The limited screening value of insulin-like growth factor-I as a marker for alterations in body composition in very long-term adult survivors of childhood cancer

Impact of Childhood Cancer on Growth

Along with improvements in cancer treatment over time, the number of childhood cancer survivors has been growing. Survivors are at risk for serious medical complications, and growth impairment is among the most common. There are multiple factors that may cause impaired growth among survivors. In this article, we review the impact of cancer on growth in children and adolescents. We first provide an overview of growth disturbance among childhood cancer patients and survivors due to nonhormonal causes, including a recent understanding of the effect of targeted cancer therapies (eg, tyrosine kinase inhibitors and immune checkpoint inhibitors) on growth. Then we describe the hormonal causes of growth impairment among survivors, focusing on growth hormone deficiency, including the prevalence, risk factors, and treatment. Lastly, we briefly summarize overgrowth and tall stature in childhood cancer. It is critical to assess the linear growth of children and adolescents, especially in cancer survivors who are at risk for growth disturbance, since growth is an important measure of their health.

Expert Opinion on the Management of Growth Hormone Deficiency in Brain Tumor Survivors: Results From an Italian Survey

BACKGROUND

Growth hormone deficiency (GHD) is the first and most common endocrine complication in pediatric brain tumor survivors (BTS). GHD can occur due to the presence of the tumor itself, surgery, or cranial radiotherapy (CRT).

AIMS

This study aimed to evaluate management and adherence to current guidelines of the Italian centers engaged in the diagnosis and follow-up of GHD patients with BTS.

METHODS

A multidisciplinary scientific board of pediatric endocrinologists, oncologists and radiologists with neuroimaging expertise discussed and reviewed the main issues relating to the management of GHD in pediatric BTS and developed a survey. The survey included questions relating to organizational aspects, risk factors, diagnosis, definition of stable disease, and treatment. The online survey was sent to an expanded panel of specialists dedicated to the care of pediatric BTS, distributed among the three specialty areas and throughout the country (23 Italian cities and 37 Centers).

RESULTS

The online questionnaire was completed by 86.5% (32 out of 37) of the Centers involved. Most had experience in treating these patients, reporting that they follow more than 50 BTS patients per year. Responses were analyzed descriptively and aggregated by physician specialty. Overall, the results of the survey showed some important controversies in real life adherence to the current guidelines, with discrepancies between endocrinologists and oncologists in the definition of risk factors, diagnostic work-up, decision-making processes and safety. Furthermore, there was no agreement on the neuroimaging definition of stable oncological disease and how to manage growth hormone therapy in patients with residual tumor and GHD.

CONCLUSIONS

The results of the first Italian national survey on the management of GHD in BTS highlighted the difference in management on some important issues. The time to start and stop rhGH treatment represent areas of major uncertainty. The definition of stable disease remains critical and represents a gap in knowledge that must be addressed within the international guidelines in order to increase height and to improve metabolic and quality of life outcomes in cancer survivors with GHD.

Hypothalamic-Pituitary and Growth Disorders in Survivors of Childhood Cancer: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

To formulate clinical practice guidelines for the endocrine treatment of hypothalamic-pituitary and growth disorders in survivors of childhood cancer.

PARTICIPANTS

An Endocrine Society-appointed guideline writing committee of six medical experts and a methodologist.

CONCLUSIONS

Due to remarkable improvements in childhood cancer treatment and supportive care during the past several decades, 5-year survival rates for childhood cancer currently are >80%. However, by virtue of their disease and its treatments, childhood cancer survivors are at increased risk for a wide range of serious health conditions, including disorders of the endocrine system. Recent data indicate that 40% to 50% of survivors will develop an endocrine disorder during their lifetime. Risk factors for endocrine complications include both host (e.g., age, sex) and treatment factors (e.g., radiation). Radiation exposure to key endocrine organs (e.g., hypothalamus, pituitary, thyroid, and gonads) places cancer survivors at the highest risk of developing an endocrine abnormality over time; these endocrinopathies can develop decades following cancer treatment, underscoring the importance of lifelong surveillance. The following guideline addresses the diagnosis and treatment of hypothalamic-pituitary and growth disorders commonly encountered in childhood cancer survivors.

Long-Term Effect of Cranial Radiotherapy on Pituitary-Hypothalamus Area in Childhood Acute Lymphoblastic Leukemia Survivors

Survival rates of childhood cancer have improved markedly, and today more than 80 % of those diagnosed with a pediatric malignancy will become 5-year survivors. Nevertheless, survivors exposed to cranial radiotherapy (CRT) are at particularly high risk for long-term morbidity, such as endocrine insufficiencies, metabolic complications, and cardiovascular morbidity. Deficiencies of one or more anterior pituitary hormones have been described following therapeutic CRT for primary brain tumors, nasopharyngeal tumors, and following prophylactic CRT for childhood acute lymphoblastic leukemia (ALL). Studies have consistently shown a strong correlation between the total radiation dose and the development of pituitary deficits. Further, age at treatment and also time since treatment has strong implications on pituitary hormone deficiencies. There is evidence that the hypothalamus is more radiosensitive than the pituitary and is damaged by lower doses of CRT. With doses of CRT <50 Gy, the primary site of radiation damage is the hypothalamus and this usually causes isolated GH deficiency (GHD). Higher doses (>50 Gy) may produce direct anterior pituitary damage, which contributes to multiple pituitary deficiencies. The large group of ALL survivors treated with CRT in the 70–80-ties has now reached adulthood, and these survivors were treated mainly with 24 Gy, and the vast majority of these patients suffer from GHD. Further, after long-term follow-up, insufficiencies in prolactin (PRL) and thyroid stimulating hormone (TSH) have also been reported and a proportion of these patients were also adrenocoticotrophic hormone (ACTH) deficient. CRT to the hypothalamus causes neuroendocrine dysfunction, which means that the choice of GH test is crucial for the diagnosis of GHD.

Endocrinopathies in survivors of childhood neoplasia

Advancements in cancer treatments have increased the number of survivors of childhood cancers. Endocrinopathies are common complications following cancer therapy and may occur decades later. The objective of the current review is to address the main endocrine abnormalities detected in childhood cancer survivors including disorders of the hypothalamic-pituitary axis, thyroid, puberty, gonads, bone, body composition, and glucose metabolism.

Final height and IGF1 in adult survivors of Wilms tumour

OBJECTIVE

One-sided nephrectomy is followed by increased levels of IGF1, associated with linear growth during childhood. The aim was to evaluate final height and IGF1 levels in nephrectomized Wilms tumour survivors when compared with healthy Dutch references and survivors of other cancer types.

DESIGN

Cross-sectional retrospective study.

METHODS

Data of 575 adult childhood cancer survivors were analysed. median follow-up time was 17.8 (range 5.048.8) years. Analysis of (co)variance was performed to evaluate differences between subgroups: nephrectomized Wilms survivors treated with or without abdominal irradiation (n=41 and n=36) and survivors of other cancer types treated with or without irradiation involving the cranium, abdomen or total body (n=149 and n=349). Main outcome measures were IGF1 and height, expressed as SDS.

RESULTS

After adjustment for age at diagnosis, former corticosteroid treatment and renal impairment, height SDS in non-irradiated nephrectomized Wilms survivors was significantly higher than that in non-irradiated survivors of other cancer types (estimated mean SDS -0.09 vs -0.49, P=0.044), abdominal irradiated survivors (SDS -0.70, P=0.015) and other irradiated survivors (SDS -1.47, P<0.001). Non-irradiated nephrectomized Wilms tumour survivors had significantly higher IGF1 SDS than other irradiated survivors (estimated mean SDS -0.05 vs -1.36, P<0.001 and 0.11 vs 1.37, P<0.001), while there was no significant difference with the other two subgroups.

CONCLUSIONS

Adult survivors of Wilms tumour showed better attainment of final height and relatively higher IGF1 levels than those of other cancer types who had significantly shorter stature and lower IGF1 levels than Dutch references.

Blunted response to a growth hormone stimulation test is associated with unfavorable cardiovascular risk factor profile in childhood cancer survivors

BACKGROUND

Childhood cancer survivors (CCS) are at risk for growth hormone (GH) deficiency. CCS are also at increased risk for early mortality from cardiovascular (CV) disease, but the association between GH levels and CV risk remains poorly understood. The goal of this study was to examine the cross-sectional association between stimulated GH levels and CV risk factors in CCS younger than 18 years.

PROCEDURE

A total of 276 CCS (147 males, 14.4 ± 2.6 years) ≥5 years after cancer diagnosis, and 208 sibling controls (112 males, 13.6 ± 2.4 years) participated in this cross-sectional study, which included anthropometry, body composition, and metabolic studies. Blunted response (BR) was defined as peak GH level <7 µg/L after clonidine and arginine. Insulin sensitivity (M(lbm) ) was measured by euglycemic hyperinsulinemic clamp. Statistical analyses used linear and logistic regression accounting for sibling clustering, adjusted for age, sex, Tanner stage, and adiposity.

RESULTS

Thirty-four (12%) CCS showed BR to GH stimulation. BR CCS were shorter and had a lower IGF-1 than controls; only 6 of 34 received cranial radiation therapy. CCS with normal stimulated GH response were similar to controls for CV risk factors. Conversely, BR CCS had greater adiposity, higher lipids, and lower M(lbm) than controls. Differences in lipids and M(lbm) between BR CCS and controls remained significant after adjustment for BMI or visceral fat.

CONCLUSIONS

BR to GH stimulation is prevalent in CCS youth and is associated with an unfavorable CV risk factor profile. Further studies are needed to establish the mechanisms of these associations.

Abdominal radiotherapy: a major determinant of metabolic syndrome in nephroblastoma and neuroblastoma survivors

BACKGROUND

Reports on metabolic syndrome in nephroblastoma and neuroblastoma survivors are scarce. Aim was to evaluate the occurrence of and the contribution of treatment regimens to the metabolic syndrome.

PATIENTS AND METHODS

In this prospective study 164 subjects participated (67 adult long-term nephroblastoma survivors (28 females), 36 adult long-term neuroblastoma survivors (21 females) and 61 control subjects (28 females)). Controls were recruited cross-sectionally. Waist and hip circumference as well as blood pressure were measured. Body composition and abdominal fat were assessed by dual energy X-ray absorptiometry (DXA-scan). Laboratory measurements included fasting triglyceride, high density lipoprotein-cholesterol (HDL-C), glucose, insulin, low-density lipoprotein-cholesterol (LDL-C) and free fatty acids (FFA) levels.

RESULTS

Median age at follow-up was 30 (range 19-51) years in survivors and 32 (range 18-62) years in controls. Median follow-up time in survivors was 26 (6-49) years. Nephroblastoma (OR = 5.2, P<0.0001) and neuroblastoma (OR 6.5, P<0.001) survivors had more components of the metabolic syndrome than controls. Survivors treated with abdominal irradiation had higher blood pressure, triglycerides, LDL-C, FFA and lower waist circumference. The latter can not be regarded as a reliable factor in these survivors as radiation affects the waist circumference. When total fat percentage was used as a surrogate marker of adiposity the metabolic syndrome was three times more frequent in abdominally irradiated survivors (27.5%) than in non-irradiated survivors (9.1%, P = 0.018).

CONCLUSIONS

Nephroblastoma and neuroblastoma survivors are at increased risk for developing components of metabolic syndrome, especially after abdominal irradiation. We emphasize that survivors treated with abdominal irradiation need alternative adiposity measurements for assessment of metabolic syndrome.