficiency, gonadal failure or premature puberty and thyroid dysfunction mean that expert endocrine supervision is essential for optimum long-term outcome.

Improved growth response to GH treatment in irradiated children

The growth response to two years of GH treatment was studied in fifteen children after radiotherapy for a cranial tumor. The growth response was compared to that of short children (-2 SD) and that of children with idiopathic growth hormone deficiency (GHD) of similar ages. All children were treated with hGH 0.1 IU/kg/day s.c.; which is a higher dose and frequency than previously reported for irradiated children. On this protocol the growth rate increased 5.0 +/- 0.5 cm/y (mean +/- SEM) the first year and 3.8 +/- 0.7 cm/y the second year compared to the growth rate the year before GH-treatment. Although the net gain in growth was higher than previously reported, the first year growth response was significantly reduced (p less than 0.05) compared to that of GHD-children (7.6 +/- 0.5 cm/y) but exceeded (p less than 0.05) that of short children (3.4 +/- 0.3 cm/y). The median spontaneous 24 h-GH secretion was 209 mU/l in the short children, 52 mU/l in the irradiated children and 16 mU/l in the idiopathic GHD children. Thus the growth increment varied inversely to the spontaneous GH secretion observed in the three groups.

Suppressed spontaneous secretion of growth hormone in girls after treatment for acute lymphoblastic leukaemia

The spontaneous secretion of growth hormone during a 24 hour period and the response of growth hormone to growth hormone releasing hormone was studied in 13 girls who had received treatment for acute lymphoblastic leukemia that included cranial irradiation with 20-24 Gy in 12-14 fractions. At the time of investigation the girls were at varying stages of puberty and had normal concentrations of thyroid hormones. The mean interval between the end of treatment and investigation was 4.6 years. The mean age at onset of the disease was 3.2 years and at investigation 10.7 years. The average attained height equalled -0.3 SD at onset, and -1.0 SD at the time of investigation. Secretion of growth hormone was substantially reduced compared with controls and did not increase during puberty. A prompt rise in growth hormone secretion was seen after injection of growth hormone releasing hormone, but the mean maximum growth hormone concentration was, however, only 25 mU/l. There was no correlation between the 24 hour secretion and growth hormone response to growth hormone releasing hormone, or the time since irradiation. These results confirm earlier work that suggested that girls who had received treatment for acute lymphoblastic leukaemia, that included cranial irradiation, have a comparative growth hormone insufficiency characterised by normal prepubertal growth and slow growth during puberty because of an inability to respond to the increased demands for growth hormone at that time.

Growth response to growth hormone therapy following cranial irradiation

The growth response to growth hormone (GH) therapy has been studied in 12 children who received irradiation to the cranium alone either for brain gliomas, distant from the hypothalamic-pituitary axis, or as prophylaxis against CNS leukaemia. Seven children have completed GH treatment (mean duration 4 years) and five are presently on GH (mean duration 1.2 years). This response has been compared to that seen in 14 children with isolated idiopathic GH deficiency (IGHD), following GH therapy. Before treatment, the cranially irradiated patients (C-PRGHD) had higher standard deviation scores (SDS) for standing height, sitting height and leg length, and less bone age (BA) retardation, but started treatment at a similar age, and with a similar pre-treatment growth velocity and GH peak to standard provocative tests, compared to IGHD patients. GH produced a significant and similar increase in growth velocity (cm/year and SDS for BA) over the first 2 years' treatment in both groups. However C-PRGHD patients entered puberty and thus completed growth earlier than the IGHD group. As a result, cranially-irradiated children showed no change in height SDS with GH therapy, compared to catch-up growth in IGHD. Nevertheless, GH has enabled C-PRGHD patients to maintain their centile position and to achieve a more acceptable final height.

Growth response to growth hormone therapy following craniospinal irradiation

Nineteen (12 male, 7 female) children, who have received craniospinal irradiation for the treatment of a brain tumour distant from the hypothalamic-pituitary axis, resulting in growth hormone (GH) deficiency (CS-PRGHD), have been treated with GH. Eight have completed growth. Comparison has been made with the growth of seven untreated children, whose heights and growth rates at presentation were normal despite GH deficiency secondary to irradiation. GH produced a significant increase in growth velocity over the first 3 years' treatment in CS-PRGHD patients with a mean first year increment of 3 cm/year. Patients, treated to completion of growth, showed a significant increase in leg length standard deviation (SD) score (delta SDS + 0.2) compared to that of the untreated (delta SDS - 0.9) (P less than 0.05). Sitting height SD scores decreased irrespective of GH therapy (by -1.7 for the treated and -2.2 for the untreated). The onset of puberty in the irradiated patients occurred at a mean bone age of 10.7 years in males and 9.9 years in females. This limited the time available for GH therapy. These factors resulted in a decrease in standing height SDS of 0.9 at completion of GH therapy in CS-PRGHD, but a decrease of 1.7 in those not treated with GH. Thus GH therapy failed to induce "catch-up" growth in irradiated patients, but it did prevent further loss of adult stature, with a mean final height SD score of -3.4 in CS-PRGHD patients.

Long-term endocrine sequelae after surgery, radiotherapy, and chemotherapy in children with medulloblastoma

Thirteen children with medulloblastoma, were studied after 2 to 62 months off radiotherapy and chemotherapy with methotrexate and BCNU. Ages at time of study ranged from 2.3 to 15.7 years. Eleven patients, followed for a mean of 22 months, showed a significant decrease of height score, whereas nine patients had deficient growth hormone (GH) response to provocative tests. Clinical pubertal progression was normal in all patients, and three of five girls with advanced pubertal development had menarche. No evidences of gonadotropin disturbances were found in five patients whereas seven had raised basal follicle-stimulating hormone (FSH) level or FSH response to luteinizing hormone-releasing hormone (LH-RH). Abnormalities in thyrotrophin (TSH) secretion were found in 9 of 13 patients. This study shows that poor growth and GH deficiency were frequent in our patients. The high frequency of thyroid disturbances observed point out the need of evaluating thyroid function for adequate replacement therapy. Perhaps modification of adjuvant chemotherapy in the future can diminish drug-induced gonadal damage.

Irradiation-induced growth failure

Short stature may complicate the treatment during childhood of brain tumours and, to a lesser extent, ALL. A number of factors may be responsible, including spinal irradiation, malnutrition, recurrent tumour, chemotherapy, precocious puberty and radiation-induced GH deficiency. GH is always the first pituitary hormone to be affected by radiation damage to the hypothalamic-pituitary axis but larger radiation doses may result in panhypopituitarism. Some children retain normal GH responses to certain provocative stimuli, although physiological GH secretion is reduced. Nonetheless, in children suspected of radiation-induced GH deficiency, pharmacological tests of GH secretion remain useful, the ITT being the test of choice because of the marked radiation sensitivity of the GH response to hypoglycaemia. The hypothalamus is more radiosensitive than the pituitary. In many patients with radiation-induced GH deficiency, the damage appears to be at the hypothalamic level resulting in a deficiency of endogenous GRF. Treatment with synthetic GRF may provide an alternative to GH therapy in such children. Finally, there is no evidence to suggest that GH therapy given to a child with radiation-induced GH deficiency might induce a brain tumour recurrence or a relapse of ALL.

Late effects after treatment of twenty children with soft tissue sarcomas of the head and neck. Experience at a single institution with a review of the literature

Twenty children with soft tissue sarcomas of the head and neck, treated at the Children's Hospital of Philadelphia and the Hospital of the University of Pennsylvania from 1972 to 1981, were evaluated for the late deleterious effects of treatment. All patients received radiation therapy and combination chemotherapy with vincristine, dactinomycin, and cyclophosphamide; certain patients also received Adriamycin (doxorubicin). All had ophthalmologic, otologic, growth, and cosmetic evaluations; 15 also had dental and maxillofacial examinations. The median age at diagnosis was 6 years (range, 7 months-13 years). Median follow-up from time of diagnosis was 5.5 years with a minimum of 3 years in all but four patients. The major problems encountered were related to the eyes (xerophthalmia and cataracts), ears (hearing loss), teeth (maleruption and caries), glandular structures (xerostomia, hypopituitarism), and development (craniofacial deformity). It is concluded that children treated for soft tissue sarcomas of the head and neck with combined modality therapy, including radiation enhancers, may show a variety of late treatment-related adversities. These children require close multidisciplinary follow-up for detection of late effects in order that appropriate prophylactic or symptomatic treatment can be instituted to minimize their consequences.

Chiasmatic optic glioma treated with chemotherapy. A preliminary report

Chiasmatic optic glioma is a rare tumor with an erratic natural history, usually seen in young children. A prior study from this institution demonstrated that these lesions were frequently lethal, despite initial clinical stabilization following radiation therapy, and that visual, intellectual, and late endocrinological disabilities were prevalent. A novel approach was developed in 1977, when an initial clinical response to vincristine was recorded in a child with a recurrent optic glioma. Since then, all children with recurrent optic glioma and all children aged 6 years old and under with newly diagnosed optic glioma have been offered a program of initial therapy with vincristine and actinomycin D for six cycles over 18 months. The four children with recurrent tumor who were treated with that regimen remain clinically stable 13 to 115 months after chemotherapy. Twelve children (eight under 24 months old) with newly diagnosed optic glioma have been treated with this program, and three are still on therapy. Four developed progression while on therapy, and five remain stable from 1 to 60 months posttherapy. The four children who developed progressive disease have been treated with radiation therapy and remain stable. Six of the 12 children showed shrinkage of their tumor on computerized tomography while receiving chemotherapy. This program may serve as an alternative to initial radiation therapy in young children.

Long-term effects of cranial irradiation on endocrine function in children with brain tumors. A prospective study

This study prospectively evaluated the endocrine function of 11 children treated with cranial irradiation (CRT) for brain tumors. All tumors were remote from the hypothalamic-pituitary axis. Children were studied before treatment and at 3, 6, and 12 months after the completion of CRT. T4, thyroid-stimulating hormone, prolactin, plasma cortisol, and urinary follicle-stimulating hormone and luteinizing hormone values were normal before and after treatment in all patients. Growth hormone (GH) deficiency was identified in 0 of 7 patients before treatment, in 2 of 7 patients 3 months post-CRT, in 9 of 11 patients 6 months post-CRT, and in 7 of 8 patients 12 months post-CRT. Growth deceleration was identified in five of seven prepubertal patients. GH deficiency is an extremely common sequelae of CRT, beginning as early as 3 months after the completion of CRT. The deficit is progressive over time.

Height attainment in children with steroid-responsive nephrotic syndrome

The heights of 80 patients with steroid-responsive nephrotic syndrome (SRNS) were measured 5-24 years after diagnosis. During childhood most patients had received repeated courses of high-dose corticosteroids and prolonged maintenance therapy. Although at the time of taking corticosteroids growth was suppressed, those who had completed growth had a mean height standard deviation score (SDS) of -0.22, equivalent to a height on the 40th centile. Total corticosteroid dose prescribed was correlated only weakly with height SDS; there was no correlation between total dose and height when the post-pubertal patients were studied separately, indicating that their ultimate height attainment was not affected significantly.

The long-term effects of cranial irradiation on the central nervous system

Cranial irradiation and chemotherapy may have significant long-term deleterious effects on children with brain tumors. Intellectual deterioration, endocrinopathies, leukoencephalopathy, extraneural metastases, and oncogenesis may all complicate the treatment of central nervous system neoplasia. These long-term effects of therapy have important implications, as some are amenable to treatment and others may be prevented by the careful monitoring of drug and radiation administration. Until recently, the survivals of children with brain tumors were limited, so that concerns over long-term effects of therapy were unnecessary. As children with certain types of brain tumors now have a better prognosis, these long-term and possibly remediable effects have important implications. This article emphasizes radiation effects on intellect, endocrine function, and oncogenesis. Recommendations for baseline and longitudinal evaluations of children with brain tumors are suggested.

Hypothalamic growth hormone releasing factor deficiency following cranial irradiation

The effect of synthetic human pancreatic tumour GH releasing factor (hp GRF1-44) on GH release has been studied in 10 patients with radiation-induced GH deficiency and four normal subjects. All 10 patients showed subnormal GH responses to both an ITT (median peak GH 3.2 mU/l) and to arginine stimulation (median peak GH 2.9 mU/l), although the remainder of pituitary function was intact. Following an acute intravenous bolus (100 micrograms) of hp GRF1-44, there was no GH response in two patients and a subnormal but definite GH response in a further four. The remaining four patients showed a significant GH response (median peak GH level 29 mU/l; range 22-57 mU/l) to hp GRF1-44, similar in magnitude and timing to that seen in the four normals. This strongly suggests that in these four subjects, the discrepancy in GH responses to hp GRF1-44, ITT and to arginine was a result of radiation-induced hypothalamic damage leading to a deficiency of endogenous GRF. The availability of synthetic hp GRF capable of stimulating GH secretion means that the distinction between hypothalamic and pituitary causes of GH deficiency will be of considerable therapeutic importance in the future.

Follow-up of children with brain tumors

One hundred two patients were evaluated for late effects of brain tumor in childhood by a medical record review and follow-up questionnaire. The patients had survived brain tumor for 5 to 47 years (median, 18 years). Among 30 patients who had received brain irradiation, 3 were successfully treated for second neoplasms that developed within the radiotherapy field 11, 16, and 29, years later, respectively. Moderate or severe functional deficits were present in 24 patients (24%), more commonly among those treated before 2 years of age and among those with cerebral astrocytoma. The other 78 patients (76%) had mild or no gross deficits, and all but 1 of them were attending school or were employed. Twenty-one patients in the series reported a total of 41 offspring, none of whom had cancer or mental retardation. Although markedly diverse performance levels were found among the 102 long-term survivors of childhood brain tumors, the majority had an acceptable quality of life.

Reduced pulsatile growth hormone secretion in children after therapy for acute lymphoblastic leukemia

Basal growth hormone levels were measured every 20 minutes over 24 hours in eight long-term survivors of acute lymphoblastic leukemia and in 13 age- and pubertal stage-matched normal children. Among the patients, the median total basal growth hormone output (AUC) was 43 units, compared with 341 units in the normal control group (P less than 0.001). In the patients, mean pulse amplitude (6.9 ng/ml) and frequency (4.6) over 24 hours also were reduced, compared with the control values (32 ng/ml and 8.5, P less than 0.001 and P less than 0.05, respectively). In addition, normal children secreted more GH at night (median AUC 280) than during the day (113, P less than 0.001). However, this diurnal pattern was absent in three of the patients studied. These data suggest that perturbations of spontaneous pulsatile GH secretion are common after standard therapy for ALL and may be a sensitive means of detecting therapy-related neuroendocrine damage. Blunting of spontaneous pulsatile GH secretion may contribute to the abnormalities in growth seen in children with ALL.

Long-term effects of treatment on endocrine function in children with brain tumors

Fourteen children with brain tumors received endocrine evaluations at least one year following completion of cranial irradiation. Treatment consisted of operation (13 patients), craniospinal irradiation (6), whole brain irradiation (5), posterior fossa irradiation (3), and chemotherapy (10). Endocrine evaluation included bone age roentgenography and measurement of growth hormone (using sequential arginine and insulin stimulation), thyroxine, thyroid-stimulating hormone, plasma cortisol, testosterone, prolactin, and urinary follicle-stimulating hormone and luteinizing hormone. Ten of 12 children (83%) had abnormal responses to both tests of growth hormone stimulation. All growth hormone-deficient patients treated prior to puberty and tested at least 2 years following completion of cranial irradiation had decelerated linear growth. Results of thyroid function tests were abnormal in 4 patients: 2 patients had evidence of primary hypothyroidism, and 2 showed secondary or tertiary hypothyroidism. Two patients had inadequate cortisol responses to insulin hypoglycemia. Urinary follicle-stimulating hormone and luteinizing hormone, serum prolactin, and serum testosterone levels were appropriate for age in all patients.

Growth and endocrine function after treatment for medulloblastoma

Children with medulloblastoma in Bristol are treated surgically and with craniospinal irradiation, and in some cases chemotherapy. Thirteen medium or long term survivors were investigated to determine their growth and endocrine function. Their rate of growth was considerably reduced through the first year of their illness and after spinal irradiation spinal growth was poor. Nine children developed growth hormone deficiency. They were clinically euthyroid but 7 had raised basal thyroid stimulating hormone values. Gonadal function was abnormal in all but the youngest child. The rate of survival is increasing in children with medulloblastoma but this is associated with appreciable endocrine abnormalities. Some of these problems are present shortly after treatment ends but others may develop later and long term surveillance is therefore essential.

Assessment of the long-term effects of primary radiation therapy for brain tumors in children

One-hundred-twelve children with primary brain tumors received definitive radiotherapy between the years 1958--1979. Sixty-nine patients were alive at intervals of 1--21 years. Thirty-eight patients underwent neurologic and endocrine evaluation, psychologic and intelligence testing, and assessement for second malignancy post-treatment. A second intracranial malignancy developed in one child, for an incidence of 1.6%. Performance status was good to excellent in 89% of the patients studied. Seventeen percent of the group were mentally retarded. Behavioral disorders were identified in 39% of the patients, 59% of the mothers, and 43% of the fathers. Of the 23 patients with nonparasellar tumors, six were found to have growth hormone deficiency, including two patients with panhypopituitarism. Disability was related to age under 3 years at the time of treatment and tumor extension to the hypothalamus.

The effects of growth hormone therapy in children with radiation-induced growth hormone deficiency

The effects of growth hormone (GH) therapy were studied in 6 children, previously treated for brain tumours which did not directly involve the hypothalamic-pituitary axis, and who had received cranial irradiation between 2.1 and 10 years earlier. All 6 were short with a standing height standard deviation score (SDS) from -1.7 to -3.3. Impaired growth hormone responses to an insulin tolerance test (ITT) were observed in all 6 and to a Bovril stimulation test in 5 children. The remainder of pituitary function was essentially normal. All 6 were prepubertal and 5 had a retarded bone age. During the pre-treatment year the 6 children's growth rates varied fom 2.0 to 5.1 cm. Subsequently all received human GH in a dose of 5 units 3 times weekly for 1 year. The growth rate in each was at least 2 cm greater during the treatment year than the pre-treatment year. Growth during the treatment year ranged from 6.0 to 10.1 cm. In 5 of the 6 the improvement in growth rate could be totally ascribed to the GH therapy. In the sixth there was significant pubertal maturation during the treatment year and only in this subject did the bone age advance at a significantly greater rate than the chronological age.