Newborn Screening for the Detection of the TP53 R337H Variant and Surveillance for Early Diagnosis of Pediatric Adrenocortical Tumors: Lessons Learned and Way Forward

The incidence of pediatric adrenocortical tumors (ACT) is high in southern Brazil due to the founder TP53 R337H variant. Neonatal screening/surveillance (NSS) for this variant resulted in early ACT detection and improved outcomes. The medical records of children with ACT who did not participate in newborn screening (non-NSS) were reviewed (2012–2018). We compared known prognostic factors between the NSS and non-NSS cohorts and estimated surveillance and treatment costs. Of the 16 non-NSS children with ACT carrying the R337H variant, the disease stages I, II, III, and IV were observed in five, five, one, and five children, respectively. The tumor weight ranged from 22 to 608 g. The 11 NSS children with ACT all had disease stage I and were alive. The median tumor weight, age of diagnosis, and interval between symptoms and diagnosis were 21 g, 1.9 years, and two weeks, respectively, for the NSS cohort and 210 g, 5.2 years, and 15 weeks, respectively, for the non-NSS cohort. The estimated surveillance/screening cost per year of life saved is US$623/patient. NSS is critical for improving the outcome of pediatric ACT in this region. Hence, we strongly advocate for the inclusion of R337H in the state-mandated universal screening and surveillance.

Pediatric adrenocortical tumors cohort characteristics and long-term follow-up at a single Argentinian tertiary center

Pediatric adrenocortical tumors are rare and heterogeneous endocrine malignancies. Objectives To report clinical, biochemical, and histological features, staging, and therapeutic interventions in a cohort of 28 patients treated at a single tertiary center. Methods A retrospective review of medical records of children with PACT (diagnosed before <18 years of age) followed between 1987–2018 at Hospital de Pediatría Garrahan, Buenos Aires, Argentina. Results Mean age at diagnosis was 4.6 years (range, 0.3–17.3 years) and median follow-up was 4.17 years (range, 0–12 years). Female to male ratio was 2.5:1. Signs and symptoms that prompted medical intervention were hormonal overproduction (57%), abdominal complaints (36%), and hypertensive encephalopathy (7%). In patients with clinically virilizing tumors (n=16) mean height standard deviation score (SDS) and bone age advance were significantly higher while body mass index (BMI) SDS was significantly lower than in those with clinical Cushing’s (n=10) (p<0.05). Serum dehydroepiandrosterone sulfate (DHEAS) levels were significantly higher in stage IV than in stage I (p=0.03). Total adrenalectomy was performed in 26 patients. Eight patients (stage III-IV) received adjuvant chemotherapy. Five-year overall and disease-free survival were 100% for ST I-II, and 51% (95% CI 21–82) and 33% (95% CI 1.2–65) for ST III-IV, respectively (p=0.002). No statistical difference was found when comparing 2-year parameters with and without adjuvant chemotherapy. Conclusions Height SDS and BMI SDS seem to mirror hormonal secretion in pediatric adrenocortical tumors. Higher DHEAS levels were found in patients with more advanced disease. Further large-scale studies are needed to validate a possible role for DHEAS as a biochemical marker of tumor stage and to draw robust conclusions on the use of adjuvant chemotherapy.

MicroRNA expression profile predicts prognosis of pediatric adrenocortical tumors

Pediatric adrenocortical tumors (ACT) are rare aggressive neoplasms with heterogeneous prognosis. Despite extensive efforts, identifying reliable prognostic factors for pediatric patients with ACT remains a challenge. MicroRNA (miRNA) signatures have been associated with cancer diagnosis, treatment response, and prognosis of several types of cancer. However, the role of miRNAs has been poorly explored in pediatric ACT. In this study, we performed miRNA microarray profiling on a cohort of 37 pediatric ACT and nine non-neoplastic adrenal (NNA) samples and evaluated the prognostic significance of abnormally expressed miRNAs using Kaplan-Meier plots, log-rank test and Cox regression analysis. We identified a total of 98 abnormally expressed miRNAs, which expression profile discriminated ACT from NNAs. Among the 98 deregulated miRNAs, 17 presented significant associations with patients’ survival. In addition, higher expression levels of hsa-miR-630, -139-3p, -125a-3p, -574-5p, -596, -564, -1321, and -423-5p and lower expression levels of hsa-miR-377-3p, -126-3p, -410, -136-3p, -29b-3p, -29a-3p, -337-5p, -143-3p, and 140-5p were significantly associated with poor prognosis, tumor relapse, and/or death. Importantly, the expression profile of these 17 miRNAs stratified patients into two groups of ACTs with different clinical outcomes. Although some individual miRNAs exhibit potential prognostic values in ACTs, only the 17 miRNA-based expression clustering was considered an independent prognostic factor for five-year event-free survival (EFS) compared to other clinicopathological features. In conclusion, our study reports for the first time associations between miRNA profiles and childhood ACT prognosis, providing evidence that miRNAs could be useful biomarkers to discriminate patients with favorable and unfavorable clinical outcomes.

Germline Variants in Phosphodiesterase Genes and Genetic Predisposition to Pediatric Adrenocortical Tumors

Phosphodiesterases (PDEs) form a superfamily of enzymes that catalyze the hydrolysis of cyclic nucleotides adenosine 3′5′-cyclic monophosphate (cAMP) and guanosine 3′5′-cyclic monophosphate (cGMP) to their inactive 5′ monophosphates. cAMP plays a critical role as a second messenger in endocrine tissues, and activation of cAMP signaling has been reported in endocrine tumors. Germline variants in PDEs have been associated with benign cortisol-secreting adrenocortical adenomas and testicular germ cell cancer but not adrenocortical carcinoma. We performed whole genome sequencing (WGS) and whole exome sequencing (WES) of paired blood and tumor samples from 37 pediatric adrenocortical tumors (ACTs). Germline inactivating variants in PDEs were observed in 9 of 37 (24%) patients. Tumor DNA analysis revealed loss of heterozygosity, with maintenance of the mutated allele in all cases. Our results suggest that germline variants in PDEs and other regulators of the cAMP-signaling pathway may contribute to pediatric adrenocortical tumorigenesis, perhaps by cooperating with germline hypomorphic mutant TP53 alleles and uniparental disomy of chromosome 11p15 (Beckwith–Wiedemann syndrome).

DNA Methylation Profiling Reveals Prognostically Significant Groups in Pediatric Adrenocortical Tumors: A Report From the International Pediatric Adrenocortical Tumor Registry

PURPOSE Pediatric adrenocortical carcinomas (ACCs) are aggressive; the overall survival of patients with ACCs is 40%-50%. Appropriate staging and histologic classification are crucial because children with incomplete resections, metastases, or relapsed disease have a dismal prognosis. The clinical course of pediatric adrenocortical tumors (ACTs) is difficult to predict using the current classification schemas, which rely on subjective microscopic and gross macroscopic variables. Recent advances in adult ACT studies have revealed distinct DNA methylation patterns with prognostic significance that have not been systematically interrogated in the pediatric population. PATIENTS AND METHODS We performed DNA methylation analyses on 48 newly diagnosed ACTs from the International Pediatric Adrenocortical Tumor Registry and 12 pediatric adrenal controls to evaluate for distinct methylation groups. Pediatric methylation data were also compared systematically with the adult ACC cohort from The Cancer Genome Atlas (TCGA). RESULTS Two pediatric ACT methylation groups were identified and showed differences in selected clinicopathologic and outcome characteristics. The A1 group was enriched for CTNNB1 variants and unfavorable outcome. The A2 group was enriched for TP53 germline variants, younger age at onset, and favorable outcome. Pediatric ACT methylation groups were maintained when International Pediatric Adrenocortical Tumor Registry cohort data were combined with TCGA cohort data. The CpG-island hypermethylator phenotype characterizing the TCGA cohort was not identified in the pediatric patients. When methylome findings were combined with independent histopathologic review using the Wieneke criteria, a high-risk population was identified with uniform fatal outcome. CONCLUSION Our results indicate DNA methylation analysis can enhance current diagnostic algorithms. A combination of methylation and histologic classification produced the strongest prediction model and may prove useful in future risk-adapted therapeutic trials.