Increased risk of bone tumors after growth hormone treatment in childhood: A population-based cohort study in France

Long-term risk of neoplastic events after childhood growth hormone treatment: a population-based cohort study in Sweden

Background

Increased risk of neoplastic events after recombinant human growth hormone (rhGH) treatment in childhood has been an ongoing concern but long-term safety data are limited.

Methods

A nationwide population-based cohort study in Sweden of patients treated with rhGH during childhood between 1985-2010, due to isolated growth hormone deficiency (GHD), small for gestational age (SGA) and idiopathic short stature (ISS). The comparison group consisted of 15 age-, sex-, and region-matched controls per patient, randomly selected from the general population. Data on neoplastic events and covariates, such as gestational age, birth weight, birth length, socioeconomic status, and height at study start, were collected through linkage with population-based registers. The cohort was followed for neoplastic events until the end of 2020.

Results

53,444 individuals (3,408 patients; 50,036 controls) were followed for up to 35 years, with a median follow-up of 19.8 years and a total of 1,050,977 person-years. Patients showed a moderately increased hazard ratio (HR) for neoplastic events overall compared to controls (HR 1.28, 95% CI: 1.12-1.46), but only significant for males (HR 1.39, 95% CI: 1.17-1.66) and not females (HR 1.15, 95% CI: 0.94-1.41). Longer treatment duration was associated with an increased HR, but no association was found between neoplastic events and mean or cumulative dose. No increased risk of malignant neoplasms was observed for the patients compared to matched controls (HR 0.91 95% CI: 0.66-1.26).

Conclusion

No association was found between rhGH treatment during childhood for GHD, SGA, or ISS and malignant neoplastic events in early to mid-adulthood. A moderate increase in overall neoplastic events was observed due to an increased number of events in male patients.

Interplay of skeletal muscle and adipose tissue: sarcopenic obesity

Sarcopenic obesity is becoming a global health concern, owing to the rising older population, causing cardiometabolic morbidity and mortality. Loss of muscle exceeding normal age-related changes has been revealed to be associated with obesity, aggravating each other through complex interactions. Physiological regeneration and proliferation of muscle tissue are achieved through harmonious processes of regulated inflammation, autophagy, muscle satellite cell proliferation, and signaling molecule function. Adipokines and myokines are signaling molecules from adipose tissue and muscle, respectively, that exert autocrine, paracrine, and endocrine effects on fat and muscle tissues. These signaling molecules interact with each other to regulate metabolic homeostasis. However, excessive adiposity creates pro-inflammatory conditions, leading to metabolic disorders and the disorganization of systemic homeostasis. Therefore, obesity impedes muscle tissue regeneration and induces the loss of muscle mass and function. Numerous studies have attempted to demonstrate the pathophysiological interaction between sarcopenia and obesity, but the interwoven matrix of the relationship between myokines and adipokines has made it difficult for researchers to understand them. This review briefly describes updated information about the crosstalk between muscle and adipose tissue.

Circulating Exosomal circRNA_0063476 Impairs Expression of Markers of Bone Growth Via the miR-518c-3p/DDX6 Axis in ISS

OBJECTIVES

Idiopathic short stature (ISS), a disorder of unknown cause, accounts for approximately 80% of the clinical diagnoses of children with short stature. Exosomal circular RNA in plasma has been implicated in various disease processes. However, the role of exosome-derived circRNA in ISS has not been elucidated yet.

METHODS

Plasma exosomes of ISS and normal children were cocultured with human chondrocytes. Microarray analysis and RT-PCR identified the differential expression of circRNA in exosomes between ISS and normal children. Hsa_circ_0063476 was upregulated or downregulated in human chondrocytes. Subsequently, overexpression rats of hsa_circ_0063476 was constructed via adenoviral vector to further validate the role of hsa_circ_0063476 on longitudinal bone growth via in vivo experiment.

RESULTS

The plasma exosome of ISS children suppressed the expression of markers of chondrocyte hypertrophy and endochondral ossification. Subsequently, upregulation of hsa_circ_0063476 in ISS exosome was identified. In vitro experiments demonstrated that chondrocyte proliferation, cell cycle and endochondral ossification were suppressed, and apoptosis was increased following hsa_circ_0063476 overexpression in human chondrocytes. Conversely, silencing hsa_circ_0063476 in human chondrocytes can show opposite outcomes. Our study further revealed hsa_circ_0063476 overexpression in vitro can enhance chondrocyte apoptosis and inhibit the expression of markers of chondrocyte proliferation and endochondral ossification via miR-518c-3p/DDX6 axis. Additionally, the rats with hsa_circ_0063476 overexpression showed a short stature phenotype.

CONCLUSIONS

The authors identified a novel pathogenesis in ISS that exosome-derived hsa_circ_0063476 retards the expression of markers of endochondral ossification and impairs longitudinal bone growth via miR-518c-3p/DDX6 axis, which may provide a unique therapeutic avenue for ISS.

Association Between Recombinant Growth Hormone Therapy and All-Cause Mortality and Cancer Risk in Childhood: Systematic Review and Meta-Analysis

OBJECTIVES

The safety of recombinant human growth hormone (rhGH) treatment in childhood and the role of rhGH therapy in promoting tumorigenesis and progression have been the subject of debate for decades. We aimed to systematically assess the relationship between rhGH therapy in children and adolescents and clinical outcomes, including all-cause mortality, cancer mortality, cancer incidence, and risk of the second neoplasm.

METHODS

Literature retrieval, study selection, and data extraction were completed independently and in duplicate. Effect-size estimates are expressed as standardized mortality ratios (SMRs), standardized incidence ratio (SIR), and relative risk (RR) with a 95% CI.

RESULTS

Data from 24 articles, involving 254,776 persons, were meta-analyzed. Overall analyses revealed the association of rhGH therapy was not statistically significant with all-cause mortality (SMR = 1.28; 95% CI: 0.58-2.84; P = 0.547; I ² = 99.2%; Tau² = 2.154) and cancer mortality (SMR = 2.59; 95% CI: 0.55-12.09; P = 0.228; I ² = 96.7%; Tau² = 2.361) and also cancer incidence (SIR = 1.54; 95% CI: 0.68-3.47; P = 0.229; I ² = 97.5%; Tau² = 2.287), yet statistical significance was observed for second neoplasm (RR = 1.77; 95% CI: 1.33-2.35; P = 0.001; I ² = 26.7%; Tau² = 0.055). Differences in the geographic region, gender, treatment duration, mean rhGH dose, overall rhGH exposure dose, and initial disease accounted for heterogeneity in the subgroup analyses.

CONCLUSION

Our findings indicate that the rhGH therapy is not related to all-cause mortality and cancer mortality and cancer incidence, yet it seems to trigger a second tumor risk. Future prospective studies are needed to confirm our findings and answer the more challenging question regarding the optimal dose of rhGH therapy in children and adolescents.

Impact of growth hormone treatment on scoliosis development and progression: analysis of 1128 patients with idiopathic short stature

OBJECTIVES

The purpose of this study was to evaluate the impact of recombinant human growth hormone (rhGH) on the development and progression of scoliosis in patients with idiopathic short stature (ISS).

METHODS

Patients with ISS who underwent rhGH treatment from 1997 to 2017 and were followed up for scoliosis screening with serial radiographic examination were included. For assessing scoliosis development, patients who did not have scoliosis at the time of rhGH treatment were included and followed up to determine whether de novo scoliosis developed during the treatment. For evaluating scoliosis progression, patients who already had scoliosis were analyzed. Univariate and multivariate Cox regression analyses of demographic and radiographic variables were performed to determine the related factors in the development and progression of scoliosis.

RESULTS

For assessing scoliosis development, 1093 patients were included. The average duration of rhGH treatment was about 2 years. De novo scoliosis developed in 32 patients (3.7%). The analysis revealed that sex (p=0.016) and chronological age (p=0.048) were statistically significant factors associated with scoliosis development. However, no relationship was observed between scoliosis development and rhGH treatment types or duration. Among 67 patients who already had scoliosis at the time of rhGH treatment, 11 (16.4%) showed scoliosis progression. However, the rhGH types and duration also did not affect scoliosis progression.

CONCLUSIONS

De novo scoliosis developed in 3.7% and scoliosis progressed in 16.4% of the patients during rhGH treatment. However, scoliosis development or progression was not affected by the types or duration of rhGH treatment in patients with ISS.

GH and IGF System: The Regulatory Role of miRNAs and lncRNAs in Cancer

Growth hormone (GH) and the insulin-like growth factor (IGF) system are involved in many biological processes and have growth-promoting actions regulating cell proliferation, differentiation, apoptosis and angiogenesis. A recent chapter in epigenetics is represented by microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) which regulate gene expression. Dysregulated miRNAs and lncRNAs have been associated with several diseases including cancer. Herein we report the most recent findings concerning miRNAs and lncRNAs regulating GH and the IGF system in the context of pituitary adenomas, osteosarcoma and colorectal cancer, shedding light on new possible therapeutic targets. Pituitary adenomas are increasingly common intracranial tumors and somatotroph adenomas determine supra-physiological GH secretion and cause acromegaly. Osteosarcoma is the most frequent bone tumor in children and adolescents and was reported in adults who were treated with GH in childhood. Colorectal cancer is the third cancer in the world and has a higher prevalence in acromegalic patients.

Safety of Pediatric rhGH Therapy: An Overview and the Need for Long-Term Surveillance

Growth hormone (GH) therapy dates back to 1958 and, though has shown an excellent safety profile in the short-term, has never ceased to raise concern about potential long-term side effects. In the last decade, a number of observational studies in different cohorts of young adult patients treated with GH during childhood have yielded conflicting results. The attention has mainly focused on three major potential risks associated with GH therapy: cancer, cardio and cerebrovascular diseases and diabetes. This review intends to provide a detailed overview of the main studies reporting long-term safety in subjects treated with rhGH therapy during childhood, highlighting the evidence for or against the risk of cancer, cardio and cerebrovascular diseases and diabetes.

Role of the GH-IGF1 system in progression of cancer

Emerging evidence links the growth hormone (GH)-insulin-like growth factor-1 (IGF1) endocrine axis to cancer development. While this putative correlation is of major translational relevance, most clinical and epidemiological reports to date found no causal linkage between GH therapy and enhanced cancer risk. Thus, it is generally agreed that GH therapy constitutes a safe pharmacological intervention. The present review focuses on a number of issues in the area of GH-IGF1 action in cancer development. Emphasis is given to the idea that GH and IGF1 do not conform to the definition of oncogenic factors. Specifically, these hormones, even at high pharmacological doses, are unable to induce malignant transformation. However, the GH-IGF1 axis is capable of 'pushing' already transformed cells through the various phases of the cell cycle. Viral and cellular oncogenes require an intact IGF1 signaling pathway in order to elicit transformation; in other words, oncogenic agents adopt the IGF1 pathway. This universal mechanism of action of oncogenes has broad implications in oncology. Our review provides an in-depth analysis of the interplay between the GH-IGF1 axis and cancer genes, including tumor suppressors p53 and BRCA1. Finally, the safety of GH therapy in both children and adults needs further long-term follow-up studies.

The Challenge of Defining and Investigating the Causes of Idiopathic Short Stature and Finding an Effective Therapy

Idiopathic short stature (ISS) comprises a wide range of conditions associated with short stature that elude the conventional diagnostic work-up and are often caused by still largely unknown genetic variants. In the last decade, the improvement of diagnostic techniques has led to the discovery of causal mutations in genes involved in the function of the growth hormone (GH)/insulin-like growth factor-I (IGF-I) axis as well as in growth plate physiology. However, many cases of ISS remain idiopathic. In the future, the more frequent identification of the underlying causes will allow a better stratification of subjects and offer a tailored management. GH therapy has been proposed and approved in some countries for the treatment of children with ISS. To improve the efficacy of GH therapy, trials with GH combined with GnRH agonists, aromatase inhibitors, and even IGF-I have been conducted. This review aims to revise the current definition of ISS and discuss the management of children with ISS on the basis of the most recent evidence.

The effects of growth hormone on therapy resistance in cancer

Pituitary derived and peripherally produced growth hormone (GH) is a crucial mediator of longitudinal growth, organ development, metabolic regulation with tissue specific, sex specific, and age-dependent effects. GH and its cognate receptor (GHR) are expressed in several forms of cancer and have been validated as an anti-cancer target through a large body of in vitro, in vivo and epidemiological analyses. However, the underlying molecular mechanisms of GH action in cancer prognosis and therapeutic response had been sparse until recently. This review assimilates the critical details of GH-GHR mediated therapy resistance across different cancer types, distilling the therapeutic implications based on our current understanding of these effects.

Electrospun Polyvinylidene Fluoride-Based Fibrous Scaffolds with Piezoelectric Characteristics for Bone and Neural Tissue Engineering

Polyvinylidene fluoride (PVDF) and polyvinylidene fluoride-trifluoroethylene (P(VDF-TrFE) with excellent piezoelectricity and good biocompatibility are attractive materials for making functional scaffolds for bone and neural tissue engineering applications. Electrospun PVDF and P(VDF-TrFE) scaffolds can produce electrical charges during mechanical deformation, which can provide necessary stimulation for repairing bone defects and damaged nerve cells. As such, these fibrous mats promote the adhesion, proliferation and differentiation of bone and neural cells on their surfaces. Furthermore, aligned PVDF and P(VDF-TrFE) fibrous mats can enhance neurite growth along the fiber orientation direction. These beneficial effects derive from the formation of electroactive, polar β-phase having piezoelectric properties. Polar β-phase can be induced in the PVDF fibers as a result of the polymer jet stretching and electrical poling during electrospinning. Moreover, the incorporation of TrFE monomer into PVDF can stabilize the β-phase without mechanical stretching or electrical poling. The main drawbacks of electrospinning process for making piezoelectric PVDF-based scaffolds are their small pore sizes and the use of highly toxic organic solvents. The small pore sizes prevent the infiltration of bone and neuronal cells into the scaffolds, leading to the formation of a single cell layer on the scaffold surfaces. Accordingly, modified electrospinning methods such as melt-electrospinning and near-field electrospinning have been explored by the researchers to tackle this issue. This article reviews recent development strategies, achievements and major challenges of electrospun PVDF and P(VDF-TrFE) scaffolds for tissue engineering applications.

Risk of cancer in patients treated with recombinant human growth hormone in childhood

Recombinant human growth hormone (GH) has been in use for over 30 years, and its indications have gradually expanded from the classical replacement therapy in GH deficiency (GHD) to pharmacological therapy in patients with normal GH secretion. The insulin-like growth factor-I (IGF-I ) is closely GH dependent and is the effector of GH biological actions in peripheral tissues. Since IGF-I has potent mitogenic and antiapoptotic effects, the use of GH, especially outside GHD, has raised safety concern regarding cancer risk. The results of experimental, epidemiological and observational studies are not univocal and a number of biases and confounders affect the interpretation of data. The aim of this review is to critically review the data linking GH therapy during childhood with cancer risk, highlighting strengths and weaknesses of the available evidence.

Increased risk of bone tumors after growth hormone treatment in childhood: A population-based cohort study in France

The association between growth hormone (GH) treatment and cancer risk has not been thoroughly evaluated and there are questions about any increased risk of bone tumors. We examined cancer risk and especially bone tumor risk in a population-based cohort study of 6874 patients treated with recombinant GH in France for isolated GH deficiency, short stature associated with low birth weight or length or idiopathic short stature. Adult mortality and morbidity data obtained from national databases and from questionnaires. Case ascertainment completeness was estimated with capture-recapture methods. Standardized mortality and incidence ratios were calculated using national reference data. 111 875 person-years of observation were analyzed and patients were followed for an average of 17.4 ± 5.3 years to a mean age of 28.4 ± 6.2 years. For cancer overall, mortality and incidence were not different from expected figures. Five patients developed bone tumors (chondrosarcoma, 1, Ewing sarcoma, 1, osteosarcoma, 3) of whom 3 died (Ewing sarcoma, 1, osteosarcoma, 2), whereas only 1.4 case and 0.6 deaths were expected: standardized mortality ratio, 5.0 and standardized incidence ratio from 3.5 to 3.8 accounting or not accounting for missed cases. Most patients received conventional doses of GH, although one patient with osteosarcoma had received high dose GH (60 μg/kg/d). This study confirms an increased risk of bone tumors but not overall cancer risk in subjects treated with GH in childhood for isolated GH deficiency or childhood short stature. Further work is needed to elucidate the mechanisms involved.