International consensus on mitotane treatment in pediatric patients with adrenal cortical tumors: indications, therapy, and management of adverse effects

OBJECTIVE

Mitotane is an important cornerstone in the treatment of pediatric adrenal cortical tumors (pACC), but experience with the drug in the pediatric age group is still limited and current practice is not guided by robust evidence. Therefore, we have compiled international consensus statements from pACC experts on mitotane indications, therapy, and management of adverse effects.

METHODS

A Delphi method with 3 rounds of questionnaires within the pACC expert consortium of the international network groups European Network for the Study of Adrenal Tumors pediatric working group (ENSAT-PACT) and International Consortium of pediatric adrenocortical tumors (ICPACT) was used to create 21 final consensus statements.

RESULTS

We divided the statements into 4 groups: environment, indications, therapy, and adverse effects. We reached a clear consensus for mitotane treatment for advanced pACC with stages III and IV and with incomplete resection/tumor spillage. For stage II patients, mitotane is not generally indicated. The timing of initiating mitotane therapy depends on the clinical condition of the patient and the setting of the planned therapy. We recommend a starting dose of 50 mg/kg/d (1500 mg/m²/d) which can be increased up to 4000 mg/m2/d. Blood levels should range between 14 and 20 mg/L. Duration of mitotane treatment depends on the clinical risk profile and tolerability. Mitotane treatment causes adrenal insufficiency in virtually all patients requiring glucocorticoid replacement shortly after beginning. As the spectrum of adverse effects of mitotane is wide-ranging and can be life-threatening, frequent clinical and neurological examinations (every 2-4 weeks), along with evaluation and assessment of laboratory values, are required.

CONCLUSIONS

The Delphi method enabled us to propose an expert consensus statement, which may guide clinicians, further adapted by local norms and the individual patient setting. In order to generate evidence, well-constructed studies should be the focus of future efforts.

DNA methylation is a comprehensive marker for pediatric adrenocortical tumors

Children diagnosed with pediatric adrenocortical tumors (pACT) have variable outcomes, and, to date, the disease lacks robust prognostic biomarkers. The prognostic potential of tumor methylation has been demonstrated in several cancers. We aimed to evaluate the pACT methylation profile and its association with disease presentation and survival. In this cross-sectional study, we accessed the DNA methylation (MethylationEPIC Array, Illumina) of 57 primary pACT from Southeastern Brazil and the respective patients' clinicopathological features. We also applied our analysis in an independent 48 pACT methylation dataset. Unsupervised learning whole-methylome analysis showed two groups with distinct methylation signatures: pACT-1 and pACT-2. Compared to pACT-2, pACT-1 tumors were enriched with higher methylation in CpG islands, mainly in gene promoter regions. The topmost hypermethylated gene in these samples was shown to be underexpressed. Patients in the pACT-1 group were older at diagnosis and were more likely to have carcinomas and nonlocalized/advanced and recurrent/metastatic disease. Univariate and bivariate regressions showed that pACT-1 methylation signature confers superior hazard ratio of disease progression and death than known prognostic features. The methylation groups had similar frequencies of germline mutations in the TP53 gene, including the regionally frequent p.R337H. Our analysis replication validated our findings and reproduced those recently described in pACT. We demonstrated the existence of different tumor methylation signatures associated with pACT presentation and clinical evolution, even in the context of germline TP53 mutations. Our data support tumor methylation profiling as a robust and independent prognostic biomarker for pACT and suggest a list of candidate genes for further validation.

SAT-LB36 Distinct Vitamin D Receptor DNA Methylation Profiles Are Associated With the Outcome of Pediatric Patients With Adrenocortical Tumors

Pediatric adrenocortical tumors (pACT) are rare, display complex genomic background and lack robust prognostic markers. Very recently, distinct genomic methylation profiles of pACT were associated with prognosis. The vitamin D receptor (VDR) was shown to be underexpressed in ACT, especially in carcinomas (ACC). In adult ACC, VDR inactivation by methylation was demonstrated. On the other hand, VDR activation was shown to inhibit ACC proliferation in vitro and in vivo.

Aim: To evaluate VDR DNA methylation profile and its clinical and prognostic significance in pediatric ACT.

Methods: Genomic DNA methylation from 57 pACTs [40 girls; median age: 2.1 (0.2-16.4) years] was assessed using Infininium Methylation EPIC BeadChip Array. Unsupervised hierarchical clustering analysis (Ward method, R Stats Package) was performed considering the M-values of the 49 probes targeting the whole extension of VDR gene contained in the array. Clinical, histopathological and molecular features, as well as pACT VDR mRNA levels (qPCR) and nuclear immunoreactivity (IHC) were used for association analysis.

Results: Hierarchical clustering identified three clusters of pACT. Methylated VDR-targeted probes (M-values different from 0; n=37) composed the VDR methylation profile, which differed significantly between the clusters [M-values: C1=1.77 (1.1-1.9) (low), C2=2.15 (1.7-2.7) (intermediate), and C3=2.65 (2.2-3.1) (high); p<0.0001]. The C1 cluster comprised a set of patients with favorable outcome (n=18), who were younger (p=0.035), did not present metastasis at diagnosis (IPACTR stage IV) or after surgery, nor were diagnosed with carcinomas (Wieneke criteria >=4), were not carriers of somatic Beta-catenin activating mutations, or died. Although cluster C2 patients (n=21) presented intermediary disease features, only 2 patients died and the overall outcome was positive. Instead, the C3 cluster concentrated patients (n=18) with non-localized/metastatic disease (IPACTR stages I/II vs. III/IV; p=0.004), post-surgical metastasis/recurrence (p=0.009), and patients who needed adjuvant chemotherapy (p=0.005). Moreover, C3 patients had lower overall and disease-free survival rates (log-rank: p=0.001 and p=0.014, respectively). VDR methylation was not associated with sex, clinical presentation, P53 mutations, nor with tumor VDR mRNA expression or nuclear immunoreactivity.

Conclusions: Three VDR methylation profiles were associated with distinct pACT clinical features and outcome. High VDR methylation was associated with worst outcome. Fully functioning VDR may play a beneficial role against pediatric adrenocortical tumorigenesis. This finding highlights the potential of targeting VDR as an adjuvant therapeutic target.

Outcomes of Patients with Central Precocious Puberty Due to Loss-of-Function Mutations in the MKRN3 Gene after Treatment with Gonadotropin-Releasing Hormone Analog

INTRODUCTION

Loss-of-function mutation of MKRN3 represents the most frequent genetic cause of familial central precocious puberty (CPP). The outcomes of gonadotropin-releasing hormone analog (GnRHa) treatment in CPP patients with MKRN3 defects are unknown.

OBJECTIVE

To describe the clinical and hormonal features of patients with CPP with or without MKRN3 mutations after GnRHa treatment. Anthropometric, metabolic and reproductive parameters were evaluated.

PATIENTS AND METHODS

Twenty-nine female patients with CPP due to loss-of-function mutations in the MKRN3 and 43 female patients with idiopathic CPP were included. Their medical records were retrospectively evaluated for clinical, laboratory, and imaging study, before, during, and after GnRHa treatment. All patients with idiopathic CPP and 11 patients with CPP due to MKRN3 defects reached final height (FH).

RESULTS

At the diagnosis, there were no significant differences between clinical and laboratory features of patients with CPP with or without MKRN3 mutations. A high prevalence of overweight and obesity was observed in patients with CPP with or without MKRN3 mutations (47.3 and 50%, respectively), followed by a significant reduction after GnRHa treatment. No significant differences in the values of mean FH and target height were found between the 2 CPP groups after GnRHa treatment. Menarche occurred at the expected age in patients with or without CPP due to MKRN3 mutations (11.5 ± 1.3 and 12 ± 0.6 years, respectively). The prevalence of polycystic ovarian syndrome was 9.1% in patients with CPP due to MKRN3 mutations and 5.9% in those with idiopathic CPP.

CONCLUSION

Anthropometric, metabolic, and reproductive outcomes after GnRHa treatment were comparable in CPP patients, with or without MKRN3 mutations, suggesting the absence of deleterious effects of MKRN3 defects in young female adults' life.

Low expression of HLA-DRA, HLA-DPA1, and HLA-DPB1 is associated with poor prognosis in pediatric adrenocortical tumors (ACT)

BACKGROUND

Low expression of HLA class II antigens has been associated with more aggressive disease in several human malignancies including adult adrenocortical tumors (ACT), but their clinical relevance in pediatric ACT needs to be investigated.

PROCEDURE

This study analyzed the expression profile of three class II histocompatibility genes (HLA-DRA, HLA-DPA1, and HLA-DPB1) in 58 consecutive pediatric ACT (13 adenomas and 45 carcinomas) by quantitative real time PCR and their association with clinical and biological features. HLA-DPA1 protein level was determined by immunohistochemistry.

RESULTS

A significant association (P < 0.01) was observed between lower expression levels of the three genes analyzed and poor prognostic factors such as age ≥ 4 years, tumor size ≥ 200 cm(3), tumor weight ≥ 100 g, and metastatic disease; the presence of an unfavorable event and death. Underexpression of the HLA-DRA, HLA-DPA1, and HLA-DPB1 genes were associated with lower 5-year event-free survival (EFS) (P = 0.017, P < 0.001, and P = 0.017, respectively). Cox multivariate analysis showed that HLA-DPA1 was an independent prognostic factor (P = 0.029) when analyzed in association with stage IV, age and tumor size. Significantly lower EFS was also observed in patients with negative/weak immunostaining for HLA-DPA1 (P = 0.002). Similar results were observed when only patients classified as having carcinomas were analyzed.

CONCLUSION

Our results suggest that lower expression of HLA-DRA, HLA-DPA1, and HLA-DPB1 genes may contribute to more aggressive disease in pediatric ACT. HLA-DPA1 immunostaining may represent potential aggressiveness marker in this tumor.

Genetic predictors of long-term response to growth hormone (GH) therapy in children with GH deficiency and Turner syndrome: the influence of a SOCS2 polymorphism

BACKGROUND

There is great interindividual variability in the response to GH therapy. Ascertaining genetic factors can improve the accuracy of growth response predictions. Suppressor of cytokine signaling (SOCS)-2 is an intracellular negative regulator of GH receptor (GHR) signaling.

OBJECTIVE

The objective of the study was to assess the influence of a SOCS2 polymorphism (rs3782415) and its interactive effect with GHR exon 3 and -202 A/C IGFBP3 (rs2854744) polymorphisms on adult height of patients treated with recombinant human GH (rhGH).

DESIGN AND PATIENTS

Genotypes were correlated with adult height data of 65 Turner syndrome (TS) and 47 GH deficiency (GHD) patients treated with rhGH, by multiple linear regressions. Generalized multifactor dimensionality reduction was used to evaluate gene-gene interactions.

RESULTS

Baseline clinical data were indistinguishable among patients with different genotypes. Adult height SD scores of patients with at least one SOCS2 single-nucleotide polymorphism rs3782415-C were 0.7 higher than those homozygous for the T allele (P < .001). SOCS2 (P = .003), GHR-exon 3 (P= .016) and -202 A/C IGFBP3 (P = .013) polymorphisms, together with clinical factors accounted for 58% of the variability in adult height and 82% of the total height SD score gain. Patients harboring any two negative genotypes in these three different loci (homozygosity for SOCS2 T allele; the GHR exon 3 full-length allele and/or the -202C-IGFBP3 allele) were more likely to achieve an adult height at the lower quartile (odds ratio of 13.3; 95% confidence interval of 3.2-54.2, P = .0001).

CONCLUSION

The SOCS2 polymorphism (rs3782415) has an influence on the adult height of children with TS and GHD after long-term rhGH therapy. Polymorphisms located in GHR, IGFBP3, and SOCS2 loci have an influence on the growth outcomes of TS and GHD patients treated with rhGH. The use of these genetic markers could identify among rhGH-treated patients those who are genetically predisposed to have less favorable outcomes.

Sonic hedgehog signaling is active in human adrenal cortex development and deregulated in adrenocortical tumors

BACKGROUND

The sonic hedgehog (SHH) pathway plays a key role in rodent adrenal cortex development and is involved in tumorigenesis in several human tissues, but data in human adrenal glands are limited.

OBJECTIVES

The objectives of the study were to analyze the involvement of the SHH pathway in human adrenal development and tumorigenesis and the effects of SHH inhibition on an adrenocortical tumor (ACT) cell line.

PATIENTS AND METHODS

Expression of SHH pathway components was evaluated by immunohistochemistry in 51 normal adrenals (33 fetal) and 34 ACTs (23 pediatric) and by quantitative PCR in 81 ACTs (61 pediatric) and 19 controls (10 pediatric). The effects of SHH pathway inhibition on gene expression and cell viability in the NCI-H295A adrenocortical tumor cell line after cyclopamine treatment were analyzed.

RESULTS

SHH pathway proteins were present in fetal and postnatal normal adrenals and showed distinct patterns of spatiotemporal expression throughout development. Adult adrenocortical carcinomas presented with higher expression of PTCH1, SMO, GLI3, and SUFU compared with normal adult adrenal cortices. Conversely, pediatric ACTs showed lower mRNA expression of SHH, PTCH1, SMO, GLI1, and GLI3 compared with normal pediatric adrenal cortices. In vitro treatment with cyclopamine resulted in decreased GLI3, SFRP1, and CTNNB1 mRNA expression and β-catenin staining as well as decreased cell viability.

CONCLUSIONS

The SHH pathway is active in human fetal and postnatal adrenals, up-regulated in adult adrenocortical carcinomas, and down-regulated in pediatric ACTs. SHH pathway antagonism impaired cell viability. The SHH pathway is deregulated in ACTs and might provide a new target therapy to be explored.

PP002. Study of polymorphisms of the adiponectin gene in women with gestational hypertension and preeclampsia

INTRODUCTION

Adiponectin is involved in energy homeostasis by regulating glucose and lipid metabolism. Additionally, it presents anti-inflammatory and anti-atherosclerotic functions. Polymorphisms in adiponectin gene (ADIPOQ) can modulate the concentrations of adiponectin. The influence of these polymorphisms on the development of gestational hypertension (GH) and preeclampsia (PE) is unknown.

OBJECTIVES

The aim of this work was to examine the influence of polymorphisms in the gene ADIPOQ on the development of gestational hypertension and preeclampsia.

METHODS

PATIENTS AND METHODS

We studied 401 pregnant women: 161 healthy pregnant (HP), 113 pregnant with gestational hypertension (GH) and 127 pregnant with preeclampsia (PE). Polymorphisms ADIPOQ -11391G>A (rs17300539), -11377C>G (rs266729), 45T>G (rs2241766) and 276G>T (rs1501299) were genotyped by allelic discrimination by PCR in real time. Haplotypes were inferred using the PHASE 2.1 program.

RESULTS

There were no statistically significant differences in allele and genotype frequencies of the polymorphisms studied. In the analysis of haplotypes, we observed small differences in haplotype frequencies between groups, however, none of these differences was statistically significant (P>0.05).

CONCLUSION

We found no association between the genotypic and allelic variants of the ADIPOQ gene polymorphisms with the development of gestational hypertension and preeclampsia.

The interactive effect of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms on rhGH responsiveness and treatment outcomes in patients with Turner syndrome

CONTEXT

There is great interindividual variability in the response to recombinant human (rh) GH therapy in patients with Turner syndrome (TS). Ascertaining genetic factors can improve the accuracy of growth response predictions.

OBJECTIVE

The objective of the study was to assess the individual and combined influence of GHR-exon 3 and -202 A/C IGFBP3 polymorphisms on the short- and long-term outcomes of rhGH therapy in patients with TS.

DESIGN AND PATIENTS

GHR-exon 3 and -202 A/C IGFBP3 genotyping (rs2854744) was correlated with height data of 112 patients with TS who remained prepubertal during the first year of rhGH therapy and 65 patients who reached adult height after 5 ± 2.5 yr of rhGH treatment.

MAIN OUTCOME MEASURES

First-year growth velocity and adult height were measured.

RESULTS

Patients carrying at least one GHR-d3 or -202 A-IGFBP3 allele presented higher mean first-year growth velocity and achieved taller adult heights than those homozygous for GHR-fl or -202 C-IGFBP3 alleles, respectively. The combined analysis of GHR-exon 3 and -202 A/C IGFBP3 genotypes showed a clear nonadditive epistatic influence on adult height of patients with TS treated with rhGH (GHR-exon 3 alone, R² = 0.27; -202 A/C IGFBP3, R² = 0.24; the combined genotypes, R² = 0.37 at multiple linear regression). Together with clinical factors, these genotypes accounted for 61% of the variability in adult height of patients with TS after rhGH therapy.

CONCLUSION

Homozygosity for the GHR-exon3 full-length allele and/or the -202C-IGFBP3 allele are associated with less favorable short- and long-term growth outcomes after rhGH treatment in patients with TS.

Bone mineral density and body composition in girls with idiopathic central precocious puberty before and after treatment with a gonadotropin-releasing hormone agonist

OBJECTIVES

Idiopathic central precocious puberty and its postponement with a (gonadotropin-releasing hormone) GnRH agonist are complex conditions, the final effects of which on bone mass are difficult to define. We evaluated bone mass, body composition, and bone remodeling in two groups of girls with idiopathic central precocious puberty, namely one group that was assessed at diagnosis and a second group that was assessed three years after GnRH agonist treatment.

METHODS

The precocious puberty diagnosis and precocious puberty treatment groups consisted of 12 girls matched for age and weight to corresponding control groups of 12 (CD) and 14 (CT) girls, respectively. Bone mineral density and body composition were assessed by dual X-ray absorptiometry. Lumbar spine bone mineral density was estimated after correction for bone age and the mathematical calculation of volumetric bone mineral density. CONEP: CAAE-0311.0.004.000-06.

RESULTS

Lumbar spine bone mineral density was slightly increased in individuals diagnosed with precocious puberty compared with controls; however, after correction for bone age, this tendency disappeared (CD = -0.74 + 0.9 vs. precocious puberty diagnosis = -1.73 + 1.2). The bone mineral density values of girls in the precocious puberty treatment group did not differ from those observed in the CT group.

CONCLUSION

There is an increase in bone mineral density in girls diagnosed with idiopathic central precocious puberty. Our data indicate that the increase in bone mineral density in girls with idiopathic central precocious puberty is insufficient to compensate for the marked advancement in bone age observed at diagnosis. GnRH agonist treatment seems to have no detrimental effect on bone mineral density.

Tumores adrenocorticais na criança: da abordagem clínica à avaliação molecular

Tumores do córtex adrenal (TCA) são mais frequentes em crianças, mas podem ocorrer em qualquer faixa etária. São classificados como funcionantes, não funcionantes (predominam no adulto), e mistos. O diagnóstico é baseado na avaliação clínica, hormonal e exames de imagem. Em crianças, o método de escolha para diferenciar entre benigno ou maligno é a classificação baseada no estadiamento do tumor. Alguns marcadores moleculares merecem destaque: além de mutações inativadoras no gene supressor tumoral TP53, há evidências de envolvimento do IGF2 em 90% de TAC malignos, e mutações no éxon 3 do gene CTNNB1 foram encontradas em 6% dos TAC pediátricos. Além disso, microRNAs podem atuar como reguladores negativos da expressão gênica e participar da tumorigênese adrenocortical. Métodos para análise da expressão gênica permitem identificar TCA com prognóstico bom ou ruim, e espera-se que esses estudos possam facilitar o desenvolvimento de drogas para tratar pacientes de acordo com as vias de sinalização específicas que estiverem alteradas.

[Mineralocorticoid resistance: pseudohypoaldosteronism type 1]

Pseudohypoaldosteronism type 1 (PHA1) is a rare genetic disease characterized by neonatal renal salt wasting, vomiting, dehydration and failure to thrive. Affected patients present hyponatremia, hyperkalemia, associated with high levels of plasma renin and aldosterone resulting from a renal or systemic resistance to aldosterone. The systemic form of PHA1 results in a severe phenotype, and high doses of salt supplementation are necessary. The symptoms are life-long recurrent. This form is associated with autosomal recessive transmission. Homozygous or compound heterozygous loss of function mutations in the genes coding for the epithelial sodium channel (ENaC) subunities are responsible for this disease. The renal form of PHA1 results in a mild phenotype. Low doses of salt supplementation are required and usually the symptoms remit at the end of the first year of life. Heterozygous loss-of-function mutations in the mineralocorticoid receptor (MR) gene are associated with the renal form of PHA1 in the majority of the affected families but sporadic cases have been reported. In this review the mechanisms of aldosterone action and its effects are discussed. Additionally, clinical and molecular findings of a Brazilian family with the renal form of PHA1 caused by a nonsense mutation (R947X) in the MR gene are presented.

Glucocorticoid receptor gene polymorphisms in ACTH-secreting pituitary tumours

OBJECTIVE

The inhibitory action of glucocorticoids on the hypothalamic-pituitary axis is disrupted in ACTH-secreting pituitary tumours. The molecular events leading to the development of these tumours and their relative resistance to glucocorticoids are unknown. We investigated the presence of mutations and polymorphisms of the glucocorticoid receptor (GR) gene in corticotropinoma and their possible relationship with the tissue-specific resistance to glucocorticoids.

DESIGN AND METHODS

DNA or RNA was extracted from 18 corticotropinomas and the GR gene was amplified by the polymerase chain reaction (PCR) or reverse transcriptase-PCR followed by automated direct sequencing.

RESULTS

We did not identify any mutation in the coding region and the exon-intron boundary regions of the GR gene. The polymorphism AAT > AGT at codon 363 (N363S) was found in 17% and the polymorphism AAT > AAC at codon 766 (N766N) in 11% of tumours, both in heterozygous state. The polymorphisms at codons 22 and 23, at introns 3 and 4, and at codon 618, previously described in normal population, were not observed.

CONCLUSIONS

Our results show that GR gene mutations are rare and unlikely to contribute to the glucocorticoid resistance observed in corticotropinomas. Polymorphisms in the GR gene might confer a selective advantage to tumorigenesis in corticotropinoma. However, there was no relationship between GR gene polymorphism and clinical presentation, tumour size or surgery outcome, suggesting that tumour growth may not be directly related to alterations of the GR gene structure.

Cerebral midline developmental anomalies: endocrine, neuroradiographic and ophthalmological features

BACKGROUND

Hypopituitarism may occur in patients with midline cerebral defects (MCD), including septo-optic dysplasia (SOD). HESX1 gene mutations have been associated with SOD.

OBJECTIVE

To evaluate the endocrine, ophthalmological and neuroradiographic abnormalities in 18 patients with MCD and SOD without mutations at the HESX1 locus.

STUDY DESIGN

The diagnosis of hypothalamic and pituitary abnormalities was confirmed by clinical findings and basal hormone values or functional tests. All patients underwent ophthalmological examination and neuroradiologic studies by MRI.

RESULTS

The diagnosis of hypothalamic and pituitary abnormalities varied from 3 days to 13 years. Endocrine abnormalities were found in 88% of the patients: GH deficiency (72%), hypothyroidism (66%), hypogonadism (45%), diabetes insipidus (27%), adrenal insufficiency (10%), and precocious puberty (5%). Psychomotor retardation was observed in 55% and seizures in 22%. Visual status varied from normal to blindness. MRI confirmed heterogeneous intracranial malformations.

CONCLUSIONS

Our data support the need for systematic and periodic endocrine evaluation of patients with MCD using a multidisciplinary approach.