Somatic TP53 mutations are relatively rare among adrenocortical cancers with the frequent 17p13 loss of heterozygosity

Germline NGS targeted analysis in adult patients with sporadic adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare cancer that arises sporadically or due to hereditary syndromes. Data on germline variants (GVs) in sporadic ACC are limited. Our aim was to characterize GVs of genes potentially related to adrenal diseases in 150 adult patients with sporadic ACC.

METHODS

This was a retrospective analysis of stage I-IV ACC patients with sporadic ACC from two reference centers for ACC in Italy. Patients were included in the analysis if they had confirmed diagnosis of ACC, a frozen peripheral blood sample and complete clinical and follow-up data. Next generation sequencing technology was used to analyze the prevalence of GVs in a custom panel of 17 genes belonging to either cancer-predisposition genes or adrenocortical-differentiation genes categories.

RESULTS

We identified 18 GVs based on their frequency, enrichment and predicted functional characteristics. We found six pathogenic (P) or likely pathogenic (LP) variants in ARMC5, CTNNB1, MSH2, PDE11A and TP53 genes; and twelve variants lacking evidence of pathogenicity. New unique P/LP variants were identified in TP53 (p.G105D) and, for the first time, in ARMC5 (p.P731R). The presence of P/LP GVs was associated with reduced survival outcomes and had a significant and independent impact on both progression-free survival and overall survival.

CONCLUSIONS

GVs were present in 6.7 % of patients with sporadic ACC, and we identified novel variants of ARMC5 and TP53. These findings may improve understanding of ACC pathogenesis and enable genetic counseling of patients and their families.

[Adrenocortical cancer: late diagnosis of the disease on the example of a clinical case. Case report]

Adrenocortical carcinoma (ACC) is a rare malignant tumor originating in the adrenal cortex and characterized by poor 5-year survival. It occurs with a frequency of 2-4 cases per 2 million in the population. Women are more frequently affected than men and it is mostly detected in the fourth and fifth decades. In the most of cases, the cancerogenesis occurs sporadically because of gene driver mutations in somatic adrenocortical cells, in other cases it can be found as part of a genetically determined syndrome such as Li-Fraumeni syndrome or Wermer's syndrome (multiple endocrine adenomatosis type I). ACC most frequently happens occurs without symptoms in the initial stages leading to poor diagnoses. Because of this lack of early detection, the tumor is not considered malignant reducing the benefits of further treatment. Sometimes the fact that the resected tumor is indeed adrenocortical carcinoma becomes clear only after recurrence, or after the appearance of metastases. We present a case of adrenocortical carcinoma in a 46-year-old woman who went to the doctor in 1.5 year after symptoms were manfested. This clinical case illustrates the consequences of late diagnosis of a malignant tumor. We would like to emphasize the importance of timely detection of a neoplasm, using all of the potential of laboratory-instrumental and genomic analysis. Due to low oncological awareness, our patient was slow to seek medical help, which in turn led not only to metastases, but also to complications in the cardiovascular system.

[Guidelines of the French National ENDOCAN-COMETE, Association of Endocrine Surgery, Society of Urology for the management of adrenocortical carcinoma]

The adrenocortical carcinoma (ACC) is a primary malignant tumor developed from the adrenal cortex, defined by a Weiss score≥3. Its prognosis is poor and depends mainly on the stage of the disease at diagnosis. Care is organized in France by the multidisciplinary expert centers of the national ENDOCAN-COMETE "Adrenal Cancers" network, certified by the National Cancer Institute. This document updates the guidelines for the management of ACC in adults based on the most robust data in the literature. It's divided into 11 chapters: (1) circumstances of discovery; (2) pre-therapeutic assessment; (3) diagnosis of ACC; (4) oncogenetics; (5) prognostic classifications; (6) treatment of hormonal hypersecretion; (7) treatment of localized forms; (8) treatment of relapses; (9) treatment of advanced forms; (10) follow-up; (11) the particular case of ACC and pregnancy. R0 resection of all localized ACC remains an unmet need and it must be performed in expert centers. Flow-charts for the therapeutic management of localized ACC, relapse or advanced ACC are provided. It was written by the experts from the national ENDOCAN-COMETE network and validated by all French Societies involved in the management of these patients (endocrinology, medical oncology, endocrine surgery, urology, pathology, genetics, nuclear medicine, radiology, interventional radiology).

Histopathologic Features of Adrenal Cortical Carcinoma

Adrenal cortical carcinoma (ACC) is a rare and aggressive malignancy that poses challenging issues regarding the diagnostic workup. Indeed, no presurgical technique or clinical parameters can reliably distinguish between adrenal cortical adenomas, which are more frequent and have a favorable outcome, and ACC, and the final diagnosis largely relies on histopathologic analysis of the surgical specimen. However, even the pathologic assessment of malignancy in an adrenal cortical lesion is not straightforward and requires a combined evaluation of multiple histopathologic features. Starting from the Weiss score, which was developed in 1984, several histopathologic scoring systems have been designed to tackle the difficulties of ACC diagnosis. Dealing with specific histopathologic variants (eg, Liss-Weiss-Bisceglia scoring system for oncocytic ACC) or patient characteristics (eg, Wieneke index in the pediatric setting), these scores remarkably improved the diagnostic workup of ACC and its subtypes. Nevertheless, cases with misleading features or discordant correlations between pathologic findings and clinical behavior still occur. Owing to multicentric collaborative studies integrating morphologic features with ancillary immunohistochemical markers and molecular analysis, ACC has eventually emerged as a multifaceted, heterogenous malignancy, and, while innovative and promising approaches are currently being tested, the future clinical management of patients with ACC will mainly rely on personalized medicine and target-therapy protocols. At the dawn of the new Fifth World Health Organization classification of endocrine tumors, this review will tackle ACC from the pathologist's perspective, thus focusing on the main available diagnostic, prognostic, and predictive tissue-tethered features and biomarkers and providing relevant clinical and molecular correlates.

Molecular Cluster Mining of Adrenocortical Carcinoma via Multi-Omics Data Analysis Aids Precise Clinical Therapy

Adrenocortical carcinoma (ACC) is a malignancy of the endocrine system. We collected clinical and pathological features, genomic mutations, DNA methylation profiles, and mRNA, lncRNA, microRNA, and somatic mutations in ACC patients from the TCGA, GSE19750, GSE33371, and GSE49278 cohorts. Based on the MOVICS algorithm, the patients were divided into ACC1-3 subtypes by comprehensive multi-omics data analysis. We found that immune-related pathways were more activated, and drug metabolism pathways were enriched in ACC1 subtype patients. Furthermore, ACC1 patients were sensitive to PD-1 immunotherapy and had the lowest sensitivity to chemotherapeutic drugs. Patients with the ACC2 subtype had the worst survival prognosis and the highest tumor-mutation rate. Meanwhile, cell-cycle-related pathways, amino-acid-synthesis pathways, and immunosuppressive cells were enriched in ACC2 patients. Steroid and cholesterol biosynthetic pathways were enriched in patients with the ACC3 subtype. DNA-repair-related pathways were enriched in subtypes ACC2 and ACC3. The sensitivity of the ACC2 subtype to cisplatin, doxorubicin, gemcitabine, and etoposide was better than that of the other two subtypes. For 5-fluorouracil, there was no significant difference in sensitivity to paclitaxel between the three groups. A comprehensive analysis of multi-omics data will provide new clues for the prognosis and treatment of patients with ACC.

A Novel TP53 Gene Mutation Sustains Non-Small Cell Lung Cancer through Mitophagy

Lung cancer is the leading cause of cancer death in the world. In particular, non-small-cell lung cancer (NSCLC) represents the majority of the lung cancer population. Advances in DNA sequencing technologies have significantly contributed to revealing the roles, functions and mechanisms of gene mutations. However, the driver mutations that cause cancers and their pathologies remain to be explored. Here, we performed next-generation sequencing (NGS) on tumor tissues isolated from 314 Chinese NSCLC patients and established the mutational landscape in NSCLC. Among 656 mutations, we identified TP53-p.Glu358Val as a driver mutation in lung cancer and found that it activates mitophagy to sustain cancer cell growth. In support of this finding, mice subcutaneously implanted with NSCLC cells expressing TP53-p.Glu358Val developed larger tumors compared to wild-type cells. The pharmaceutical inhibition of autophagy/mitophagy selectively suppresses the cell proliferation of TP53-null or TP53-p.Glu358Val-expressing lung cancer cells. Together, our study characterizes a new TP53 mutation identified from Chinese lung cancer patients and uncovers its roles in regulating mitophagy, providing a new insight into NSCLC treatment.

The role of molecular profiling in adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare, aggressive cancer with still partially unknown pathogenesis, heterogenous clinical behaviour and no effective treatment for advanced stages. Therefore, there is an urgent clinical unmet need for better prognostication strategies, innovative therapies and significant improvement of the management of the individual patients. In this review, we summarize available studies on molecular prognostic markers and markers predictive of response to standard therapies as well as newly proposed drug targets in sporadic ACC. We include in vitro studies and available clinical trials, focusing on alterations at the DNA, RNA and epigenetic levels. We also discuss the potential of biomarkers to be implemented in a clinical routine workflow for improved ACC patient care.

How to Differentiate Benign from Malignant Adrenocortical Tumors?

Simple Summary

Adrenocortical carcinoma is a rare cancer with a poor prognosis. Adrenal tumors are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance to determine the appropriate treatment and follow-up strategy. This review summarizes the current diagnostic strategies and challenges to distinguish benign from malignant adrenal lesions. We will focus both on radiological and biochemical assessments, enabling diagnosis of the adrenal lesion preoperatively, and on histopathological and a wide variety of molecular assessments that can be done after surgical removal of the adrenal lesion. Furthermore, new non-invasive strategies such as liquid biopsies, in which blood samples are used to study circulating tumor cells, tumor DNA and microRNA, will be addressed in this review.

Abstract

Adrenocortical carcinoma (ACC) is a rare cancer with a poor prognosis. Adrenal incidentalomas are, however, commonly identified in clinical practice. Discrimination between benign and malignant adrenal tumors is of great importance considering the large differences in clinical behavior requiring different strategies. Diagnosis of ACC starts with a thorough physical examination, biochemical evaluation, and imaging. Computed tomography is the first-level imaging modality in adrenal tumors, with tumor size and Hounsfield units being important features for determining malignancy. New developments include the use of urine metabolomics, also enabling discrimination of ACC from adenomas preoperatively. Postoperatively, the Weiss score is used for diagnosis of ACC, consisting of nine histopathological criteria. Due to known limitations as interobserver variability and lack of accuracy in borderline cases, much effort has been put into new tools to diagnose ACC. Novel developments vary from immunohistochemical markers and pathological scores, to markers at the level of DNA, methylome, chromosome, or microRNA. Molecular studies have provided insights into the most promising and most frequent alterations in ACC. The use of liquid biopsies for diagnosis of ACC is studied, although in a small number of patients, requiring further investigation. In this review, current diagnostic modalities and challenges in ACC will be addressed.

Two Subsequent Metachroneus Solid Tumors: Oncocytic Variant Adrenocortical Carcinoma and Rhabdomyosarcoma of Childhood: Case Report and Literature Review

Most cases of malignancies appear to be sporadic, but some syndromes are associated with malignancies with germline variants. Herein, a child with an unusual association of oncocytic variant adrenocortical carcinoma (ACC) and rhabdomyosarcoma (RMS) was presented. An 18-month-old-boy was admitted with virilization of the genital area, penis enlargement and erection, which had begun six months earlier. Serum total testosterone (457 ng/dL; NR <10), androstenedione (3.35 ng/mL; NR <0.5) and dehydroepiandrosterone-SO₄ (206 mcg/dL; NR<35) were above the normal ranges. Right adrenal mass was detected. After adrenalectomy, histopathological examination revealed an oncocytic variant ACC. Three-month after surgery, he then presented with 6x8 cm sized swelling of the left leg. Histopathological examination revealed embryonal RMS. Testing for tumor protein (TP53) variant by DNA sequence analysis was positive; however; fluorescence in situ hybridization analysis was negative. After chemotherapy and local radiotherapy, the patient is in good condition without tumor recurrence. Only about one-third of these tumors have a variant of TP53. This status also applies to other genetic variants related to cancer. However, a significant association of malignancies strongly suggests a problem in tumor suppressor genes or new variants. Another as yet unidentified suppressor gene may also be present and effective in this locus. The occurrence of ACC as a part of a syndrome and positive family history of malignancies in patients are clinically important. These patients and their families should be scanned for genetic abnormalities. The patient with ACC should be followed-up carefully for other tumors to detect malignancy early.

The Immunotherapy Landscape in Adrenocortical Cancer

Adrenocortical carcinoma (ACC) is a rare cancer of the adrenal gland that is frequently associated with excess production of adrenal hormones. Although surgical resection may be curative in early-stage disease, few effective therapeutic options exist in the inoperable advanced or metastatic setting. Immunotherapies, inclusive of a broad array of immune-activating and immune-modulating antineoplastic agents, have demonstrated clinical benefit in a wide range of solid and hematologic malignancies. Due to the broad activity across multiple cancer types, there is significant interest in testing these agents in rare tumors, including ACC. Multiple clinical trials evaluating immunotherapies for the treatment of ACC have been conducted, and many more are ongoing or planned. Immunotherapies that have been evaluated in clinical trials for ACC include the immune checkpoint inhibitors pembrolizumab, nivolumab, and avelumab. Other immunotherapies that have been evaluated include the monoclonal antibodies figitumumab and cixutumumab directed against the ACC-expressed insulin-like growth factor 1 (IGF-1) receptor, the recombinant cytotoxin interleukin-13-pseudomonas exotoxin A, and autologous tumor lysate dendritic cell vaccine. These agents have shown modest clinical activity, although nonzero in the case of the immune checkpoint inhibitors. Clinical trials are ongoing to evaluate whether this clinical activity may be augmented through combinations with other immune-acting agents or targeted therapies.

Adrenal Incidentaloma

An adrenal incidentaloma is now established as a common endocrine diagnosis that requires a multidisciplinary approach for effective management. The majority of patients can be reassured and discharged, but a personalized approach based upon image analysis, endocrine workup, and clinical symptoms and signs are required in every case. Adrenocortical carcinoma remains a real concern but is restricted to <2% of all cases. Functional adrenal incidentaloma lesions are commoner (but still probably <10% of total) and the greatest challenge remains the diagnosis and optimum management of autonomous cortisol secretion. Modern-day surgery has improved outcomes and novel radiological and urinary biomarkers will improve early detection and patient stratification in future years to come.

Key MicroRNA's and Their Targetome in Adrenocortical Cancer

Adrenocortical Carcinoma (ACC) is a rare but aggressive malignancy with poor prognosis and limited response to available systemic therapies. Although complete surgical resection gives the best chance for long-term survival, ACC has a two-year recurrence rate of 50%, which poses a therapeutic challenge. High throughput analyses focused on characterizing the molecular signature of ACC have revealed specific micro-RNAs (miRNAs) that are associated with aggressive tumor phenotypes. MiRNAs are small non-coding RNA molecules that regulate gene expression by inhibiting mRNA translation or degrading mRNA transcripts and have been generally implicated in carcinogenesis. This review summarizes the current insights into dysregulated miRNAs in ACC tumorigenesis, their known functions, and specific targetomes. In addition, we explore the possibility of particular miRNAs to be exploited as clinical biomarkers in ACC and as potential therapeutics.

Intratumor heterogeneity of prognostic DNA-based molecular markers in adrenocortical carcinoma

BACKGROUND

The prognosis of adrenocortical carcinoma (ACC) is heterogeneous. Genomic studies have identified ACC subgroups characterized by specific molecular alterations, including features measured at DNA level (somatic mutations, chromosome alterations, DNA methylation), which are closely associated with outcome. The aim of this study was to evaluate intratumor heterogeneity of prognostic molecular markers at the DNA level.

METHODS

Two different tissue samples (primary tumor, local recurrence or metastasis) were analyzed in 26 patients who underwent surgery for primary or recurrent ACC. DNA-related biomarkers with prognostic role were investigated in frozen and paraffin-embedded samples. Somatic mutations of p53/Rb and Wnt/β-catenin pathways were assessed using next-generation sequencing (n = 26), chromosome alteration profiles were determined using SNP arrays (n = 14) and methylation profiles were determined using four-gene bisulfite pyrosequencing (n = 12).

RESULTS

Somatic mutations for ZNRF3, TP53, CTNN1B and CDKN2A were found in 7, 6, 6 and 4 patients, respectively, with intratumor heterogeneity in 8/26 patients (31%). Chromosome alteration profiles were 'Noisy' (numerous and anarchic alterations) in 8/14 and 'Chromosomal' (extended patterns of loss of heterozygosity) in 5/14 of the study samples. For these profiles, no intratumor heterogeneity was observed. Methylation profiles were hypermethylated in 5/12 and non-hypermethylated in 7/12 of the study samples. Intratumor heterogeneity of methylation profiles was observed in 2/12 patients (17%).

CONCLUSIONS

Intratumor heterogeneity impacts DNA-related molecular markers. While somatic mutation can differ, prognostic DNA methylation and chromosome alteration profile seem rather stable and might be more robust for the prognostic assessment.

Update on in-vivo preclinical research models in adrenocortical carcinoma

PURPOSE OF REVIEW

The aim of this review is to summarize recent advances on development of in vivo preclinical models of adrenocortical carcinoma (ACC).

RECENT FINDINGS

Significant progress has been achieved in the underlying molecular mechanisms of adrenocortical tumorigenesis over the last decade, and recent comprehensive profiling analysis of ACC tumors identified several genetic and molecular drivers of this disease. Therapeutic breakthroughs, however, have been limited because of the lack of preclinical models recapitulating the molecular features and heterogeneity of the tumors. Recent publications on genetically engineered mouse models and development of patient-derived ACC xenografts in both nude mice and humanized mice now provide researchers with novel tools to explore therapeutic targets in the context of heterogeneity and tumor microenvironment in human ACC.

SUMMARY

We review current in-vivo models of ACC and discuss potential therapeutic opportunities that have emerged from these studies.

CCNB2 and AURKA overexpression may cause atypical mitosis in Japanese cortisol-producing adrenocortical carcinoma with TP53 somatic variant

Background

Many genomic analyses of cortisol-producing adrenocortical carcinoma (ACC) have been reported, but very few have come from East Asia. The first objective of this study is to verify the genetic difference with the previous reports by analyzing targeted deep sequencing of 7 Japanese ACC cases using next-generation sequencing (NGS). The second objective is to compare the somatic variant findings identified by NGS analysis with clinical and pathological findings, aiming to acquire new knowledge about the factors that contribute to the poor prognosis of ACC and to find new targets for the treatment of ACC.

Method

DNA was extracted from ACC tissue of seven patients and two reference blood samples. Targeted deep sequencing was performed using the MiSeq system for 12 genes, and the obtained results were analyzed using MuTect2. The hypothesis was obtained by integrating the somatic variant findings with clinical and pathological data, and it was further verified using The Cancer Genome Atlas (TCGA) dataset for ACC.

Results

Six possible pathogenic and one uncertain significance somatic variants including a novel PRKAR1A (NM_002734.4):c.545C>A (p.T182K) variant were found in five of seven cases. By integrating these data with pathological findings, we hypothesized that cases with TP53 variants were more likely to show atypical mitotic figures. Using TCGA dataset, we found that atypical mitotic figures were associated with TP53 somatic variant, and mRNA expression of CCNB2 and AURKA was significantly high in TP53 mutated cases and atypical mitotic figure cases.

Conclusion

We believe this is the first report that discusses the relationship between atypical mitotic figures and TP53 somatic variant in ACC. We presumed that overexpression of CCNB2 and AURKA mRNA may cause atypical mitosis in TP53 somatic mutated cases. Because AURKA is highly expressed in atypical mitotic cases, it may be an appropriate indicator for AURKA inhibitors.

IGF2 role in adrenocortical carcinoma biology

PURPOSE

Clinical outcomes of adrenocortical carcinomas (ACC) could be improved by using novel treatment targets based on the recent advances of tumor biology knowledge. Insulin-like growth factor 2 (IGF2) protein expression is usually 8-80 fold higher in ACC when compared to normal adrenal glands (N-AG) or adrenocortical adenomas (ACA), despite the fact that the biological features of high vs. low IGF2 expressing ACC have not yet been well characterized. Our goal was to understand the IGF2 role in ACC biology by focusing in several cancer hallmarks, including cell proliferation, viability, invasion, and metabolism.

METHODS

IGF2 immunohistochemistry expression was evaluated in ACC (n = 13), non-functioning adrenocortical adenoma (ACAn) (n = 14), and N-AG (n = 9). The effects of IGF2 (50, 100 ng/mL) in cell proliferation, viability, invasion, and metabolism, as well as in MAPK/ERK and mTOR pathways activation and N-cadherin expression, were evaluated in the ACC human cell line H295R.

RESULTS

IGF2 expression was increased in ACC compared to ACAn and N-AG. Exposure to 100 ng/mL of IGF2 increased H295R cell proliferation and viability. mTOR inhibition reverted IGF2 triggered cell proliferation and viability while MEK/MAPK/ERK inhibition only reverted IGF2 effects on cell proliferation. IGF2 at a 50 ng/mL concentration increased the glycolytic flux and decreased glutamine consumption.

CONCLUSIONS

IGF2 is an excellent marker to differentiate ACC from ACAn. In addition, IGF2 was demonstrated to influence adrenocortical cancer cell proliferation, metabolism, and viability, but not the cell invasion. These data support that different IGF2 concentrations in ACC can be responsible for different biological behaviors of ACC.

Apoptosis regulation in adrenocortical carcinoma

Apoptosis evading is a hallmark of cancer. Tumor cells are characterized by having an impaired apoptosis signaling, a fact that deregulates the balance between cell death and survival, leading to tumor development, invasion and resistance to treatment. In general, patients with adrenocortical carcinomas (ACC) have an extremely bad prognosis, which is related to disease progression and significant resistance to treatments. In this report, we performed an integrative review about the disruption of apoptosis in ACC that may underlie the characteristic poor prognosis in these patients. Although the apoptosis has been scarcely studied in ACC, the majority of the deregulation phenomena already described are anti-apoptotic. Most importantly, in a near future, targeting apoptosis modulation in ACC patients may become a promising therapeutic.

Management of Adrenocortical Carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy typically with poor prognosis. This review aims to summarize the current knowledge regarding the clinical management of ACC.

RECENT FINDINGS

Surgery remains the cornerstone for localized ACC management. In more advanced cases, debulking surgery when feasible can help with hormonal control and may allow the initiation of systemic therapy. Over the last few years, our understanding of ACC molecular pathogenesis has expanded with no significant change in treatment options. Platinum-based chemotherapy is the gold standard in metastatic ACC despite suboptimal efficacy. Tyrosine kinase inhibitor use did not result in meaningful benefit in ACC patients. Multiple clinical trials are currently exploring the role of immunotherapy in ACC. Despite the remarkable improvement in our understanding of the molecular signature and pathways in ACC, this knowledge did not yield a major breakthrough in management of advanced ACC. Multi-institutional and international collaborations are needed to identify promising treatments and new therapeutic targets to improve the care of ACC patients.

Pathobiology and genetics of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare malignancy with an incidence worldwide of 0.7-2.0 cases/million/year. Initial staging is the most important factor in determining prognosis. If diagnosed early, complete surgical resection +/- adjuvant treatment can lead to 5-year survival of up to 80%. However, often it is diagnosed late and in advanced disease, 5-year survival is <15% with a high recurrence rate even after radical surgery. The mainstay of adjuvant treatment is with the drug mitotane. Mitotane has a specific cytotoxic effect on steroidogenic cells of the adrenal cortex, but despite this, progression through treatment is common. Developments in genetic analysis in the form of next-generation sequencing, aided by bioinformatics, have enabled high-throughput molecular characterisation of these tumours. This, in addition to a better appreciation of the processes of physiological, homeostatic self-renewal of the adrenal cortex, has furthered our understanding of the pathogenesis of this malignancy. In this review, we have detailed the pathobiology and genetic alterations in adrenocortical carcinoma by integrating current understanding of homeostasis and self-renewal in the normal adrenal cortex with molecular profiling of tumours from recent genetic analyses. Improved understanding of the mechanisms involved in self-renewal and stem cell hierarchy in normal human adrenal cortices, together with the identification of cell populations likely to be co-opted by oncogenic mutations, will enable further progress in the definition of the molecular pathways involved in the pathogenesis of ACC. The combination of these advances eventually will lead to the development of novel, effective and personalised strategies to eradicate molecularly annotated ACCs.

Primary malignant tumors of the adrenal glands

Malignancy must be considered in the management of adrenal lesions, including those incidentally identified on imaging studies. Adrenocortical carcinomas (ACCs) are rare tumors with an estimated annual incidence of 0.7-2 cases per year and a worldwide prevalence of 4-12 cases per million/year. However, a much higher incidence of these tumors (>15 times) has been demonstrated in south and southeastern Brazil. Most ACCs cause hypersecretion of steroids including glucocorticoids and androgens. ACC patients have a very poor prognosis with a 5-year overall survival (OS) below 30% in most series. Pheochromocytoma or paraganglioma (PPGL) is a metabolically active tumor originating from the chromaffin cells of the adrenal medulla. The incidence of PPGL is 0.2 to 0.9 cases per 100,000 individuals per year. Pheochromocytomas are present in approximately 4-7% of patients with adrenal incidentalomas. Classically, PPGL manifests as paroxysmal attacks of the following 4 symptoms: headaches, diaphoresis, palpitations, and severe hypertensive episodes. The diagnosis of malignant PPGL relies on the presence of local invasion or metastasis. In this review, we present the clinical and biochemical characteristics and pathogenesis of malignant primary lesions that affect the cortex and medulla of human adrenal glands.

Therapeutic Targets for Adrenocortical Carcinoma in the Genomics Era

Adrenocortical carcinoma (ACC) is a rare and often fatal cancer, affecting ~1 person per million per year worldwide. Approximately 75% of patients with ACC eventually develop metastases and progress on the few available standard-of-care medical therapies, highlighting an incredible need for an improved understanding of the molecular biology of this disease. Although it has long been known that ACC is characterized by certain histological and genetic features (e.g., high mitotic activity, chromosomal instability, and overexpression of IGF2), only in the last two decades of genomics has the molecular landscape of ACC been more thoroughly characterized. In this review, we describe the findings of historical genetics and recent genomics studies on ACC and discuss how underlying concepts emerging from these studies contribute to the current model of critical pathways for adrenocortical carcinogenesis. Integrative synthesis across these studies reveals that ACC consists of three distinct molecular subtypes with divergent clinical outcomes and implicates differential regulation of Wnt signaling, cell cycle, DNA methylation, immune biology, and steroidogenesis in ACC biology. These cellular programs are pharmacologically targetable and may enable the development of therapeutic strategies to improve outcomes for patients facing this devastating disease.

Adjuvant and Neoadjuvant Therapy, Treatment for Advanced Disease, and Genetic Considerations for Adrenocortical Carcinoma: An Update from the SSO Endocrine and Head and Neck Disease Site Working Group

This is the second of a two-part review on adrenocortical carcinoma (ACC) management. While margin-negative resection provides the only potential cure for ACC, recurrence rates remain high. Furthermore, many patients present with locally advanced, unresectable tumors and/or diffuse metastases. As a result, selecting patients for adjuvant therapy and understanding systemic therapy options for advanced ACC is important. Herein, we detail the current literature supporting the use of adjuvant mitotane therapy, consideration of adjuvant radiation therapy, and utility of cytotoxic chemotherapy in patients with advanced disease. Ongoing investigation into molecular targeted agents, immunotherapy, and inhibitors of steroidogenesis for the treatment of ACC are also highlighted. Lastly, the importance of genetic counseling in patients with ACC is addressed as up to 10% of patients will have an identifiable hereditary syndrome.

Clinical and molecular prognostic factors in adrenocortical carcinoma

INTRODUCTION

Adrenocortical carcinoma (ACC) is a rare cancer, with an incidence less than 0.7-1.5 per 1 million people per year, with a poor prognosis. The overall survival (OS) depends on the ENSAT stage: in particular in metastatic ACC the OS varies from 10 to 20 months, with a 5-year survival around 10%. ACC has a different behavior, probably due to a different biology. For this reason, a careful prognostic classification is mandatory, in order to stratify the patients and propose a specific management.

EVIDENCE ACQUISITION

Prognostic factors can be divides in three groups: clinical factors (tumor stage, age, hormone-related symptoms), pathological factors (Weiss Score, mitotic count, Ki-67, SF-1 and AVA2, P53, beta-catenin immunohistochemistry, resection status), molecular factors (chromosomal aberrations, methylation profile, altered gene expression and miRNA expression, gene mutations).

EVIDENCE SYNTHESIS

The best way to stratify ACC patients and propose the best therapeutic option is to combine clinical, pathological and molecular factors.

CONCLUSIONS

Individualizing patients' prognosis and tumor biology appears as a necessary step for personalized medicine. In addition to tumor stage and tumor grade, the genomic classification may precise the risk stratification and thus help defining therapeutic strategy.

Challenges in surgical pathology of adrenocortical tumours

Adrenocortical carcinomas are rare tumours that can be diagnostically challenging. Numerous multiparametric scoring systems and diagnostic algorithms have been proposed to differentiate adrenocortical adenoma from adrenocortical carcinoma. Adrenocortical neoplasms must also be differentiated from other primary adrenal tumours, such as phaeochromocytoma and unusual primary adrenal tumours, as well as metastases to the adrenal gland. Myxoid, oncocytic and sarcomatoid variants of adrenocortical tumours must be recognized so that they are not confused with other tumours. The diagnostic criteria for oncocytic adrenocortical carcinoma are different from those for conventional adrenocortical carcinomas. Adrenocortical neoplasms in children are particularly challenging to diagnose, as histological features of malignancy in adrenocortical neoplasms in adults may not be associated with aggressive disease in the tumours of children. Recent histological and immunohistochemical studies and more comprehensive and integrated genomic characterizations continue to advance our understanding of the tumorigenesis of these aggressive neoplasms, and may provide additional diagnostic and prognostic utility and guide the development of therapeutic targets.

Detailed genomic characterization identifies high heterogeneity and histotype-specific genomic profiles in adrenocortical carcinomas

Molecular characterization of adrenocortical carcinoma has been recently established, but the correlation between molecular profiles and clinical and pathological characteristics is still poorly defined with no data available about genetic heterogeneity along disease progression. In this scenario, a detailed molecular profile was correlated with clinical and pathological characteristics in adrenocortical carcinoma patients to identify potentially novel biomarkers. Targeted next-generation sequencing and copy number variation analyses for 18 most frequently altered genes in adrenocortical carcinoma were assessed on 62 adult cases (including 10 with matched primary and metastatic/recurrence samples) and results correlated with major clinical and pathological characteristics of tumors. A total of 433 somatic deleterious genetic alterations (328 gene mutations and 105 copy number variations) were identified in 57/62 cases, five resulted wild type for all genes tested. TERT, CDK4, ZNRF3,and RB1 were altered in more than 30% of cases. Among histological variants genotypes were significantly different. Lowest mutation burden was found in the oncocytic type (p = 0.006), whereas the highest with a prevalence of RB1 (p = 0.001) and CDK4 (p = 0.002) was found in the conventional and myxoid ones, respectively. None of the 10 cases with matched samples showed a stable genotype along tumor progression, although allelic frequencies or percentages of altered nuclei at fluorescence in situ hybridization were in most cases similar among different tumor samples for genes that were stable along tumor progression. Among individual genes, an altered p53/Rb1 pathway was the strongest adverse molecular signature, being associated with high Ki-67 index, high tumor stage, aggressive disease status, and shorter disease-free survival. The genomic signature in adrenocortical carcinoma is changing along tumor progression and is associated with specific clinical and pathological features, including histological variant and prognosis.

MECHANISMS OF ENDOCRINOLOGY: Cell cycle regulation in adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are rather rare endocrine tumors that often have a poor prognosis. The reduced survival rate associated with these tumors is due to their aggressive biological behavior, combined with the scarcity of effective treatment options that are currently available. The recent identification of the genomic alterations present in ACC have provided further molecular mechanisms to develop consistent strategies for the diagnosis, prevention of progression and treatment of advanced ACCs. Taken together, molecular and genomic advances could be leading the way to develop personalized medicine in ACCs similarly to similar developments in lung or breast cancers. In this review, we focused our attention to systematically compile and summarize the alterations in the cell cycle regulation that were described so far in ACC as they are known to play a crucial role in cell differentiation and growth. We have divided the analysis according to the major transition phases of the cell cycle, G1 to S and G2 to M. We have analyzed the most extensively studied checkpoints: the p53/Rb1 pathway, CDC2/cyclin B and topoisomerases (TOPs). We reached the conclusion that the most important alterations having a potential application in clinical practice are the ones related to p53/Rb1 and TOP 2. We also present a brief description of on-going clinical trials based on molecular alterations in ACC. The drugs have targeted the insulin-like growth factor receptor 1, TOP 2, polo-like kinase1, cyclin-dependent kinase inhibitors, p53 reactivation and CDC25.

Epigenetic dysregulation in adrenocortical carcinoma, a systematic review of the literature

Adrenocortical carcinoma (ACC) is a rare and aggressive endocrine malignancy with a poor prognosis. Diagnosis and treatment of this tumor remains challenging. The Weiss score, the current gold standard for the histopathological diagnosis of ACC, lacks diagnostic accuracy of borderline tumors (Weiss score 2 or 3) and is subject to inter observer variability. Furthermore, adjuvant and palliative systemic therapy have limited effect and no proven overall survival benefit. A better insight in the molecular background of ACC might identify markers that improve diagnostic accuracy, predict treatment response or even provide novel therapeutic targets. This systematic review of the literature aims to provide an overview of alterations in DNA methylation, histone modifications and their potential clinical relevance in ACC.

MANAGEMENT OF ENDOCRINE DISEASE: Adrenocortical carcinoma: differentiating the good from the poor prognosis tumors

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis, the five-years overall survival being below 40%. However, there is great variability of outcomes and we have now a better view of the heterogeneity of tumor aggressiveness. The extent of the disease at the time of diagnosis, best assayed by the European Network for the Study of Adrenal Tumors (ENSAT) Staging Score, is a major determinant of survival. The tumor grade, including the mitotic count and the Ki67 proliferation index, also appears as a strong prognostic factor. The assessment of tumor grade, even by expert pathologists, still suffers from inter-observer reproducibility. The emergence of genomics in the last decade has revolutionized the knowledge of molecular biology and genetics of cancers. In ACC, genomic approaches - including pan-genomic studies of gene expression (transcriptome), recurrent mutations (exome or whole-genome sequencing), chromosome alterations, DNA methylation (methylome), miRNA expression (miRnome) - converge in a new classification of ACC, characterized by distinct molecular profiles and very different outcomes. Targeted measurements of a few discriminant molecular alterations have been developed in the perspective of clinical routine, and thus, may help defining therapeutic strategy. By individualizing patients' prognosis and tumor biology, these recent progresses appear as an important step forward towards precision medicine.

Identification of Clinical and Biologic Correlates Associated With Outcome in Children With Adrenocortical Tumors Without Germline TP53 Mutations: A St Jude Adrenocortical Tumor Registry and Children's Oncology Group Study

Purpose The clinical features, pathogenesis, and outcomes in children with adrenocortical tumors (ACTs) without germline TP53 mutations have not been systematically studied. Herein, we describe these correlates and analyze their association with outcome. Patients and Methods Genomic DNA was analyzed for TP53, CTNNB1, CDKN1C, ATRX, and chromosome 11p15 abnormalities. β-catenin expression and Ki-67 labeling index (LI) were evaluated by immunostaining. Primary end points were progression-free (PFS) and overall survival. Results Median age of 42 girls and 18 boys was 3.3 years (range, 0.25 to 21.7 years). Complete resection (stages I and II) was achieved in 32 patients, and 28 patients had stage III or IV disease. Constitutional abnormalities of chromosome 11p15 occurred in nine of 40 patients, with six patients not showing phenotype of Beckwith-Wiedemann syndrome. Three-year PFS and overall survival for all patients were 71.4% and 80.5%, respectively. In single-predictor Cox regression analysis, age, disease stage, tumor weight, somatic TP53 mutations, and Ki-67 LI were associated with prognosis. Ki-67 LI and age remained significantly associated with PFS after adjusting for stage and tumor weight. Three-year PFS for 27 patients with Ki-67 LI ≥ 15% was 48.5% compared with 96.2% for 29 patients with Ki-67 LI < 15% (log-rank P = .002), and the rate of relapse increased by 24% with each 1-year increase in age at diagnosis (hazard ratio, 1.24; P = .0057). Conclusion Clinicopathologic features and outcomes of children with ACTs without germline TP53 mutations overlapped those reported for children with germline TP53 mutations. Our findings highlight the central role of genetic or epigenetic alterations on chromosome 11p15 in pediatric ACTs. Ki-67 LI is a strong prognostic indicator and should be investigated to improve the histologic classification of pediatric ACTs.

Molecular targeted therapies in adrenal, pituitary and parathyroid malignancies

Tumourigenesis is a relatively common event in endocrine tissues. Currently, specific guidelines have been developed for common malignant endocrine tumours, which also incorporate advances in molecular targeted therapies (MTT), as in thyroid cancer and in gastrointestinal neuroendocrine malignancies. However, there is little information regarding the role and efficacy of MTT in the relatively rare malignant endocrine tumours mainly involving the adrenal medulla, adrenal cortex, pituitary, and parathyroid glands. Due to the rarity of these tumours and the lack of prospective studies, current guidelines are mostly based on retrospective data derived from surgical, locoregional and ablative therapies, and studies with systemic chemotherapy. In addition, in many of these malignancies the prognosis remains poor with individual patients responding differently to currently available treatments, necessitating the development of new personalised therapeutic strategies. Recently, major advances in the molecular understanding of endocrine tumours based on genomic, epigenomic, and transcriptome analysis have emerged, resulting in new insights into their pathogenesis and molecular pathology. This in turn has led to the use of novel MTTs in increasing numbers of patients. In this review, we aim to present currently existing and evolving data using MTT in the treatment of adrenal, pituitary and malignant parathyroid tumours, and explore the current utility and effectiveness of such therapies and their future evolution.

P53/Rb inhibition induces metastatic adrenocortical carcinomas in a preclinical transgenic model

Adrenocortical carcinoma (ACC) is a rare cancer with poor prognosis. Pan-genomic analyses identified p53/Rb and WNT/β-catenin signaling pathways as main contributors to the disease. However, isolated β-catenin constitutive activation failed to induce malignant progression in mouse adrenocortical tumors. Therefore, there still was a need for a relevant animal model to study ACC pathogenesis and to test new therapeutic approaches. Here, we have developed a transgenic mice model with adrenocortical specific expression of SV40 large T-antigen (AdTAg mice), to test the oncogenic potential of p53/Rb inhibition in the adrenal gland. All AdTAg mice develop large adrenal carcinomas that eventually metastasize to the liver and lungs, resulting in decreased overall survival. Consistent with ACC in patients, adrenal tumors in AdTAg mice autonomously produce large amounts of glucocorticoids and spontaneously activate WNT/β-catenin signaling pathway during malignant progression. We show that this activation is associated with downregulation of secreted frizzled related proteins (Sfrp) and Znrf3 that act as inhibitors of the WNT signaling. We also show that mTORC1 pathway activation is an early event during neoplasia expansion and further demonstrate that mTORC1 pathway is activated in ACC patients. Preclinical inhibition of mTORC1 activity induces a marked reduction in tumor size, associated with induction of apoptosis and inhibition of proliferation that results in normalization of corticosterone plasma levels in AdTAg mice. Altogether, these data establish AdTAg mice as the first preclinical model for metastatic ACC.

Targeting polo-like kinase 1, a regulator of p53, in the treatment of adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is an aggressive cancer with a 5 year survival rate of 20-30 %. Various factors have been implicated in the pathogenesis of ACC including dysregulation of the G2/M transition and aberrant activity of p53 and MDM2. Polo-like kinase 1 (PLK-1) negatively modulates p53 functioning, promotes MDM2 activity through its phosphorylation, and is involved in the G2/M transition. Gene expression profiling of 44 ACC samples showed that increased expression of PLK-1 in 29 % of ACC. Consequently, we examined PLK-1's role in the modulation of the p53 signaling pathway in adrenocortical cancer.

METHODS

We used siRNA knock down PLK-1 and pharmacological inhibition of PLK-1 and MDM2 ACC cell lines SW-13 and H295R. We examined viability, protein expression, p53 transactivation, and induction of apoptosis.

RESULTS

Knocking down expression of PLK-1 with siRNA or inhibition of PLK-1 by a small molecule inhibitor, BI-2536, resulted in a loss of viability of up to 70 % in the ACC cell lines H295R and SW-13. In xenograft models, BI-2536 demonstrated marked inhibition of growth of SW-13 with less inhibition of H295R. BI-2536 treatment resulted in a decrease in mutant p53 protein in SW-13 cells but had no effect on wild-type p53 protein levels in H295R cells. Additionally, inhibition of PLK-1 restored wild-type p53's transactivation and apoptotic functions in H295R cells, while these functions of mutant p53 were restored only to a smaller extent. Furthermore, inhibition of MDM2 with nutlin-3 reduced the viability of both the ACC cells and also reactivated wild-type p53's apoptotic function. Inhibition of PLK-1 sensitized the ACC cell lines to MDM2 inhibition and this dual inhibition resulted in an additive apoptotic response in H295R cells with wild-type p53.

CONCLUSIONS

These preclinical studies suggest that targeting p53 through PLK-1 is an attractive chemotherapy strategy warranting further investigation in adrenocortical cancer.

Diagnosis and Management of Hereditary Adrenal Cancer

Benign adrenocortical tumours (ACT) are relatively frequent lesions; on the contrary, adrenocortical carcinoma (ACC) is a rare and aggressive malignancy with unfavourable prognosis. Recent advances in the molecular understanding of adrenal cancer offer promise for better therapies in the future. Many of these advances stem from the molecular elucidation of genetic conditions predisposing to the development of ACC. Six main clinical syndromes have been described to be associated with hereditary adrenal cancer. In these conditions, genetic counselling plays an important role for the early detection and follow-up of the patients and the affected family members.

Molecular Profiling of Refractory Adrenocortical Cancers and Predictive Biomarkers to Therapy

PURPOSE

Current first-line chemotherapy for patients with metastatic adrenocortical cancer (ACC) includes doxorubicin, etoposide, cisplatin, and mitotane with a reported response rate of only 23.2%. New therapeutic leads for patients with refractory tumors are needed; there is no standard second-line treatment.

METHODS

Samples from 135 ACC tumors were analyzed by immunohistochemistry, in situ hybridization (FISH or CISH), and/or gene sequencing at a single commercial reference laboratory (Caris Life Sciences) to identify markers associated with drug sensitivity and resistance.

RESULTS

Overexpression of proteins related to demonstrated chemotherapy sensitivity or resistance included topoisomerase 1, progesterone receptor, and topoisomerase 2-alpha in 46%, 63%, and 42% of cases, respectively. Loss of excision repair cross-complementary group 1 (ERCC1), phosophatase and tensin homolog, O(6)-methylguanine-methyltransferase, and ribonucleotide reductase M1 (RRM1) was identified in 56%, 59%, 71%, and 58% of cases, respectively. Other aberrations included overexpression of programmed death-ligand 1 or programmed cell death protein 1 tumor-infiltrating lymphocytes in >40% of cases. In all, 35% of cases had a mutation in the canonical Wnt signaling pathway (either CTNNB1 or APC) and 48% had a mutation in TP53. No other genomic alterations were identified.

CONCLUSION

Biomarker alterations in ACC may be used to direct therapies, including recommendations for and potential resistance of some patients to traditional chemotherapies, which may explain the low response rate in the unselected population. Limited outcomes data support the use of mitotane and platinum therapies for patients with low levels of the proteins RRM1 and ERCC1.

Development of adrenal cortex zonation

The human adult adrenal cortex is composed of the zona glomerulosa (zG), zona fasciculata (zF), and zona reticularis (zR), which are responsible for production of mineralocorticoids, glucocorticoids, and adrenal androgens, respectively. The final completion of cortical zonation in humans does not occur until puberty with the establishment of the zR and its production of adrenal androgens; a process called adrenarche. The maintenance of the adrenal cortex involves the centripetal displacement and differentiation of peripheral Sonic hedgehog-positive progenitors cells into zG cells that later transition to zF cells and subsequently zR cells.

Surgical management of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is rare but one of the most malignant endocrine tumors. This article reviews and summarizes the current knowledge about the treatment of ACC. The epidemiology and molecular events involved in the pathogenesis of ACC are briefly outlined. The different diagnostic tools to distinguish benign from malignant adrenocortical tumors, including biochemical analysis and imaging, are discussed. The surgical treatment of ACC has evolved in the last 2 decades. The different surgical alternatives for the treatment of ACC in the context of primary, recurrent, or metastatic disease are reviewed, and the remaining challenges and controversies are discussed.

The genetics of adrenocortical tumors

Advances in genomics accelerated greatly progress in the study of the genetics adrenocortical tumors. Bilateral nodular hyperplasias causing Cushing's syndrome are frequently caused by germline alterations leading to cAMP/PKA pathway activation (micronodular) and ARMC5 inactivation (macronodular). Somatic mutations of β-catenin and PRKACA are observed in non secreting or cortisol producing adenomas, respectively. Alterations of the β-catenin (CTNN1B, ZNFR3) or TP53 pathways are found in carcinomas. Mutations in cancers are more common in aggressive tumors and correlate with transcriptome or methylation profiles. Identification of these alterations helps to refine the molecular classification of these tumors and to develop molecular diagnostic tools.

Whole-exome sequencing characterizes the landscape of somatic mutations and copy number alterations in adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and lethal malignancy with a poorly defined etiology, and the molecular genetics of ACC are incompletely understood.

OBJECTIVE

To utilize whole-exome sequencing for genetic characterization of the underlying somatic mutations and copy number alterations present in ACC.

DESIGN

Screening for somatic mutation events and copy number alterations (CNAs) was performed by comparative analysis of tumors and matched normal samples from 41 patients with ACC.

RESULTS

In total, 966 nonsynonymous somatic mutations were detected, including 40 tumors with a mean of 16 mutations per sample and one tumor with 314 mutations. Somatic mutations in ACC-associated genes included TP53 (8/41 tumors, 19.5%) and CTNNB1 (4/41, 9.8%). Genes with potential disease-causing mutations included GNAS, NF2, and RB1, and recurrently mutated genes with unknown roles in tumorigenesis comprised CDC27, SCN7A, and SDK1. Recurrent CNAs included amplification at 5p15.33 including TERT (6/41, 14.6%) and homozygous deletion at 22q12.1 including the Wnt repressors ZNRF3 and KREMEN1 (4/41 9.8% and 3/41, 7.3%, respectively). Somatic mutations in ACC-established genes and recurrent ZNRF3 and TERT loci CNAs were mutually exclusive in the majority of cases. Moreover, gene ontology identified Wnt signaling as the most frequently mutated pathway in ACCs.

CONCLUSIONS

These findings highlight the importance of Wnt pathway dysregulation in ACC and corroborate the finding of homozygous deletion of Wnt repressors ZNRF3 and KREMEN1. Overall, mutations in either TP53 or CTNNB1 as well as focal CNAs at the ZNRF3 or TERT loci denote mutually exclusive events, suggesting separate mechanisms underlying the development of these tumors.

Adrenocortical growth and cancer

The adrenal gland consists of two distinct parts, the cortex and the medulla. Molecular mechanisms controlling differentiation and growth of the adrenal gland have been studied in detail using mouse models. Knowledge also came from investigations of genetic disorders altering adrenal development and/or function. During embryonic development, the adrenal cortex acquires a structural and functional zonation in which the adrenal cortex is divided into three different steroidogenic zones. Significant progress has been made in understanding adrenal zonation. Recent lineage tracing experiments have accumulated evidence for a centripetal differentiation of adrenocortical cells from the subcapsular area to the inner part of the adrenal cortex. Understanding of the mechanism of adrenocortical cancer (ACC) development was stimulated by knowledge of adrenal gland development. ACC is a rare cancer with a very poor overall prognosis. Abnormal activation of the Wnt/β-catenin as well as the IGF2 signaling plays an important role in ACC development. Studies examining rare genetic syndromes responsible for familial ACT have played an important role in identifying genetic alterations in these tumors (like TP53 or CTNNB1 mutations as well as IGF2 overexpression). Recently, genomic analyses of ACT have shown gene expression profiles associated with malignancy as well as chromosomal and methylation alterations in ACT and exome sequencing allowed to describe the mutational landscape of these tumors. This progress leads to a new classification of these tumors, opening new perspectives for the diagnosis and prognostication of ACT. This review summarizes current knowledge of adrenocortical development, growth, and tumorigenesis.

IGF2 promotes growth of adrenocortical carcinoma cells, but its overexpression does not modify phenotypic and molecular features of adrenocortical carcinoma

Insulin-like growth factor 2 (IGF2) overexpression is an important molecular marker of adrenocortical carcinoma (ACC), which is a rare but devastating endocrine cancer. It is not clear whether IGF2 overexpression modifies the biology and growth of this cancer, thus more studies are required before IGF2 can be considered as a major therapeutic target. We compared the phenotypical, clinical, biological, and molecular characteristics of ACC with or without the overexpression of IGF2, to address these issues. We also carried out a similar analysis in an ACC cell line (H295R) in which IGF2 expression was knocked down with si- or shRNA. We found no significant differences in the clinical, biological and molecular (transcriptomic) traits between IGF2-high and IGF2-low ACC. The absence of IGF2 overexpression had little influence on the activation of tyrosine kinase pathways both in tumors and in H295 cells that express low levels of IGF2. In IGF2-low tumors, other growth factors (FGF9, PDGFA) are more expressed than in IGF2-high tumors, suggesting that they play a compensatory role in tumor progression. In addition, IGF2 knock-down in H295R cells substantially impaired growth (>50% inhibition), blocked cells in G1 phase, and promoted apoptosis (>2-fold). Finally, analysis of the 11p15 locus showed a paternal uniparental disomy in both IGF2-high and IGF2-low tumors, but low IGF2 expression could be explained in most IGF2-low ACC by an additional epigenetic modification at the 11p15 locus. Altogether, these observations confirm the active role of IGF2 in adrenocortical tumor growth, but also suggest that other growth promoting pathways may be involved in a subset of ACC with low IGF2 expression, which creates opportunities for the use of other targeted therapies.

Genetics and epigenetics of adrenocortical tumors

Adrenocortical tumors are common neoplasms. Most are benign, nonfunctional and clinically irrelevant. However, adrenocortical carcinoma is a rare disease with a dismal prognosis and no effective treatment apart from surgical resection. The molecular genetics of adrenocortical tumors remain poorly understood. For decades, molecular studies relied on a small number of samples and were directed to candidate-genes. This approach, based on the elucidation of the genetics of rare genetic syndromes in which adrenocortical tumors are a manifestation, has led to the discovery of major dysfunctional molecular pathways in adrenocortical tumors, such as the IGF pathway, the Wnt pathway and TP53. However, with the advent of high-throughput methodologies and the organization of international consortiums to obtain a larger number of samples and high-quality clinical data, this paradigm is rapidly changing. In the last decade, genome-wide expression profile studies, microRNA profiling and methylation profiling allowed the identification of subgroups of tumors with distinct genetic markers, molecular pathways activation patterns and clinical behavior. As a consequence, molecular classification of tumors has proven to be superior to traditional histological and clinical methods in prognosis prediction. In addition, this knowledge has also allowed the proposal of molecular-targeted approaches to provide better treatment options for advanced disease. This review aims to summarize the most relevant data on the rapidly evolving field of genetics of adrenal disorders.

The 'omics' of adrenocortical tumours for personalized medicine

Pan-genomic analyses of genetic and epigenetic alterations and gene expression profiles are providing important new insights into the pathogenesis and molecular classification of cancers. The technologies and methods used for these studies are rapidly diversifying and improving. The use of such methodologies for the analysis of adrenocortical tumours has revealed clear transcriptomic (mRNA and microRNA expression profiles), epigenomic (DNA methylation profiles) and genomic (DNA mutations and chromosomal alterations) differences between benign and malignant tumours. Interestingly, genomic studies of adrenal cancers have also identified subtypes of malignant tumours, which demonstrate distinct patterns of molecular alterations and are associated with different clinical outcomes. These discoveries have created the opportunity for classifying adrenocortical tumours on the basis of molecular analyses. Following these genomic studies, efforts to develop new molecular tools that improve diagnosis and prognostication of patients with adrenocortical tumours have also been made. This Review describes the progress that has been made towards classification of adrenocortical tumours to date based on key genomic approaches. In addition, the potential for the development and use of various molecular tools to personalize the management of patients with adrenocortical tumours is discussed.

Mass-array screening of frequent mutations in cancers reveals RB1 alterations in aggressive adrenocortical carcinomas

CONTEXT

Adrenocortical carcinoma (ACC) is a rare disease with a poor overall outcome. Transcriptome analysis identified two groups of ACCs with different prognosis. In aggressive ACCs, somatic mutations of the tumor suppressor gene TP53 and the proto-oncogene β-catenin are detected in 50% of cases. For the remaining aggressive ACCs and for the group with a better prognosis, molecular alterations are unknown.

OBJECTIVE

To identify new molecular actors driving adrenal tumorigenesis.

EXPERIMENTAL DESIGN

Analysis by mass array of 374 mutations among 32 common oncogenes or tumor suppressor genes was performed on the tumoral DNA of 26 ACCs, using Sequenom OncoCarta Panels.

RESULTS

Four mutations were identified, two previously known β-catenin mutations and one alteration in two other genes: JAK3 and retinoblastoma gene (RB1). The JAK3 alteration was found in leukocyte DNA and therefore considered as a polymorphism and not a somatic event. The full RB1 tumor suppressor gene was subsequently sequenced in a cohort of 49 ACCs (26 ACCs from the 'OncoCarta cohort' and 23 other ACCs): three somatic mutations were identified, all in the poor-outcome ACC group. By immunohistochemistry, a loss of the retinoblastoma protein (pRb) was found exclusively in aggressive ACCs in 27% of cases (seven out of 26), three of them with an inactivating RB1 mutation. Among the seven pRb-negative ACCs, five had an allele loss at the RB1 locus.

CONCLUSIONS

Parallel analysis of somatic mutations among known cancer genes allowed us to identify RB1 as a new actor in aggressive ACCs. These results suggest a prognostic significance of pRb expression loss in ACCs.

Pathology of the adrenal cortex: a reappraisal of the past 25 years focusing on adrenal cortical tumors

A reappraisal of the major advances in the diagnostic pathology of adrenal cortical lesions and tumors in the last 25 years is presented, with special reference to the definition of malignancy in primary adrenal cancer and its variants. Slightly more than 25 years ago, Weiss proposed his diagnostic scoring system for adrenal cortical carcinoma. This represented a milestone for adrenal pathologists and the starting point for further modifications of the system, either through minor changes in the scoring procedure itself or concentrating on some particular Weiss criterion such as mitotic index, integrated into alternative scoring schemes or algorithms that are currently under validation. Improvements in diagnostic immunohistochemistry have led to the identification of markers of cortical origin, such as Melan-A, alpha-inhibin, and SF-1 and of prognostic factors in carcinoma, such as the Ki-67 proliferation index and SF-1 itself. With regard to hyperplastic conditions, genetic investigations have allowed the association of the majority of cases of primary pigmented nodular adrenocortical disease (PPNAD) in Carney complex to mutations in the gene encoding the regulatory subunit 1A of protein kinase A (PRKAR1A). Other hereditary conditions are also associated with adrenal cortical tumors, including the Li-Fraumeni, Beckwith-Wiedemann, Gardner, multiple endocrine neoplasia type 1, and neurofibromatosis type 1 syndromes. Moreover, several advances have been made in the knowledge of the molecular background of sporadic tumors, and a number of molecules/genes are of particular interest as potential diagnostic and prognostic biomarkers.

Molecular markers and targeted therapies for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a lethal disease with poor prognosis and lack of effective therapeutic options. Systemic treatment is often employed to treat patients with advanced ACC, but outcomes are disappointing. During the last decade, some of the causative genetic mutations in sporadic ACCs have been identified. Molecular analysis has had a significant impact on the understanding of the pathogenetic mechanism of ACC development and the evaluation of prognostic and predictive markers. Preclinical investigations and clinical trials of tyrosine kinase inhibitors and anti-angiogenic compounds have been initiated to seek target therapy of ACCs. This review summarizes the current view of molecular alterations involved in the pathophysiology of adrenocortical carcinogenesis. The rationale for testing targeted therapies of ACC is also presented.

Long-term study of subclinical Cushing's syndrome shows high prevalence of extra-adrenal malignancy in patients with functioning bilateral adrenal tumors

Subclinical Cushing's syndrome (SCS) is characterized by subtle autonomous cortisol secretion from adrenal tumors without specific signs and symptoms of hypercortisolism. Patients with SCS have a high prevalence of "lifestyle-related diseases," such as hypertension, diabetes mellitus, dyslipidemia, and osteoporosis. Long-term follow-up of SCS patients is reportedly indispensable for establishing indications for surgical treatment of SCS. We performed a follow-up survey of 27 patients with SCS (median: 5.3 years) and compared those who had undergone surgical treatment (n=15) with those who had not (n=12). The mean diameter of tumors was 31 mm; 16 (59%) patients had unilateral lesions and 11 (41%) carried bilateral ones. In 67% and 60% of the treatment group, respectively, hypertension and diabetes mellitus improved. We also noticed that eight of 11 (73%) SCS patients with bilateral adrenal tumors had extra-adrenal malignancies in various tissues. Interestingly, among nine SCS patients who had malignancies, eight showed bilateral adrenal uptake in ¹³¹I-aldosterol scintigraphy. The results imply that surgical treatment can reduce cardiovascular risks in SCS patients. Screening for malignancy may be necessary in patients with bilateral adrenal tumors suspected of autonomous hypersecretion of cortisol from both sides.

ARMC5 mutations in macronodular adrenal hyperplasia with Cushing's syndrome

BACKGROUND

Corticotropin-independent macronodular adrenal hyperplasia may be an incidental finding or it may be identified during evaluation for Cushing's syndrome. Reports of familial cases and the involvement of both adrenal glands suggest a genetic origin of this condition.

METHODS

We genotyped blood and tumor DNA obtained from 33 patients with corticotropin-independent macronodular adrenal hyperplasia (12 men and 21 women who were 30 to 73 years of age), using single-nucleotide polymorphism arrays, microsatellite markers, and whole-genome and Sanger sequencing. The effects of armadillo repeat containing 5 (ARMC5) inactivation and overexpression were tested in cell-culture models.

RESULTS

The most frequent somatic chromosome alteration was loss of heterozygosity at 16p (in 8 of 33 patients for whom data were available [24%]). The most frequent mutation identified by means of whole-genome sequencing was in ARMC5, located at 16p11.2. ARMC5 mutations were detected in tumors obtained from 18 of 33 patients (55%). In all cases, both alleles of ARMC5 carried mutations: one germline and the other somatic. In 4 patients with a germline ARMC5 mutation, different nodules from the affected adrenals harbored different secondary ARMC5 alterations. Transcriptome-based classification of corticotropin-independent macronodular adrenal hyperplasia indicated that ARMC5 mutations influenced gene expression, since all cases with mutations clustered together. ARMC5 inactivation decreased steroidogenesis in vitro, and its overexpression altered cell survival.

CONCLUSIONS

Some cases of corticotropin-independent macronodular adrenal hyperplasia appear to be genetic, most often with inactivating mutations of ARMC5, a putative tumor-suppressor gene. Genetic testing for this condition, which often has a long and insidious prediagnostic course, might result in earlier identification and better management. (Funded by Agence Nationale de la Recherche and others.).

Molecular screening for a personalized treatment approach in advanced adrenocortical cancer

CONTEXT

Adrenocortical cancer (ACC) is a rare cancer with poor prognosis and scant treatment options. In ACC, no personalized approach has emerged but no extensive molecular screening has been performed to date.

OBJECTIVE

The objective of the study was to evaluate the presence of a large number of potentially targetable molecular events in a large cohort of advanced ACC.

DESIGN, SETTING, AND PARTICIPANTS

We used hot spot gene sequencing (Ion Torrent, 40 patients) and comparative genomic hybridization (CGH; 28 patients; a subset of the entire cohort) in adult stage III-IV ACC samples to screen for mutations and copy number abnormalities of potential interest for therapeutic use in 46 and 130 genes, respectively.

RESULTS

At least one copy number alteration or mutation was found in 19 patients (47.5%). The most frequent mutations were detected on TP53, ATM, and CTNNB1 [6 of 40 (15%), 5 of 40 (12.5%), and 4 of 40 (10%), respectively]. The most frequent copy number alterations identified were: amplification of the CDK4 oncogene (5 of 28; 17.9%) and deletion of the CDKN2A (4 of 28; 14.3%) and CDKN2B (3 of 28; 10.7%) tumor suppressor genes. Amplifications of FGFR1, FGF9, or FRS2 were discovered in three subjects (10.7%). Associated alterations were: deletions of CDKN2A, CDKN2B with ATM mutations, and TP53 mutations with CTNNB1 mutations.

CONCLUSIONS

No simple targetable molecular event emerged. Drugs targeting the cell cycle could be the most relevant new therapeutic approach for patients with advanced ACC. Inhibitors of the fibroblast growth factor receptor pathway could also be a therapeutic option in a subset of patients, whereas other targeted therapies should be considered on a case-by-case basis.