Treatment of advanced adrenocortical carcinoma with erlotinib plus gemcitabine

Adrenocortical Cancer in the Real World: A Comprehensive Analysis of Clinical Features and Management from the Turkish Oncology Group (TOG)

INTRODUCTION

Adrenocortical carcinoma (ACC) is a rare yet highly malignant tumor associated with significant morbidity and mortality. This study aims to delineate the clinical features, survival patterns, and treatment modalities of ACC, providing insights into the disease's prognosis.

MATERIALS AND METHODS

A retrospective analysis of 157 ACC patients was performed to assess treatment methodologies, demographic patterns, pathological and clinical attributes, and laboratory results. The data were extracted from the hospital's database. Survival analyses were conducted using the Kaplan-Meier method, with univariate and multivariate analyses being performed through the log-rank test and Cox regression analyses.

RESULTS

The median age was 45, and 89.4% had symptoms at the time of diagnosis. The median tumor size was 12 cm. A total of 117 (79.6%) patients underwent surgery. A positive surgical border was detected in 26 (24.1%) patients. Adjuvant therapy was administered to 44.4% of patients. The median overall survival for the entire cohort was 44.3 months. Median OS was found to be 87.3 months (95% confidence interval [CI] 74.4-100.2) in stage 2, 25.8 (95% CI 6.5-45.1) months in stage 3, and 13.3 (95% CI 7.0-19.6) months in stage 4 disease. Cox regression analysis identified age, Ki67 value, Eastern Cooperative Oncology Group performance status, and hormonal activity as significant factors associated with survival in patients with nonmetastatic disease. In metastatic disease, only patients who underwent surgery exhibited significantly improved overall survival in univariate analyses.

CONCLUSION

ACC is an uncommon tumor with a generally poor prognosis. Understanding the defining prognostic factors in both localized and metastatic diseases is vital. This study underscores age, Ki67 value, Eastern Cooperative Oncology Group performance status, and hormonal activity as key prognostic determinants for localized disease, offering critical insights into the complexities of ACC management and potential avenues for targeted therapeutic interventions.

Advances in translational research of the rare cancer type adrenocortical carcinoma

Adrenocortical carcinoma is a rare malignancy with an annual worldwide incidence of 1-2 cases per 1 million and a 5-year survival rate of <60%. Although adrenocortical carcinoma is rare, such rare cancers account for approximately one third of patients diagnosed with cancer annually. In the past decade, there have been considerable advances in understanding the molecular basis of adrenocortical carcinoma. The genetic events associated with adrenocortical carcinoma in adults are distinct from those of paediatric cases, which are often associated with germline or somatic TP53 mutations and have a better prognosis. In adult primary adrenocortical carcinoma, the main somatic genetic alterations occur in genes that encode proteins involved in the WNT-β-catenin pathway, cell cycle and p53 apoptosis pathway, chromatin remodelling and telomere maintenance pathway, cAMP-protein kinase A (PKA) pathway or DNA transcription and RNA translation pathways. Recently, integrated molecular studies of adrenocortical carcinomas, which have characterized somatic mutations and the methylome as well as gene and microRNA expression profiles, have led to a molecular classification of these tumours that can predict prognosis and have helped to identify new therapeutic targets. In this Review, we summarize these recent translational research advances in adrenocortical carcinoma, which it is hoped could lead to improved patient diagnosis, treatment and outcome.

Feasibility and Activity of Megestrol Acetate in Addition to Etoposide, Doxorubicin, Cisplatin, and Mitotane as First-Line Therapy in Patients with Metastatic/Unresectable Adrenocortical Carcinoma with Low Performance Status

(1) Background: The standard first-line therapy for advanced adrenocortical carcinoma (ACC) is represented by EDP-M (etoposide, doxorubicin, cisplatin + mitotane). Progestins have shown cytotoxic activity both in vitro and in vivo on ACC; better EDP-M tolerability and efficacy have been hypnotized due to the association with progestins. (2) Methods: The feasibility and tolerability of EDP-M combined with oral megestrol acetate (EDP-MM) were tested in 24 patients (pts) affected by metastatic ACC with a low performance status (PS); the case group was compared with a 48 pts control group according to the propensity score. The secondary objectives were clinical benefit rate (CBR), progression-free survival (PFS), and overall survival (OS). (3) Results: Thirteen pts (54.2%) in the EDP-MM population experienced progestin-related toxicities; in particular, five pts experienced vaginal bleeding (20.8%); four pts experienced weight gain (16.7%); and thromboembolic events, worsening of hypertension, skin rashes, and hyperglycemia were registered in one patient each (4.2%). This led to the discontinuation of megestrol acetate in four pts (16.7%). EDP-M-related toxicities were similar in both groups. No differences in PFS and OS curves were observed; the CBR was 75.0% and 60.4%, respectively. (4) Conclusions: The association of EDP-M + megestrol acetate in ACC pts with a low PS is feasible and well tolerated; its efficacy appeared to be non-inferior to EDP-M administered to pts with a good PS.

Treatment of adrenocortical carcinoma: oncological and endocrine outcomes

PURPOSE OF REVIEW

Adrenocortical carcinoma (ACC) is a rare, aggressive disease with a paucity of data and great variability between published studies regarding its treatment. This review provides information on current clinical management and oncological and endocrine outcomes.

RECENT FINDINGS

Complete surgical resection is the only potentially curative treatment for adrenocortical carcinoma (ACC). Adjuvant mitotane treatment is recommended in patients with favourable/intermediate prognosis. As part of the endocrine follow-up, steroid hormones and thyroid hormones may be decreased or increased and may need to be substituted or suppressed. Recurrences are common. If the disease-free interval is more than 12 months, surgery is a treatment if complete resection is feasible. In advanced/metastatic ACC patients, the prognosis is poor. Mitotane monotherapy is only appropriate for patients with low tumour burden and indolent disease. Patients with unfavourable prognosis should be treated with aggressive cytotoxic therapy. Patients requiring third-line treatment should be considered for clinical trials. Immunotherapy and targeted therapy are currently being investigated, but have so far yielded only unsatisfactory results.

SUMMARY

There is scarce evidence for the treatment of ACC, which often complicates clinical decision-making. Patients who progress on EDP-M should be treated in clinical trials.

Advances in adrenocortical carcinoma pharmacotherapy: what is the current state of the art?

INTRODUCTION

Surgery, followed or not by adjuvant mitotane, is the current mainstay of therapy for patients with early-stage adrenocortical carcinoma (ACC). Mitotane, either alone or in association with EDP (Etoposide-Doxorubicin-Cisplatin) combination chemotherapy, is the standard approach for patients with metastatic ACC.

AREAS COVERED

The activity of newer cytotoxic drugs, radioligands, targeted therapies and immunotherapy, both in preclinical and in clinical studies, will be reviewed in this paper.

EXPERT OPINION

ADIUVO trial revealed that the administration of adjuvant mitotane is not advantageous in patients with good prognosis. Future strategies are to intensify efforts in adjuvant setting in patients with high risk of relapse. In patients with advanced/metastatic disease, modern targeted therapies have shown significant cytotoxicity in preclinical studies, however, studies in ACC patients reported disappointing results so far. The absence of targeted agents specifically inhibiting the major molecular pathways of ACC growth is the main cause of the failure of these drugs. Since ACC is often antigenic but poorly immunogenic, the results of immunotherapy trials appeared inferior to those achieved in the management of patients with other malignancies. Radioligand therapy may also be a promising approach. Combination of chemotherapy plus immunotherapy could be interesting to be tested in the future.

Targeted Therapy for Adrenocortical Carcinoma: A Genomic-Based Search for Available and Emerging Options

In rare diseases such as adrenocortical carcinoma (ACC), in silico analysis can help select promising therapy options. We screened all drugs approved by the FDA and those in current clinical studies to identify drugs that target genomic alterations, also known to be present in patients with ACC. We identified FDA-approved drugs in the My Cancer Genome and National Cancer Institute databases and identified genetic alterations that could predict drug response. In total, 155 FDA-approved drugs and 905 drugs in clinical trials were identified and linked to 375 genes of 89 TCGA patients. The most frequent potentially targetable genetic alterations included TP53 (20%), BRD9 (13%), TERT (13%), CTNNB1 (13%), CDK4 (7%), FLT4 (7%), and MDM2 (7%). We identified TP53-modulating drugs to be possibly effective in 20-26% of patients, followed by the Wnt signaling pathway inhibitors (15%), Telomelysin and INO5401 (13%), FHD-609 (13%), etc. According to our data, 67% of ACC patients exhibited genomic alterations that might be targeted by FDA-approved drugs or drugs being tested in current clinical trials. Although there are not many current therapy options directly targeting reported ACC alterations, this study identifies emerging options that could be tested in clinical trials.

Simulation-Based Interpretation of Therapeutically Monitored Cabozantinib Plasma Concentration in Advanced Adrenocortical Carcinoma with Hemodialysis

BACKGROUND

Adrenocortical carcinoma is an orphan but aggressive malignancy with limited treatment options. Cabozantinib (CAB), a tyrosine kinase inhibitor, has emerged as a new potential treatment. However, no data are available on whether and how CAB can be administered to patients undergoing hemodialysis.

METHODS

An liquid chromatography with tandem mass spectrometry detection method was developed and validated according to the European Medicines Agency and United States Food and Drug Administration guidelines for bioanalytical method validation. The samples were prepared using protein precipitation and online solid-phase extraction. The method was applied to clinical samples of an adrenocortical carcinoma patient receiving CAB treatment (80 mg daily). During the 10 days of observation, the patient received periodic hemodialysis on 7 days. Pharmacokinetic (PK) simulations were performed using Bayesian forecasting according to an existing population PK model for CAB.

RESULTS

Based on the PK simulation, a mean plasma trough concentration of 1375 ng/mL [90% prediction interval (PI), 601-2602 ng/mL] in the steady state at a daily dose of 80 mg was expected for CAB. However, an individual simulation involving the measured plasma levels of the patient resulted in a mean trough concentration of 348 ng/mL (90% PI, 278-430 ng/mL). The model based on individual PK parameters estimated accessible plasma levels of 521, 625, and 834 ng/mL by dose adjustment to 100, 120, and 160 mg, respectively.

CONCLUSIONS

After establishing an liquid chromatography with tandem mass spectrometry detection method for therapeutic drug monitoring of CAB, our analyses involving a single patient undergoing hemodialysis indicated that higher than expected doses of CAB were required to achieve reasonable plasma concentrations. Our study demonstrates the usefulness of therapeutic drug monitoring for the evaluation of "new" drugs in patients with renal impairment.

Management of adrenocortical carcinoma: are we making progress?

Adrenocortical carcinoma (ACC) is a rare malignancy characterized by aggressive biology and potential endocrine activity. Surgery can offer cure for localized disease but more than half of patients relapse and primary unresectable or metastasized disease is frequent. Prognosis of metastatic ACC is still limited, with less than 15% of patients alive at 5 years. Recent advances in understanding the molecular profile of ACC underline the high complexity of this disease, which is characterized by limited drugable molecular targets as well as by a complex interplay between a yet scarcely understood microenvironment and potential endocrine activity. Particularly steroid-excess further complicates therapeutic concepts such as immunotherapy, which have markedly improved outcome in other disease entities. To date, mitotane remains the only approved drug for adjuvant and palliative care in ACC. Standard chemotherapy-based protocols with cisplatin, doxorubicin and etoposide offer only marginal improvement in long-term outcome and the number of clinical trials conducted is low due to the rarity of the disease. In the current review, we summarize principles of oncological management for ACC from localized to advanced disease and discuss novel therapeutic strategies, including targeted therapies such as tyrosine kinase inhibitors and antibodies, immunotherapy with a focus on checkpoint inhibitors, individualized treatment concepts based on molecular characterization by next generation sequencing methods, the role of theranostics and evolvement of adjuvant therapy.

Novel Insights into the Molecular Regulation of Ribonucleotide Reductase in Adrenocortical Carcinoma Treatment

Simple Summary

The current clinical gold standard etoposide, doxorubicin, cisplatin, and mitotane (EDP-M) is not satisfying for the treatment of adrenocortical carcinoma (ACC). However, clinical translation of novel, preclinically promising therapies were unfortunately disappointing in recent years, indicating that utilized tumor models inadequately predicted clinical applicability of novel pharmacological approaches. In an attempt to optimize the current preclinical armamentarium, our workgroup initiated a comparative drug screen of clinically relevant chemotherapies and therapies targeting IGF, EGF, and Wnt signaling pathways in the classical NCI-H295R cell line and, for the first time, in the recently developed highly drug-resistant MUC-1 cell line. These testings revealed gemcitabine and cisplatin as a promising combination, but further investigations also indicated developing drug resistance mechanisms on the molecular level. We aimed to decipher underlying resistance mechanisms, identified ribonucleotide reductase as an important player, and successfully targeted the involved DNA damage/repair mechanism.

Abstract

Current systemic treatment options for patients with adrenocortical carcinomas (ACCs) are far from being satisfactory. DNA damage/repair mechanisms, which involve, e.g., ataxia-telangiectasia-mutated (ATM) and ataxia-telangiectasia/Rad3-related (ATR) protein signaling or ribonucleotide reductase subunits M1/M2 (RRM1/RRM2)-encoded ribonucleotide reductase (RNR) activation, commonly contribute to drug resistance. Moreover, the regulation of RRM2b, the p53-induced alternative to RRM2, is of unclear importance for ACC. Upon extensive drug screening, including a large panel of chemotherapies and molecular targeted inhibitors, we provide strong evidence for the anti-tumoral efficacy of combined gemcitabine (G) and cisplatin (C) treatment against the adrenocortical cell lines NCI-H295R and MUC-1. However, accompanying induction of RRM1, RRM2, and RRM2b expression also indicated developing G resistance, a frequent side effect in clinical patient care. Interestingly, this effect was partially reversed upon addition of C. We confirmed our findings for RRM2 protein, RNR-dependent dATP levels, and modulations of related ATM/ATR signaling. Finally, we screened for complementing inhibitors of the DNA damage/repair system targeting RNR, Wee1, CHK1/2, ATR, and ATM. Notably, the combination of G, C, and the dual RRM1/RRM2 inhibitor COH29 resulted in previously unreached total cell killing. In summary, we provide evidence that RNR-modulating therapies might represent a new therapeutic option for ACC.

Targeted genomic analysis of 364 adrenocortical carcinomas

Despite recent advances in elucidating molecular pathways underlying adrenocortical carcinoma (ACC), this orphan malignancy is associated with poor survival. Identification of targetable genomic alterations is critical to improve outcomes. The objective of this study was to characterize the genomic profile of a large cohort of patient ACC samples to identify actionable genomic alterations. Three hundred sixty-four individual patient ACC tumors were analyzed. The median age of the cohort was 52 years and 60.9% (n = 222) were female. ACC samples had common alterations in epigenetic pathways with 38% of tumors carrying alterations in genes involved in histone modification, 21% in telomere lengthening, and 21% in SWI/SNF complex. Tumor suppressor genes and WNT signaling pathway were each mutated in 51% of tumors. Fifty (13.7%) ACC tumors had a genomic alteration in genes involved in the DNA mismatch repair (MMR) pathway with many tumors also displaying an unusually high number of mutations and a corresponding MMR mutation signature. In addition, genomic alterations in several genes not previously associated with ACC were observed, including IL7R, LRP1B, FRS2 mutated in 6, 8 and 4% of tumors, respectively. In total, 58.5% of ACC (n = 213) had at least one potentially actionable genomic alteration in 46 different genes. As more than half of ACC have one or more potentially actionable genomic alterations, this highlights the value of targeted sequencing for this orphan cancer with a poor prognosis. In addition, significant incidence of MMR gene alterations suggests that immunotherapy is a promising therapeutic for a considerable subset of ACC patients.

Adrenocortical carcinoma: current state of the art, ongoing controversies, and future directions in diagnosis and treatment

Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy with an annual incidence of ~1 case per million population. Differentiating between ACC and benign adrenocortical tumors can be challenging in patients who present with an incidentally discovered adrenal mass, due to the limited specificity of standard diagnostic imaging. Recently, urine steroid metabolite profiling has been prospectively validated as a novel diagnostic tool for the detection of malignancy with improved accuracy over current modalities. Surgery represents the only curative treatment for ACC, although local recurrence and metastases are common, even after a margin-negative resection is performed. Unlike other intra-abdominal cancers, the role of minimally invasive surgery and lymphadenectomy in ACC is controversial. Adjuvant therapy with the adrenolytic drug mitotane is used to reduce the risk of recurrence after surgery, although evidence supporting its efficacy is limited; it is also currently unclear whether all patients or a subset with the highest risk of recurrence should receive this treatment. Large-scale pan-genomic studies have yielded insights into the pathogenesis of ACC and have defined distinct molecular signatures associated with clinical outcomes that may be used to improve prognostication. For patients with advanced ACC, palliative combination chemotherapy with mitotane is the current standard of care; however, this is associated with poor response rates (RR). Knowledge from molecular profiling studies has been used to guide the development of novel targeted therapies; however, these have shown limited efficacy in early phase trials. As a result, there is an urgent unmet need for more effective therapies for patients with this devastating disease.

Emerging drugs for the treatment of adrenocortical carcinoma

Introduction: Adrenocortical cancer (ACC) is a rare and aggressive disease with a median survival of 14-17 months and 5-year survival of around 20% for advanced disease. Emerging evidence of sub-groups of ACC with specific molecular drivers indicate ACC may be amenable to inhibition of receptor tyrosine kinases involved in growth and angiogenic signaling. A significant subset of patients may also be responsive to immune strategies.Areas covered: This review outlines approaches of targeting upregulated growth pathways including Insulin-like Growth Factor, Vascular Endothelial Growth Factor, Fibroblast Growth Factor and Epidermal Growth Factor Receptor in ACC. Data of immune checkpoint blockade with nivolumab, ipilimumab, pembrolizumab and avelumab is explored in detail. Genomic studies indicate that up to 40% of ACC are driven by dysregulated WNT and glucocorticoid signaling, special focus is placed on emerging drugs in these pathways.Expert opinion: Progress in the treatment of ACC has faced challenges stemming from the rarity of the disease. Given recent advances in the understanding of the molecular pathogenesis of ACC, a window of opportunity has now opened to make significant progress in developing therapeutic options that target key pathways such as excessive glucocorticoid signaling, WNT signaling, cell cycle and immune checkpoints.

Bioinformatic analyses and experimental validation of the role of m6A RNA methylation regulators in progression and prognosis of adrenocortical carcinoma

M6A-related genes have been proven to play an important role in many cancers. However, the role of that in adrenocortical carcinoma (ACC) has not been fully elucidated. In the present study, 77 ACC samples from TCGA database were divided into localized (n = 46) and metastatic (n = 31) groups. Three differential expression genes (DEGs) and five prognostic m6A genes were screened out. M6A-related risk signature (RBM15 and HNRNPC) was constructed by the Lasso regression analysis. In TCGA cohort (training cohort), the risk signature was identified as an ACC-independent prognostic factor and can distinguish the prognostic difference of ACC patients with clinical stage I-II, T3-4 and N0 stages. A nomogram combining T stage and m6A risk score was constructed to predict the overall survival rate (OSR) of individual at 1,2,3 year. Meanwhile, its prognostic value was also confirmed in the validation cohort (GSE33371 dataset). The potential associations between m6A risk level and immune checkpoint inhibitors (ICIs) therapy were also investigated via the TISIDB online tool. High m6A risk not only can suppress immunotherapy-related biological processes, but also repress the expressions of immune-checkpoint markers. Moreover, five pairs of clinical specimens were collected to confirm the overexpression of HNRNPC and non-ectopic expression of RBM15 in tumor tissues. HNRNPC was proven to promote the proliferation, migration and invasion of H295R and SW13 cells through MTT and Transwell assays. In conclusion, the m6A-related risk signature was beneficial for prognostic analysis and can affect immune microenvironment in ACC. HNRNPC played a pro-cancer role in ACC progression.

Adrenocortical Carcinoma in Eight Children: A Report and Literature Review

Objective

This study aimed to summarize the clinical characteristics, comprehensive treatment, and prognosis of adrenocortical carcinoma (ACC) in children.

Methods

The clinical data of eight children with definite diagnoses of ACC were retrospectively analyzed, and statistical methods were used to analyze the clinical characteristics, comprehensive treatment mode, and prognosis of these patients.

Results

(1) Clinical characteristics: two were males and six were females with the median age of onset was six-years old were involved. Four patients had a rash and precocious puberty as the symptoms of onset. European Network for the Study of Adrenal Tumors (ENSAT) staging: stage II, two patients; stage IV, six patients. (2) Comprehensive treatment: all eight patients underwent surgical treatment and received six cycles of chemotherapy: the regimen was “etoposide + pirarubicin + cisplatin + mitotane.” (3) Prognosis analysis: among these eight patients, two patients died, two patients achieved complete remission, the disease was stable in four patients, and the overall five-year survival rate was 75%. Prognosis analyzed according to ENSAT staging (stage II versus stage IV) revealed that two-year survival rates of the two groups were 100% versus 65%, respectively, without statistical significant (χ² = 1.066, P = 0.302). Prognosis analyzed according to Weiss score (Weiss score was <6, five patients;≥6, three patients) revealed That survival time of the two groups was 50±9.52 months versus 6±1.70 months, the two-year survival rates of the two groups were 100% versus 35%, and the difference in survival rates between these two groups was statistically significant (χ² = 4.091, P = 0.043).

Conclusion

The Weiss score is an important prognostic factor for ACC. The chemotherapy regimen “mitotane + etoposide + adriamycin + cisplatin” is recommended.

The Role of Immunotherapy in the Treatment of Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare epithelial neoplasm, with a high tendency for local invasion and distant metastases, with limited treatment options. Surgical treatment is the method of choice. For decades, the mainstay of pharmacological treatment has been the adrenolytic drug mitotane, in combination with chemotherapy. Immunotherapy is the latest revolution in cancer therapy, however preliminary data with single immune checkpoint inhibitors showed a modest activity in ACC patients. The anti-neoplastic activity of immune checkpoint inhibitors such as anti-cytotoxic-T-lymphocyte-associated-antigen 4 (anti-CTLA-4), anti-programmed death-1 (anti-PD-1), and anti-PD-ligand-1 (PD-L1) antibodies in different solid tumors has aroused interest to explore the potential therapeutic effect in ACC as well. Multiple ongoing clinical trials are currently evaluating the role of immune checkpoint inhibitors in ACC (pembrolizumab, combination pembrolizumab and relacorilant, nivolumab, combination nivolumab and ipilimumab). The primary and acquired resistance to immunotherapy continue to counter treatment efficacy. Therefore, attempts are made to combine therapy: anti-PD-1 antibody and anti-CTLA-4 antibody, anti-PD-1 antibody and antagonist of the glucocorticoid receptor. The inhibitors of immune checkpoints would benefit patients with antitumor immunity activated by radiotherapy. Immunotherapy is well tolerated by patients; the most frequently observed side effects are mild. The most common adverse effects of immunotherapy are skin and gastrointestinal disorders. The most common endocrinopathy during anti-CTLA treatment is pituitary inflammation and thyroid disorders.

Clinical Prognostic Factors in Patients With Metastatic Adrenocortical Carcinoma Treated With Second Line Gemcitabine Plus Capecitabine Chemotherapy

Gemcitabine plus Capecitabine (Gem/Cape) is a frequently adopted second line chemotherapy for metastatic adrenocortical carcinoma (ACC), but only a minority of patients is destined to obtain a clinical benefit. The identification of baseline predictive factors of efficacy is relevant. We retrospectively analyzed clinical data from 50 consecutive patients with metastatic progressing ACC treated between 2011 and 2019. Patients received intravenous Gemcitabine and oral Capecitabine on a metronomic schedule. Previous mitotane therapy was maintained. Clinical benefit (partial response + stable disease) at 4 months was 30%, median progression-free survival (PFS) and disease-specific survival (DSS) from Gem/Cape start were 3 and 8 months, respectively. Among clinical variables evaluated before the start of Gem/Cape, presence of ECOG performance status ≥1 [HR 6.93 95% confidence interval (CI) 0.03-0.54, p.004] and neutrophil-to-lymphocyte ratio (NLR) ≥5 [HR 3.88, 95% (CI) 0.81-0.90, p.003] were independent indicators of poor PFS at multivariate analysis. Conversely, surgery of primary tumor, the presence of lung or lymph-node metastases, blood mitotane level, anemia, and the Advanced Lung cancer Inflammation index (ALI) failed to be independently associated. This study confirms that the Gem/Cape schedule is modestly active in heavily pretreated ACC patients (28% received at least two previous chemotherapy lines). NLR and performance status (PS) are easily available clinical parameters that are helpful to identify patients not likely to derive significant advantage from Gem/Cape chemotherapy.

Medical management of adrenocortical carcinoma: Current recommendations, new therapeutic options and future perspectives

Adrenocortical carcinoma is a rare malignant tumor of poor prognosis, frequently requiring additional treatments after initial surgery. Due to its adrenolytic action, mitotane has become the first-line medical treatment in patients with aggressive adrenocortical carcinoma. Over the last 2years, apart from the classical chemotherapy based on etoposide and platinum salts, several studies reported the use of drugs such as temozolomide, tyrosine kinase inhibitors or immunotherapy, with more or less convincing results. The aim of this review is to give further insights in the use of these drugs, and to describe potential therapeutic perspectives based on recent pangenomic studies, for the future management of these still difficult to treat tumors.

Medical Approaches in Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) represents one of the most aggressive endocrine tumors. In spite of a correct therapeutic strategy based on a multidisciplinary approach between endocrinologist, surgeon and oncologist, the prognosis is often poor. Surgery is the mainstay treatment in ACC. Mitotane, a dichloro-diphenyl-trichloro-ethane derivate, represents the main medical treatment of ACC in consideration of its adrenocytolitic activity and it is mainly employed as adjuvant treatment after complete surgical resection and for the treatment of advanced ACC. However, the use of mitotane as adjuvant therapy is still controversial, also in consideration of the retrospective nature of several studies. The recurrence of disease is frequent, especially in advanced disease at the diagnosis. Therefore, in these contexts, conventional chemotherapy must be considered in association with mitotane, being the combination etoposide, doxorubicin and cisplatin (EDP) the standard of care in this setting. A more modern therapeutic approach, based on the need of a salvage therapy for advanced ACC that progresses through first-line EDP, is focused on molecular-targeted therapies. However, robust clinical trials are necessary to assess the real efficacy of these treatments.

Past, Present and Future of Epigenetics in Adrenocortical Carcinoma

DNA methylation profiling has been suggested a reliable technique to distinguish between benign and malignant adrenocortical tumors, a process which with current diagnostic methods remains challenging and lacks diagnostic accuracy of borderline tumors. Accurate distinction between benign and malignant adrenal tumors is of the essence, since ACC is a rare but aggressive endocrine disease with an annual incidence of about 2.0 cases per million people per year. The estimated five-year overall survival rate for ACC patients is <50%. However, available treatment regimens are limited, in which a radical surgical resection is the only curable option. Nevertheless, up to 85% of patients with radical resection show recurrence of the local disease often with concurrent metastases. Adrenolytic therapy with mitotane, administered alone or in combination with cytotoxic agents, is currently the primary (palliative) treatment for patients with advanced ACC and is increasingly used in adjuvant setting to prevent recurrence. Prognostic stratification is important in order to individualize adjuvant therapies. On April 1, 2020, there were 7404 publications on adrenocortical carcinoma (adrenocortical carcinoma) OR adrenocortical carcinoma [MeSH Terms]) OR adrenal cortex cancer[MeSH Terms]) OR adrenal cortical carcinoma [MeSH Terms]) OR adrenal cortex neoplasm [MeSH Terms]) OR adrenocortical cancer [MeSH Terms]), yet the underlying pathophysiology and characteristics of ACC is not fully understood. Knowledge on epigenetic alterations in the process of adrenal tumorigenesis is rapidly increasing and will add to a better understanding of the pathogenesis of ACC. DNA methylation profiling has been heralded as a promising method in the prognostication of ACC. This review summarizes recent findings on epigenetics of ACC and its role in diagnosis, prognosis and therapeutic strategies.

Objective Response and Prolonged Disease Control of Advanced Adrenocortical Carcinoma with Cabozantinib

BACKGROUND

Objective response of advanced adrenocortical carcinoma (ACC) to mitotane and cytotoxic chemotherapy regimen is only ~20% and early tumor progression is frequent. Previous clinical trials with oral multikinase inhibitors were negative, which has been attributed in part to inadvertent drug interaction with mitotane. Cabozantinib (CABO) is an inhibitor of c-MET, vascular endothelial growth factor receptor 2, AXL, and RET and approved for advanced kidney cancer, liver carcinoma after previous sorafenib, and medullary thyroid carcinoma.

OBJECTIVE

To investigate the clinical efficacy and safety of CABO monotherapy in ACC patients.

DESIGN

Retrospective cohort study.

SETTING

Three referral centers for ACC (Germany, United States).

RESULTS

Sixteen patients (13 female) with progressive ACC received CABO after previous mitotane in 15/16 and 3 (median, range 0-8) further systemic treatments. Prior CABO therapy, mitotane was discontinued in all patients. Mitotane plasma concentration was <2 mg/L in 7/16 patients and discontinued >12 months in 6 additional patients before CABO use. In 4/5 cases with available plasma samples, CABO concentration was in the expected steady-state range. Adverse events of grade 1/2 and 3 were observed in 13 and 3 patients, respectively, and consistent with the known safety profile of CABO. Best response was partial response in 3, stable disease in 5, and progressive disease in 8 patients. Median progression-free and overall survival was 16 and 58 weeks, respectively.

CONCLUSION

CABO monotherapy appears to be safe and effective as a monotherapy in advanced ACC after failing prior treatments. Therefore, prospective investigation of CABO in ACC patients is warranted.

Next-generation therapies for adrenocortical carcinoma

Almost one decade ago, etoposide, doxorubicin, cisplatin and mitotane (EDP-M) has been established as first-line systemic therapy of metastatic adrenocortical carcinoma (ACC). Although heterogeneous, the prognosis of advanced stage ACC is still poor and novel treatments are urgently needed. This article provides a short summary of current systemic ACC treatment and provides a comprehensive overview of new therapeutic approaches that have been investigated in the past years, including drugs targeting the IGF pathway, tyrosine kinase inhibitors, radionuclide treatment, and immunotherapy. The results of most of these trials were disappointing and we will discuss possible reasons why these drugs failed (e.g. drug interactions with mitotane, disease heterogeneity with exceptional responses in very few patients, and resistance mechanisms to immunotherapy). We then will present potential new drug targets that have emerged from many molecular studies (e.g. wnt/β-catenin, cyclin-dependent kinases, PARP1) that may be the foundation of next-generation therapies of ACC.

Advanced Adrenocortical Carcinoma (ACC): a Review with Focus on Second-Line Therapies

Advanced adrenocortical cancer (ACC) is a rare, highly aggressive malignancy, which typically has a poor prognosis. In advanced ACC, the overall trend is toward a short PFS interval following first-line systemic therapy, highlighting a clear need for improved second-/third-line treatment strategies. We conducted a review of the literature and relevant scientific guidelines related to systemic therapy for advanced ACC. Public indexes including PubMed/MEDLINE were searched. Treatment selection in the second-line setting is based on small phase 2 trials, case reports, and pre-clinical evidence. The best data available for initial second-line therapy selection supports the use of gemcitabine and capecitabine (G + C) or streptozotocin (S), both with or without mitotane. G + C is becoming increasingly recommended based on phase 2 clinical trial data in patients of good PS, due to the inferred superior PFS and OS from non-comparative trials. Alternatively, streptozotocin was better tolerated than EDP + M in the FIRM-ACT study and remains an option when warranted. Beyond this, further treatment approaches should be tailored to individual patient characteristics, utilizing a mixture of systemic therapies, local therapies, and enrolment in clinical trials where available. Additionally, the role of molecular stratification, predictive biomarkers, and immune checkpoint inhibitors in specific individuals, such as Lynch syndrome, is evolving and may become increasingly utilized in clinical practice. Advanced ACC necessitates a multidisciplinary approach and is best managed in a specialist center. Although there is no one definitive second-line treatment strategy, there are some favorable approaches, which require further validation in larger clinical trials.

Targeted Gene Expression Profile Reveals CDK4 as Therapeutic Target for Selected Patients With Adrenocortical Carcinoma

Adrenocortical carcinomas (ACC) are aggressive tumors with a heterogeneous prognosis and limited therapeutic options for advanced stages. This study aims to identify novel drug targets for a personalized treatment in ACC. RNA was isolated from 40 formalin-fixed paraffin-embedded ACC samples. We evaluated gene expression of 84 known cancer drug targets by reverse transcriptase quantitative real time-PCR and calculated fold change using 5 normal adrenal glands as reference (overexpression by fold change >2.0). The most promising candidate cyclin-dependent kinase 4 (CDK4) was investigated at protein level in 104 ACC samples and tested by in vitro experiments in two ACC cell lines (NCI-H295R and MUC1). The most frequently overexpressed genes were TOP2A (100% of cases, median fold change = 16.5), IGF2 (95%, fold change = 52.9), CDK1 (80%, fold change = 6.7), CDK4 (62%, fold change = 2.6), PLK4 (60%, fold change = 2.8), and PLK1 (52%, fold change = 2.3). CDK4 was chosen for functional validation, as it is actionable by approved CDK4/6-inhibitors (e.g., palbociclib). Nuclear immunostaining of CDK4 significantly correlated with mRNA expression (R = 0.52, P < 0.005). We exposed both NCI-H295R and MUC1 cell lines to palbociclib and found a concentration- and time-dependent reduction of cell viability, which was more pronounced in the NCI-H295R cells in line with higher CDK4 expression. Furthermore, we tested palbociclib in combination with insulin-like growth factor 1/insulin receptor inhibitor linsitinib showing an additive effect. In conclusion, we demonstrate that RNA profiling is useful to discover potential drug targets and that CDK4/6 inhibitors are promising candidates for treatment of selected patients with ACC.

National Treatment Practice for Adrenocortical Carcinoma: Have They Changed and Have We Made Any Progress?

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare malignancy with a dismal prognosis. Two landmark trials published in 2007 and 2012 showed efficacy for adjuvant mitotane in resectable ACC and etoposide/doxorubicin/cisplatin plus mitotane for unresectable ACC, respectively. In this study, we used the National Cancer Database to examine whether treatment patterns and outcomes changed after these trials.

METHODS

The National Cancer Database was used to examine treatment patterns and survival in patients diagnosed with ACC from 2006 to 2015. Treatment modalities were compared within that group and with a historical cohort (1985 to 2005). χ2 tests were performed, and Cox proportional hazards models were created.

RESULTS

From 2006 to 2015, 2752 patients were included; 38% of patients (1042) underwent surgery alone, and 31% (859) underwent surgery with adjuvant therapy. Overall 5-year survival rates for all stages after resection were 43% (median, 41 months) in the contemporary cohort and 39% (median, 32 months) in the historical cohort. After 2007, patients who underwent surgery were more likely to receive adjuvant chemotherapy (P = 0.005), and 5-year survival with adjuvant chemotherapy improved (41% vs 25%; P = 0.02). However, survival did not improve in patients with unresectable tumors after 2011 compared with 2006 to 2011 (P = 0.79). Older age, tumor size ≥10 cm, distant metastases, and positive margins were associated with lower survival after resection (hazard ratio range: 1.39 to 3.09; P < 0.03).

CONCLUSIONS

Since 2007, adjuvant therapy has been used more frequently in patients with resected ACC, and survival for these patients has improved but remains low. More effective systemic therapies for patients with ACC, especially those in advanced stages, are desperately needed.

Targeting PDZ-binding kinase is anti-tumorigenic in novel preclinical models of ACC

Adrenocortical carcinoma (ACC) is an aggressive orphan malignancy with less than 35% 5-year survival and 75% recurrence. Surgery remains the primary therapy and mitotane, an adrenolytic, is the only FDA-approved drug with wide-range toxicities and poor tolerability. There are no targeted agents available to date. For the last three decades, H295R cell line and its xenograft were the only available preclinical models. We recently developed two new ACC patient-derived xenograft mouse models and corresponding cell lines (CU-ACC1 and CU-ACC2) to advance research in the field. Here, we have utilized these novel models along with H295R cells to establish the mitotic PDZ-binding kinase (PBK) as a promising therapeutic target. PBK is overexpressed in ACC samples and correlates with poor survival. We show that PBK is regulated by FOXM1 and targeting PBK via shRNA decreased cell proliferation, clonogenicity and anchorage-independent growth in ACC cell lines. PBK silencing inhibited pAkt, pp38MAPK and pHistone H3 altering the cell cycle. Therapeutically, targeting PBK with the small-molecule inhibitor HITOPK032 phenocopied PBK-specific modulation of pAkt and pHistone H3, but also induced apoptosis via activation of JNK. Consistent with in vitro findings, treatment of CU-ACC1 PDXs with HITOPK032 significantly reduced tumor growth by 5-fold (P < 0.01). Treated tumor tissues demonstrated increased rates of apoptosis and JNK activation, with decreased pAkt and Histone H3 phosphorylation, consistent with effects observed in ACC cell lines. Together these studies elucidate the mechanism of PBK in ACC tumorigenesis and establish the potential therapeutic potential of HITOPK032 in ACC patients.

Treatment of Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. ACC is capable of secreting excess adrenocortical hormones, which can compound morbidity and compromise clinical outcomes. By the time most ACCs are diagnosed, there is usually locoregional or metastatic disease. Surgery is the most important treatment to offer possibility of cure or prolong survival. Several adjuvant therapies are used depending on grade and stage of the tumor and other patient-related factors. This review provides an overview of treatment approaches for ACC, highlighting evidence to support each treatment and acknowledging where more data and research are needed to improve care.

Metastatic Adrenal Cortical Carcinoma Responding to Octreotide: A Case Report

Advanced adrenocortical carcinoma (ACC) is an aggressive disease with poor prognosis, and the current therapeutic options, such as mitotane or platinum-based chemotherapy regimens, often offer limited efficacy. Here, we present the first report, to the author's knowledge, of metastatic ACC with positive octreoscan scintigraphy that was successfully treated with octreotide long-acting release (LAR). A patient with metastatic ACC who showed poor tolerance to mitotane received octreotide LAR because of positive octreoscan scintigraphy. She obtained major partial response to the somatostatin analog. Interestingly, the expression of somatostatin receptor 2 from the previous local recurrence lesion was negative. The next-generation sequencing-based circulating tumor DNA analysis in the patient was performed and failed to identify any alterations. These findings suggest that octreotide LAR may be a good option for the treatment of metastatic ACC in selected patients.

microRNA-431 as a Chemosensitizer and Potentiator of Drug Activity in Adrenocortical Carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare endocrine cancer with treatments limited in efficacy for metastatic disease. New molecular targeted therapies have yet to improve patient outcomes. In contrast, established treatment regimens of adrenolytics and chemotherapy have demonstrated treatment benefit, although admittedly in a minority of patients. Identification of microRNAs (miRNAs) in patients responsive to adjuvant therapy may offer a means to sensitize patients with progressive disease to existing adjuvant regimens.

MATERIALS AND METHODS

Samples from primary ACC tumors of 10 Stage IV patients were examined for differentially expressed miRNAs between a "sensitive" and "resistant" cohort. Candidate microRNAs were restored via transfection in two functional ACC cell lines. Gain of function and effects on apoptosis and cell cycle were assessed.

RESULTS

microRNA-431 (miR-431) was underexpressed in patients with ACC with progressive disease undergoing adjuvant therapy. Restoration of miR-431 in vitro decreased the half maximal inhibitory concentrations of doxorubicin and mitotane, with markedly increased apoptosis. We found that a reversal of epithelial-mesenchymal transition underlies the action of miR-431 with doxorubicin treatment, with Zinc Finger E-Box Binding Homeobox 1 implicated as the molecular target of miR-431 in ACC.

CONCLUSION

This is the first report of the potential of miRNA therapy to sensitize ACC to current established adjuvant therapy regimens, which may mitigate the resistance underlying treatment failure in patients with advanced ACC. Effective and well-studied methods of targeted miRNA delivery in existence hints at the imminent translatability of these findings.

IMPLICATIONS FOR PRACTICE

Adrenocortical carcinoma (ACC) is a rare endocrine cancer with outcomes not improving despite extensive research and new targeted therapies. Mitotane and etoposide/doxorubicin/cisplatin chemotherapy is trial validated for improved recurrence-free survival. However, a minority of patients experience sustained benefit. Significant side effects exist for this regimen, with patients often unable to attain target drug doses shown to give survival benefit. This preclinical study examines the role of microRNAs in sensitizing ACC to doxorubicin or mitotane. This study offers an important bridge between new and existing cancer treatments, offering an imminently translatable approach to the treatment of adrenocortical carcinoma.

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.

Avelumab in patients with previously treated metastatic adrenocortical carcinoma: phase 1b results from the JAVELIN solid tumor trial

Background

We assessed the efficacy and safety of avelumab, an anti-programmed death ligand 1 (PD-L1) antibody, in patients with previously treated metastatic adrenocortical carcinoma (mACC).

Methods

In this phase 1b expansion cohort, patients with mACC and prior platinum-based therapy received avelumab at 10 mg/kg intravenously every 2 weeks. Continuation of mitotane was permitted; however, mitotane levels during the study were not recorded. Tumor response was assessed by Response Evaluation Criteria In Solid Tumors v1.1.

Results

Fifty patients received avelumab and were followed for a median of 16.5 months. Prior treatment included ≥2 lines in 74.0%; mitotane was continued in 50.0%. The objective response rate (ORR) was 6.0% (95% CI, 1.3% to 16.5%; partial response in 3 patients). Twenty-one patients (42.0%) had stable disease as best response (disease control rate, 48.0%). Median progression-free survival was 2.6 months (95% CI, 1.4 to 4.0), median overall survival (OS) was 10.6 months (95% CI, 7.4 to 15.0), and the 1-year OS rate was 43.4% (95% CI, 27.9% to 57.9%). In evaluable patients with PD-L1+ (n = 12) or PD-L1− (n = 30) tumors (≥5% tumor cell cutoff), ORR was 16.7% vs 3.3% (P = .192). Treatment-related adverse events (TRAEs) occurred in 82.0%; the most common were nausea (20.0%), fatigue (18.0%), hypothyroidism (14.0%), and pyrexia (14.0%). Grade 3 TRAEs occurred in 16.0%; no grade 4 to 5 TRAEs occurred. Twelve patients (24.0%) had an immune-related TRAE of any grade, which were grade 3 in 2 patients (4.0%): adrenal insufficiency (n = 1), and pneumonitis (n = 1).

Conclusions

Avelumab showed clinical activity and a manageable safety profile in patients with platinum-treated mACC.

Trial registration

Clinicaltrials.gov NCT01772004; registered January 21, 2013.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0424-9) contains supplementary material, which is available to authorized users.

European Society of Endocrinology Clinical Practice Guidelines on the management of adrenocortical carcinoma in adults, in collaboration with the European Network for the Study of Adrenal Tumors

Adrenocortical carcinoma (ACC) is a rare and in most cases steroid hormone-producing tumor with variable prognosis. The purpose of these guidelines is to provide clinicians with best possible evidence-based recommendations for clinical management of patients with ACC based on the GRADE (Grading of Recommendations Assessment, Development and Evaluation) system. We predefined four main clinical questions, which we judged as particularly important for the management of ACC patients and performed systematic literature searches: (A) What is needed to diagnose an ACC by histopathology? (B) Which are the best prognostic markers in ACC? (C) Is adjuvant therapy able to prevent recurrent disease or reduce mortality after radical resection? (D) What is the best treatment option for macroscopically incompletely resected, recurrent or metastatic disease? Other relevant questions were discussed within the group. Selected Recommendations: (i) We recommend that all patients with suspected and proven ACC are discussed in a multidisciplinary expert team meeting. (ii) We recommend that every patient with (suspected) ACC should undergo careful clinical assessment, detailed endocrine work-up to identify autonomous hormone excess and adrenal-focused imaging. (iii) We recommend that adrenal surgery for (suspected) ACC should be performed only by surgeons experienced in adrenal and oncological surgery aiming at a complete en bloc resection (including resection of oligo-metastatic disease). (iv) We suggest that all suspected ACC should be reviewed by an expert adrenal pathologist using the Weiss score and providing Ki67 index. (v) We suggest adjuvant mitotane treatment in patients after radical surgery that have a perceived high risk of recurrence (ENSAT stage III, or R1 resection, or Ki67 >10%). (vi) For advanced ACC not amenable to complete surgical resection, local therapeutic measures (e.g. radiation therapy, radiofrequency ablation, chemoembolization) are of particular value. However, we suggest against the routine use of adrenal surgery in case of widespread metastatic disease. In these patients, we recommend either mitotane monotherapy or mitotane, etoposide, doxorubicin and cisplatin depending on prognostic parameters. In selected patients with a good response, surgery may be subsequently considered. (vii) In patients with recurrent disease and a disease-free interval of at least 12 months, in whom a complete resection/ablation seems feasible, we recommend surgery or alternatively other local therapies. Furthermore, we offer detailed recommendations about the management of mitotane treatment and other supportive therapies. Finally, we suggest directions for future research.

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.

Elucidating the Role of the Maternal Embryonic Leucine Zipper Kinase in Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is an aggressive cancer with a 5-year survival rate <35%. Mortality remains high due to lack of targeted therapies. Using bioinformatic analyses, we identified maternal embryonic leucine zipper kinase (MELK) as 4.1-fold overexpressed in ACC compared with normal adrenal samples. High MELK expression in human tumors correlated with shorter survival and with increased expression of genes involved in cell division and growth. We investigated the functional effects of MELK inhibition using newly developed ACC cell lines with variable MELK expression, CU-ACC1 and CU-ACC2, compared with H295R cells. In vitro treatment with the MELK inhibitor, OTSSP167, resulted in a dose-dependent decrease in rates of cell proliferation, colony formation, and cell survival, with relative sensitivity of each ACC cell line based upon the level of MELK overexpression. To confirm a MELK-specific antitumorigenic effect, MELK was inhibited in H295R cells via multiple short hairpin RNAs. MELK silencing resulted in 1.9-fold decrease in proliferation, and 3- to 10-fold decrease in colony formation in soft agar and clonogenicity assays, respectively. In addition, although MELK silencing had no effect on survival in normoxia, exposure to a hypoxia resulted in a sixfold and eightfold increase in apoptosis as assessed by caspase-3 activation and TUNEL, respectively. Together these data suggest that MELK is a modulator of tumor cell growth and survival in a hypoxic microenvironment in adrenal cancer cells and support future investigation of its role as a therapeutic kinase target in patients with ACC.

The role of epithelial growth factors and insulin growth factors in the adrenal neoplasms

Human fetal and adult adrenal gland express both insulin growth factor-1 (IGF-1) and IGF-2, their receptors (IGF-Rs) and a variety of specific IGF binding proteins suggesting their potential role in the regulation of adrenal growth and function. IGF-2 overexpression is essential for the growth of monoclonal lesions, such as large benign adenomas (ACA) and adrenocortical carcinomas (ACC) and has been found to contribute to tumorigenesis in Beckwith-Wiedemann syndrome. IGF-2 is the most highly expressed gene observed in more than 85% of ACCs. However, no significant differences in clinical, biological and transcriptomic traits were found between tumors with high and low expression of IGF-2. On the contrary, the expression of IGF-1R, mediating the IGF-2 effects in vivo, was more discriminant between malignant (overexpression) and benign tumors. Data on the role of epithelial growth factor (EGF) and its receptor (EGF-R) in adrenocortical tumorigenesis are controversial. Several studies have shown EGF-R overexpression in ACCs but not in benign ACAs, suggesting that EGF-R could potentially be used as a marker for the differential diagnosis of ACAs and ACCs. Although, in vitro and animal studies provide promising results in the therapeutic role of IGF and EGF pathway inhibitors, the available data in humans are still not encouraging. Herein, we aim to present recent data on the role of IGF and EGF pathways in adrenal development and tumorigenesis and their potential implication in the treatment of the ACC, a rare malignancy with very poor prognosis.

New targeted therapies for adrenocortical carcinomas

Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis. It has undergone in-depth clinical and laboratory investigations, with the help of the most important research groups all over the world. Nonetheless the cure for this kind of neoplasia is not right around the corner, given its complexity and multi-faceted feature, that lead researchers to think at "one person one ACC." Currently total resection is the most concrete option for ACC patients, whenever possible. Mitotane remains the main drug for primary or adjuvant therapy, but gives partial and unsatisfactory therapeutic results, especially in metastatic ACC. This prompted the researchers to find other ways to fight against this malignancy: targeted therapy seems the most promising answer, as it is based on biomolecular and genetic cancer signature. Numerous specific targets were explored for the treatment of ACC, such as those involving angiogenesis, steroidogenesis, Wnt/β-catenin pathway and many others key factors. Even if large efforts have been made, no effective target therapy entered in the clinical use. This data should not be considered only as detrimental, rather it should propel scientific research to invest more resources into the therapeutic exploration of ACC and in particular on the most promising strategy, the targeted therapy.

Development of new preclinical models to advance adrenocortical carcinoma research

Adrenocortical cancer (ACC) is an orphan malignancy that results in heterogeneous clinical phenotypes and molecular genotypes. There are no curative treatments for this deadly cancer with 35% survival at five years. Our understanding of the underlying pathobiology and our ability to test novel therapeutic targets has been limited due to the lack of preclinical models. Here, we report the establishment of two new ACC cell lines and corresponding patient-derived xenograft (PDX) models. CU-ACC1 cell line and PDX were derived from a perinephric metastasis in a patient whose primary tumor secreted aldosterone. CU-ACC2 cell line and PDX were derived from a liver metastasis in a patient with Lynch syndrome. Short tandem repeat profiling confirmed consistent matches between human samples and models. Both exomic and RNA sequencing profiling were performed on the patient samples and the models, and hormonal secretion was evaluated in the new cell lines. RNA sequencing and immunohistochemistry confirmed the expression of adrenal cortex markers in the PDXs and human tumors. The new cell lines replicate two of the known genetic models of ACC. CU-ACC1 cells had a mutation in CTNNB1 and secreted cortisol but not aldosterone. CU-ACC2 cells had a TP53 mutation and loss of MSH2 consistent with the patient's known germline mutation causing Lynch syndrome. Both cell lines can be transfected and transduced with similar growth rates. These new preclinical models of ACC significantly advance the field by allowing investigation of underlying molecular mechanisms of ACC and the ability to test patient-specific therapeutic targets.

The challenge of developmental therapeutics for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare disease with an estimated incidence of only 0.7 new cases per million per year. Approximately 30-70% of the patients present with advanced disease with very poor prognosis and without effective therapeutic options. In the recent years, unprecedented progresses in cancer biology and genomics have fostered the development of numerous targeted therapies for various malignancies. Immunotherapy has also transformed the treatment landscape of malignancies such as melanoma, among others. However, these advances have not brought meaningful benefits for patients with ACC. Extensive genomic analyses of ACC have revealed numerous signal transduction pathway aberrations (e.g., insulin growth factor receptor and Wnt/β-catenin pathways) that play a central role in pathophysiology. These molecular alterations have been explored as potential therapeutic targets for drug development. This manuscript summarizes recent discoveries in ACC biology, reviews the results of early clinical studies with targeted therapies, and provides the rationale for emerging treatment strategies such as immunotherapy.

Adrenocortical Cancer: A Molecularly Complex Disease Where Surgery Matters

The development of new therapies has lagged behind for rare cancers without defined therapeutic targets. Adrenocortical cancer is no exception. Mitotane, an older agent considered "adrenolytic," is used both to control symptoms in advanced disease and as adjuvant therapy after surgical resection. Molecular characterization of adrenocortical cancer has deepened our understanding of this genetically complex disease while identifying subgroups whose importance remains to be determined. Unfortunately, such studies have yet to demonstrate a therapeutic target for drug development, and to date, no targeted therapy has achieved meaningful outcomes. Consequently, first-line therapy for metastatic disease remains a combination regimen of etoposide, doxorubicin, and cisplatinum established in a randomized clinical trial. In addition to evaluating recent studies in adrenocortical cancer, we raise one critical clinical issue-the risk of peritoneal dissemination following laparoscopic resection of adrenocortical cancer. In a retrospective case series of 267 patients referred to the NCI for the treatment of recurrent or advanced adrenocortical cancer, we found extensive peritoneal dissemination in 25 of the 45 patients (55.6%) who had undergone laparoscopic resection, compared with only 7 of the 222 patients (3%) who had undergone an open resection (P < 0.0001). Although this has been debated in the literature, our data argue for an end to laparoscopic resection of adrenocortical cancers to avoid peritoneal dissemination, a complication of laparoscopy that is uniformly fatal. Clin Cancer Res; 22(20); 4989-5000. ©2016 AACR SEE ALL ARTICLES IN THIS CCR FOCUS SECTION, "ENDOCRINE CANCERS REVISING PARADIGMS".

Co-inhibition of EGFR and IGF1R synergistically impacts therapeutically on adrenocortical carcinoma

Purpose

Adrenocortical carcinoma (ACC) is a rare tumor with very poor prognosis and no effective treatment. The aim of this study was to explore a novel therapy co-targeting EGFR and IGF1R in vitro and vivo.

Methods

The expression of EGFR and IGF1R were evaluated in a series of adrenocortical tumors by immunohistochemistry. Cell viability of ACC cell lines H295R and SW13 were determined by MTT assay after treatment with the combination of EGFR inhibitor Erlotinib and IGF1R inhibitor NVP-AEW541. Apoptosis was assessed by flow cytometry. The mechanism within intracellular signaling pathways was analyzed by Western blot. Mice bearing human ACC xenografts were treated with Erlotinib and NVP-AEW541, and the effects on tumour growth were assessed.

Results

Our results show a significant over-expression of EGFR (66.67%) and IGF1R (80.0%) in ACC. Besides, the co-overexpression of EGFR and IGF1R was seen in 8/15 ACCs, as compared with ACAs (P<0.05). Erlotinib and NVP-AEW541 significantly inhibited cell viability and induced apoptosis by blocking phosphorylation of MEK/ERK and AKT, respectively. Meanwhile, we found that single inhibition of IGF1R induced compensatory activation of MEK/ERK, leading to sustained activation of mTOR, which represent as aggregation of EGFR and IGF1R downstream components. More importantly, the combination of Erlotinib and NVP-AEW541 enhances anti-tumour efficacy compared to treatment with either agent alone or to untreated control in vitro and vivo.

Conclusions

In conclusion, coinhibition therapy targeting EGFR and IGF1R may be considerable for treatment of ACC in the future.

Gemcitabine-Based Chemotherapy in Adrenocortical Carcinoma: A Multicenter Study of Efficacy and Predictive Factors

CONTEXT

Adrenocortical carcinoma (ACC) is rare and confers an unfavorable prognosis in advanced stages. Other than combination chemotherapy with cisplatin, etoposide, doxorubicin, and mitotane, the second- and third-line regimens are not well-established. Gemcitabine (GEM)-based chemotherapy was suggested in a phase 2 clinical trial with 28 patients. In other solid tumors, human equilibrative nucleoside transporter type 1 (hENT1) and/or ribonucleotide reductase catalytic subunit M1 (RRM1) expression have been associated with resistance to GEM.

OBJECTIVE

To assess the efficacy of GEM-based chemotherapy in ACC in a real-world setting and the predictive role of molecular parameters.

DESIGN

Retrospective multicenter study.

SETTING

Referral centers of university hospitals.

PATIENTS AND MATERIALS

A total of 145 patients with advanced ACC were treated with GEM-based chemotherapy (132 with concomitant capecitabine). Formalin-fixed paraffin-embedded tumor material was available for 70 patients for immunohistochemistry.

OUTCOME MEASURES

The main outcome measures were progression-free survival (PFS) and an objective response to GEM-based chemotherapy. The secondary objective was the predictive role of hENT1 and RRM1.

RESULTS

The median PFS for the patient population was 12 weeks (range, 1 to 94). A partial response or stable disease was achieved in 4.9% and 25.0% of cases, with a median duration of 26.8 weeks. Treatment was generally well tolerated, with adverse events of grade 3 or 4 occurring in 11.0% of cases. No substantial effect of hENT1 and/or RRM1 expression was observed in response to GEM-based chemotherapy.

CONCLUSIONS

GEM-based chemotherapy is a well-tolerated, but modestly active, regimen against advanced ACC. No reliable molecular predictive factors could be identified. Owing to the scarce alternative therapeutic options, GEM-based chemotherapy remains an important option for salvage treatment for advanced ACC.

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.

Update on adrenocortical carcinoma management and future directions

PURPOSE OF REVIEW

To present an update on the management of and future directions in adrenocortical carcinoma (ACC).

RECENT FINDINGS

ACC is a rare malignancy with high morbidity and mortality. Surgery remains the mainstay treatment for localized disease, but it is often not feasible in more advanced cases. There is an ongoing controversy about the routine use of adjuvant treatments after surgery. Hormonal overproduction can complicate the management and worsen the prognosis of the disease. Systemic therapy with multiple cytotoxic drugs is often combined with the adrenolytic agent mitotane. Genomic analyses of ACC revealed numerous signal transduction pathway aberrations (insulin-like growth factor 2 overexpression, TP53 mutations and Wnt/β-catenin pathway activation), but so far, there has been no clinically meaningful breakthrough in targeting these genes. Immunotherapy offers hope for altering the orthodox management of cancer, and its role in ACC is being explored in multiple ongoing trials.

SUMMARY

Surgery by experienced team is the key treatment for localized ACC, whereas currently used chemotherapy has limited efficacy in advanced ACC. The improved understanding of the molecular pathways involved in ACC has not been translated into effective therapy. The development of new therapies requires collaborative effort to fight this disease.

New insights and future perspectives in the therapeutic strategy of adrenocortical carcinoma (Review)

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with an incidence ranging from 0.7 to 2.0 cases/million people per year. Hypercortisolism represents the most common clinical presentation in many patients although, less frequently, some ACC secreting androgens and estrogens are even more pathognomonic compared to cortisol secretion. Currently, radical surgery, when feasible, is still the only curative therapy. Mitotane, an adrenolytic drug, is used in the adjuvant setting and in combination with chemotherapy drugs in metastatic disease. The use of radiotherapy remains controversial, being indicated only in selected cases. New targeted therapies, such as insulin growth factor-1 (IGF-1), mammalian-target of rapamycin (m-TOR), vascular endothelial growth factor (VEGF) inhibitors and others, have recently been investigated with disappointing clinical results. The partial effectiveness of current treatments mandates the need for new therapeutic strategies against this tumor.

Novel targeted therapies in adrenocortical carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma is a rare cancer, but one that carries a poor prognosis due to its aggressive nature and unresponsiveness to conventional chemotherapeutic strategies. Over the past 12 years, there has been renewed interest in developing new therapies for this cancer, including identifying key signaling nodes responsible for cell proliferation.

RECENT FINDINGS

Clinical trials of tyrosine kinase inhibitors as monotherapy have generally been disappointing, although the identification of exceptional responders may lead to the identification of targeted therapies that may produce responses in subsets of patients. Agents targeted to the Wnt signaling pathway, a known player in adrenal carcinogenesis, have been developed, although they have not yet been used specifically for adrenal cancer. There is current excitement about inhibitors of acetyl-coA cholesterol acetyl transferase 1, an enzyme required for intracellular cholesterol handling, although trials are still underway. Tools to target other proteins such as Steroidogenic Factor 1 and mechanistic target of rapamycin have been developed and are moving towards clinical application.

SUMMARY

Progress is being made in the fight against adrenocortical carcinoma with the identification of new therapeutic targets and new means by which to attack them. Continued improvement in the prognosis for patients with adrenal cancer is expected as this research continues.

ATR-101 disrupts mitochondrial functions in adrenocortical carcinoma cells and in vivo

Adrenocortical carcinoma (ACC) generally has poor prognosis. Existing treatments provide limited benefit for most patients with locally advanced or metastatic tumors. We investigated the mechanisms for the cytotoxicity, xenograft suppression, and adrenalytic activity of ATR-101 (PD132301-02), a prospective agent for ACC treatment. Oral administration of ATR-101 inhibited the establishment and impeded the growth of ACC-derived H295R cell xenografts in mice. ATR-101 induced H295R cell apoptosis in culture and in xenografts. ATR-101 caused mitochondrial hyperpolarization, reactive oxygen release, and ATP depletion within hours after exposure, followed by cytochrome c release, caspase-3/7 activation, and membrane permeabilization. The increase in mitochondrial membrane potential occurred concurrently with the decrease in cellular ATP levels. When combined with ATR-101, lipophilic free radical scavengers suppressed the reactive oxygen release, and glycolytic precursors prevented the ATP depletion, abrogating ATR-101 cytotoxicity. ATR-101 directly inhibited F1F0-ATPase activity and suppressed ATP synthesis in mitochondrial fractions. ATR-101 administration to guinea pigs caused oxidized lipofuscin accumulation in the zona fasciculate layer of the adrenal cortex, implicating reactive oxygen release in the adrenalytic effect of ATR-101. These results support the development of ATR-101 and other adrenalytic compounds for the treatment of ACC.

Loss of β-catenin in adrenocortical cancer cells causes growth inhibition and reversal of epithelial-to-mesenchymal transition

Adrenal carcinoma (ACC) is a rare neoplasm with a poor outcome. Aberrant expression of β-catenin has been found in approximatively 30% of ACC. We herein studied its effects on the growth of the human ACC cell line H295R. The cells were infected with short hairpin RNA (shRNA)-mediated silencing β-catenin. Two shRNAs used induced down-regulation of β-catenin protein levels. The expression of these shRNAs decreased cell growth and increased H295R cells in S and G₂/M phases. This cytostatic effect is due to a decrease of phosphorylated MAPK and to an up-regulation expression of the cyclin-dependent kinase inhibitors p57^KIP2, p21^CIP and p27^KIP1. In addition, the knockdown of β-catenin decreased phosphorylated Akt and increased apoptosis. Finally, loss of β-catenin was sufficient to induce the reversal of the epithelial-to-mesenchymal transition. We then transplanted these genetically modified H295R cells in Scid mice. Tumor growth suppression was achieved by the two shRNAs showing in vitro efficacy. Proliferation was not reduced in silenced tumors. In contrast, p57, p27 and p21 proteins were found expressed at high levels in silenced tumors along with an increase in apoptotic cells. These findings indicate that β-catenin loss in H295R cells inhibits tumor growth by inducing transcriptional and functional changes.

5th International ACC Symposium: Future and Current Therapeutic Trials in Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare and complex disease associated with a high mortality rate. Despite intensive translational and clinical research, prognosis remains poor. Over the past decade, a significant effort has been made to develop multinational, collaborative studies to better understand the pathogenesis and clinical features of this rare disease in attempt to improve the therapeutic strategies and patient outcome. The results of both standard and newer treatments are discussed in this review as well as the recent discovery of pathways involved in ACC pathogenesis that provide the rationale to introduce new molecular target therapies. Finally, remaining issues regarding how to improve available therapies in adjuvant setting are raised and addressed.