Early development of endocrine and metabolic consequences after treatment of central nervous system tumors in children

Hypothalamic-Pituitary and Other Endocrine Surveillance Among Childhood Cancer Survivors

Endocrine disorders in survivors of childhood, adolescent, and young adult (CAYA) cancers are associated with substantial adverse physical and psychosocial effects. To improve appropriate and timely endocrine screening and referral to a specialist, the International Late Effects of Childhood Cancer Guideline Harmonization Group (IGHG) aims to develop evidence and expert consensus-based guidelines for healthcare providers that harmonize recommendations for surveillance of endocrine disorders in CAYA cancer survivors. Existing IGHG surveillance recommendations for premature ovarian insufficiency, gonadotoxicity in males, fertility preservation, and thyroid cancer are summarized. For hypothalamic-pituitary (HP) dysfunction, new surveillance recommendations were formulated by a guideline panel consisting of 42 interdisciplinary international experts. A systematic literature search was performed in MEDLINE (through PubMed) for clinically relevant questions concerning HP dysfunction. Literature was screened for eligibility. Recommendations were formulated by drawing conclusions from quality assessment of all evidence, considering the potential benefits of early detection and appropriate management. Healthcare providers should be aware that CAYA cancer survivors have an increased risk for endocrine disorders, including HP dysfunction. Regular surveillance with clinical history, anthropomorphic measures, physical examination, and laboratory measurements is recommended in at-risk survivors. When endocrine disorders are suspected, healthcare providers should proceed with timely referrals to specialized services. These international evidence-based recommendations for surveillance of endocrine disorders in CAYA cancer survivors inform healthcare providers and highlight the need for long-term endocrine follow-up care in subgroups of survivors and elucidate opportunities for further research.

Prevalence and Risk Factors for Endocrine Disorders in Childhood Brain Tumors From a Single Tertiary Center in Malaysia

Patients with childhood brain tumors are at risk of endocrine disorders. The prevalence of endocrine disorders varies across the world but is unknown in Malaysia. This study's objectives were to determine the prevalence of endocrine disorders among children with brain tumors in Malaysia and to identify endocrinopathy-associated risk factors. We retrospectively reviewed the clinical data of pediatric patients with brain tumors diagnosed and treated at the University Malaya Medical Center from 1 January 2001 to 31 December 2015, with a follow-up period until the age of 18 years old or at least 3 years from the initial diagnosis. A total of 106 patients were included; 71 patients (66%) were screened for endocrine disorders, and 61% of these had endocrine disorders at a median follow-up of 4 years. Hypothyroidism, short stature, and adrenocortical insufficiency were present in one-third of the patients, followed by central diabetes insipidus (21%), growth hormone deficiency (10%), delayed puberty (9%), and precocious puberty (4%). Radiation therapy and surgical intervention were risk factors for endocrine disorders, but hydrocephalus, supratentorial tumors, and malignant tumors were not. Most endocrinopathies developed within the first 2 years of brain tumor diagnosis. Therefore, standard endocrine-monitoring guidelines aiming for early diagnosis and therapy are essential.

Comparison of hypothyroidism, growth hormone deficiency, and adrenal insufficiency following proton and photon radiotherapy in children with medulloblastoma

BACKGROUND

Endocrine deficiencies are common following Craniospinal irradiation (CSI) in children with brain tumors, but empirical data comparing outcomes following proton (PRT) and photon radiation therapy (XRT) are limited.

METHODS

This retrospective chart review compared the incidence of hypothyroidism, Growth hormone deficiency (GHD), and Adrenal insufficiency (AI) in patients with medulloblastoma treated with XRT and PRT between 1997 and 2016. All patients received CSI and had routine endocrine screening labs to evaluate for thyroid dysfunction, GHD, and AI. We used proportional hazards regression to calculate hazard ratios (HR) and 95% confidence intervals (CI) comparing the development of hypothyroidism, AI, and GHD between radiation modalities, adjusting for age at diagnosis, sex, race/ethnicity, and CSI dose.

RESULTS

We identified 118 patients with medulloblastoma who were followed for a median of 5.6 years from the end of radiotherapy. Thirty-five (31%) patients developed hypothyroidism, 71 (66%) GHD, and 20 (18%) AI. Compared to PRT, XRT was associated with a higher incidence of primary hypothyroidism (28% vs. 6%; HR = 4.61, 95% CI 1.2-17.7, p = 0.03). Central hypothyroidism, GHD, and AI incidence rates were similar between the groups.

CONCLUSIONS

Primary hypothyroidism occurs less often after PRT CSI, compared to XRT CSI. This suggests that the thyroid and pituitary glands receive less radiation after spine and posterior fossa boost RT, respectively, using PRT.

Metabolic Disturbances in Children Treated for Solid Tumors

Metabolic disturbances are among the most common disorders diagnosed in pediatric patients after anti-cancer therapy (ACT). The aim of our study was to evaluate the prevalence of metabolic disturbances among patients after ACT. The study group comprised 44 patients (31 boys) treated for solid tumors and 31 patients in the control group. Body weight, height, body mass index (BMI) values, lipid parameters are expressed in Standard Deviation Score (SDS), based on centile charts. Indicators of risk to atherosclerosis were calculated. Obesity/overweight was observed in one third of the patients. Hypercholesterolemia occurred in half of them, elevated tryglicerides (TG) SDS in 11, and elevated low-density lipoprotein cholesterol (LDL-C) SDS in nine of the patients. Increased levels of both cholesterol SDS and LDL SDS were found in nine patients and four of them also showed elevated levels of TG SDS. There were significant differences in lipid parameters between the sexes. Risk indicators of lipid disorders defined by statistical distances (τ) were determined for the study group and the control group. The sum of the risk ratios of lipid disorders in the study group was 150 times higher than in the control group. Patients after ACT require special monitoring of lipids profiles and thyroid function as they are at higher risk for dyslipidemia and atherosclerosis than healthy people.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Less known aspects of central hypothyroidism: Part 1 - Acquired etiologies

Central hypothyroidism (CH) is a rare cause of hypothyroidism. CH is frequently overlooked, as its clinical picture is subtle and includes non-specific symptoms; furthermore, if measurement of TSH alone is used to screen for thyroid function, TSH concentrations can be normal or even above the upper normal reference limit. Indeed, certain patients are at risk of developing CH, such as those with a pituitary adenoma or hypophysitis, those who have been treated for a childhood malignancy, have suffered a head trauma, sub-arachnoid hemorrhage or meningitis, and those who are on drugs capable to reduce TSH secretion.

The hypothalamic-pituitary-adrenal axis in childhood cancer survivors

Endocrine abnormalities are common among childhood cancer survivors. Abnormalities of the hypothalamic-pituitary-adrenal axis (HPAA) are relatively less common, but the consequences are severe if missed. Patients with tumours located and/or had surgery performed near the hypothalamic-pituitary region and those treated with an accumulative cranial radiotherapy dose of over 30 Gy are most at risk of adrenocorticotrophic hormone (ACTH) deficiency. Primary adrenal insufficiency may occur in patients with tumours located in or involving one or both adrenals. The effects of adjunct therapies also need to be considered, particularly, new immunotherapies. High-dose and/or prolonged courses of glucocorticoid treatment can result in secondary adrenal insufficiency, which may take months to resolve and hence reassessment is important to ensure patients are not left on long-term replacement steroids inappropriately. The prevalence and cumulative incidences of HPAA dysfunction are difficult to quantify because of its non-specific presentation and lack of consensus regarding its investigations. The insulin tolerance test remains the gold standard for the diagnosis of central cortisol deficiency, but due to its risks, alternative methods with reduced diagnostic sensitivities are often used and must be interpreted with caution. ACTH deficiency may develop many years after the completion of oncological treatment alongside other pituitary hormone deficiencies. It is essential that health professionals involved in the long-term follow-up of childhood cancer survivors are aware of individuals at risk of developing HPAA dysfunction and implement appropriate monitoring and treatment.

Overweight, obesity and adiposity in survivors of childhood brain tumours: a systematic review and meta-analysis

Survivors of childhood brain tumours (SCBT) have increased cardiometabolic risks, but the determinants of these risks are unclear. This systematic review aims to compare the prevalence of overweight and obesity as well as adiposity measures between SCBT and non-cancer controls. The PubMed, EMBASE, MEDLINE, CINAHL and the Cochrane Library databases were searched. The primary outcomes were the prevalence of overweight and obesity based on body mass index. The secondary outcomes were adiposity measures including percent fat mass, waist-to-hip and waist-to-height ratios. Forty-one studies were included in the meta-analysis. The prevalence of overweight and obesity combined was similar between overall SCBT, SCBT excluding craniopharyngioma and non-cancer controls (42.6%, 95% CI 30.1-55.1 vs. 31.7%, 95% CI 20.4-43.0 vs. 40.4%, 95% CI 34.0-46.8). We also found that SCBT have higher percent fat mass (mean difference 4.1%, 95% CI 2.0-6.1), waist-to-hip ratio (mean difference 0.07, 95% CI 0.02-0.13) and waist-to-height ratio (mean difference 0.06, 95% CI 0.01-0.10) than non-cancer controls. We conclude that SCBT have similar overweight and obesity distribution but higher adiposity than non-cancer controls. More studies were needed to explore the determinants of adiposity and its contribution to cardiometabolic outcomes in SCBT.

Long-term follow-up of endocrine function among young children with newly diagnosed malignant central nervous system tumors treated with irradiation-avoiding regimens

BACKGROUND

The adverse effects of irradiation on endocrine function among patients with pediatric brain tumor are well documented. Intensive induction chemotherapy followed by marrow-ablative chemotherapy with autologous hematopoietic cell rescue (AuHCR) without central nervous system (CNS) irradiation has demonstrated efficacy in a proportion of very young children with some malignant CNS tumors. This study assessed the long-term endocrine function of young children following chemotherapy-only treatment regimens.

PROCEDURES

A retrospective chart review was performed on 99 patients under 6 years of age with malignant brain tumors newly diagnosed between May 1991 and October 2010 treated with irradiation-avoiding strategies. Thirty patients survived post-AuHCR without cranial irradiation for a mean of 8.1 years (range 3.0-22.25 years). The patient cohort included 18 males and 12 females (mean age at AuHCR of 2.5 years, range 0.8-5.1 years).

RESULTS

All 30 surviving patients had documented normal age-related thyroid function, insulin-like growth factor binding protein 3 (IGF-BP3), prolactin, testosterone, and estradiol levels. Insulin-like growth factor 1 age-related levels were abnormal in one child with normal height. Ninety-seven percent of patients had normal cortisol levels, while follicle-stimulating hormone and LH levels among females were normal in 83% and 92%, respectively, and in 100% of males. Growth charts demonstrated age-associated growth within 2 standard deviations of the mean in 67% of patients. Of 10 patients (33%) with short stature, 6 had proportional diminutions in both height and weight.

CONCLUSIONS

These findings demonstrate that the use of relatively brief, intensive chemotherapy regimens including marrow-ablative chemotherapy with AuHCR results in fewer endocrine sequelae than treatment schemes utilizing CNS irradiation.