Mitotane Monotherapy in Patients With Advanced Adrenocortical Carcinoma

Systemic Management of Advanced Adrenocortical Carcinoma

OPINION STATEMENT

Adrenocortical cancer (ACC) is a rare and aggressive disease. Surgery has traditionally been the primary treatment for locally advanced disease with ongoing controversy around the optimal neoadjuvant and adjuvant treatment options. Unfortunately, local recurrence and the eventual development of metastatic disease is common and five-year survival rates are poor. While many trials have evaluated novel systemic agents to treat advanced adrenocortical cancer, only a few drugs have demonstrated any response at all. To date, only one drug, mitotane, is approved in the US for ACC and no regimen has clearly shown an increase in overall survival. In advanced metastatic or unresectable disease, data supports the first line regimen of EDP chemotherapy + mitotane as the primary treatment modality. In the second line, while data is limited, we would recommend consideration of immunotherapy using a PD(L)1 agent combined with a TKI/VEGF inhibitor or combination immunotherapy with PD1/CTLA-4 drugs. In all cases, we always prefer a clinical trial as available. This article reviews data from multiple studies evaluating novel systemic agents against ACC and discusses current systemic therapy combinations and ongoing clinical trials.

Pharmacogenomic analysis in adrenocortical carcinoma reveals genetic features associated with mitotane sensitivity and potential therapeutics

Background

Adrenocortical carcinoma (ACC) is an aggressive endocrine malignancy with limited therapeutic options. Treating advanced ACC with mitotane, the cornerstone therapy, remains challenging, thus underscoring the significance to predict mitotane response prior to treatment and seek other effective therapeutic strategies.

Objective

We aimed to determine the efficacy of mitotane via an in vitro assay using patient-derived ACC cells (PDCs), identify molecular biomarkers associated with mitotane response and preliminarily explore potential agents for ACC.

Methods

In vitro mitotane sensitivity testing was performed in 17 PDCs and high-throughput screening against 40 compounds was conducted in 8 PDCs. Genetic features were evaluated in 9 samples using exomic and transcriptomic sequencing.

Results

PDCs exhibited variable sensitivity to mitotane treatment. The median cell viability inhibition rate was 48.4% (IQR: 39.3-59.3%) and -1.2% (IQR: -26.4-22.1%) in responders (n=8) and non-responders (n=9), respectively. Median IC50 and AUC were remarkably lower in responders (IC50: 53.4 µM vs 74.7 µM, P<0.0001; AUC: 158.0 vs 213.5, P<0.0001). Genomic analysis revealed CTNNB1 somatic alterations were only found in responders (3/5) while ZNRF3 alterations only in non-responders (3/4). Transcriptomic profiling found pathways associated with lipid metabolism were upregulated in responder tumors whilst CYP27A1 and ABCA1 expression were positively correlated to in vitro mitotane sensitivity. Furthermore, pharmacologic analysis identified that compounds including disulfiram, niclosamide and bortezomib exhibited efficacy against PDCs.

Conclusion

ACC PDCs could be useful for testing drug response, drug repurposing and guiding personalized therapies. Our results suggested response to mitotane might be associated with the dependency on lipid metabolism. CYP27A1 and ABCA1 expression could be predictive markers for mitotane response, and disulfiram, niclosamide and bortezomib could be potential therapeutics, both warranting further investigation.

Clinicopathological characteristics of adrenocortical carcinoma in the Kyushu-Okinawa area of Japan

OBJECTIVE

Adrenocortical carcinoma is a rare condition, with limited comprehensive reports from Japan. This study aimed to review Japan's data on adrenocortical carcinoma by assessing information from 46 patients-with adrenocortical carcinoma across 10 Japanese university hospitals.

METHODS

We conducted a retrospective multi-institutional analysis of the clinical characteristics of adrenocortical carcinoma in Japan. We evaluated data from 46 patients across 10 university hospitals over 10 years and analyzed the relationship between clinicopathological characteristics and overall survival.

RESULTS

Five- and 10-year overall survival rates were 59% and 53%, respectively. Overall survival was significantly different among the tumor-node-metastasis system for adrenocortical carcinoma of the American Joint Committee on Cancer/International Union Against Cancer, with the worst prognosis in stage IV (p = 0.0044). In our cohort, neither the Weiss score nor the Ki-67 proliferation index correlated with overall survival. Adjuvant treatment did not yield improved overall survival, whereas resection of the primary tumor in stage IV disease was significantly associated with improved overall survival (p = 0.0262). Out of the cases evaluated for plasma hormones, plasma cortisol, aldosterone, testosterone, and DHEA-S levels were measured at 23%, 42%, 29%, and 62%, respectively, demonstrating higher levels than the upper normal limits.

CONCLUSION

Patients with stage IV adrenocortical carcinoma had a poor prognosis; however, resection of the primary tumor in stage IV disease was associated with prolonged survival. The results of this study are expected to contribute to future treatment of adrenocortical carcinoma in Japan.

Current Status and Future Direction in the Treatment of Advanced Adrenocortical Carcinoma

PURPOSE OF REVIEW

To provide a comprehensive overview of the current understanding and developments in the treatment options for adrenocortical carcinoma (ACC), focusing on the strategies utilized for advanced disease.

RECENT FINDINGS

Research has delved into the genomic landscape of ACC, revealing potential targets for therapy. Despite the failure of inhibitors aimed at the insulin like growth factor 1(IGF-1) receptor, other approaches, including vascular endothelial growth factor receptor (VEFGR) tyrosine kinase inhibitors and immune checkpoint inhibitors, are being investigated. There are also ongoing trials of combination treatments such as lenvatinib with pembrolizumab and cabozantinib with atezolizumab. ACC remains a challenging malignancy with limited effective treatment options. Although EDP-M stands as the frontline treatment, the search for effective second-line therapies is ongoing. Targeted therapies and immunotherapies, especially in combination regimens, are demonstrating potential and are the subject of continued research. The evolving genomic landscape emphasizes the significance of targeted therapies and the need for further in-depth studies to solidify effective treatment regimens for ACC.

The Value of Local Therapies in Advanced Adrenocortical Carcinoma

International guidelines recommend local therapies (LTs) such as local thermal ablation (LTA; radiofrequency, microwave, cryoablation), transarterial (chemo)embolisation (TA(C)E), and transarterial radioembolisation (TARE) as therapeutic options for advanced adrenocortical carcinoma (ACC). However, the evidence for these recommendations is scarce. We retrospectively analysed patients receiving LTs for advanced ACC. Time to progression of the treated lesion (tTTP) was the primary endpoint. The secondary endpoints were best objective response, overall progression-free survival, overall survival, adverse events, and the establishment of predictive factors by multivariate Cox analyses. A total of 132 tumoural lesions in 66 patients were treated with LTA (n = 84), TA(C)E (n = 40), and TARE (n = 8). Complete response was achieved in 27 lesions (20.5%; all of them achieved by LTA), partial response in 27 (20.5%), and stable disease in 38 (28.8%). For the LTA group, the median tTTP was not reached, whereas it was reached 8.3 months after TA(C)E and 8.2 months after TARE (p < 0.001). The median time interval from primary diagnosis to LT was >47 months. Fewer than four prior therapies and mitotane plasma levels of >14 mg/L positively influenced the tTTP. In summary, this is one of the largest studies on LTs in advanced ACC, and it demonstrates a very high local disease control rate. Thus, it clearly supports the guideline recommendations for LTs in these patients.

Pulmonary Metastasectomy for Adrenocortical Carcinoma-Not If, but When

BACKGROUND

Adrenocortical carcinoma (ACC) commonly metastasizes to the lungs, and pulmonary metastasectomy (PM) is utilized due to limited systemic options.

METHODS

All ACC patients with initially only lung metastases (LM) from a single institution constituted this observational case series. Kaplan-Meier and Cox proportional hazard analyses evaluated the association with potential prognostic factors and outcomes. Overall survival (OS) was calculated from the date of the PM or, in those patients who did not undergo surgery, from the development of LM.

RESULTS

A total of 75 ACC patients over a 45-year period met the criteria; 52 underwent PM, and 23 did not. The patients undergoing PM had a median OS of 3.1 years (95% CI: 2.4, 4.7 years) with the 5- and 10-year OS being 35.5% and 32.8%, respectively. The total resected LM did not impact the OS nor the DFS. The patients who developed LM after 11 months from the initial ACC resection had an improved OS (4.2 years; 95% CI: 3.2, NR; p = 0.0096) compared to those developing metastases earlier (2.4 years; 95% CI: 1.6, 2.8). Patients who underwent PM within 11 months of adrenalectomy demonstrated a reduced OS (2.2 years; 95% CI: 1.0, 2.7) compared to those after 11 months (3.6 years, 95% CI: 2.6, NR; p = 0.0045). PM may provide benefit to those patients with LM at presentation (HR: 0.5; p = 0.2827), with the time to first PM as a time-varying covariate.

CONCLUSIONS

PM appears to have a role in ACC patients. The number of nodules should not be an exclusion factor. Patients developing LM within a year of primary tumor resection may benefit from waiting before further surgeries, which may provide additional insight into who may benefit from PM.

High-Dose Rate Brachytherapy Combined with PD-1 Blockade as a Treatment for Metastatic Adrenocortical Carcinoma - A Single Center Case Series

The response rate of advanced adrenocortical carcinoma (ACC) to standard chemotherapy with mitotane and etoposide/doxorubicin/cisplatin (EDP-M) is unsatisfactory, and benefit is frequently short lived. Immune checkpoint inhibitors (CPI) have been examined in patient's refractory to EDP-M, but objective response rates are only approximately 15%. High-dose rate brachytherapy (HDR-BT) is a catheter-based internal radiotherapy and expected to favorably combine with immunotherapies. Here we describe three cases of patients with advanced ACC who were treated with HDR-BT and the CPI pembrolizumab. None of the tumors were positive for established response markers to CPI. All patients were female, had progressed on EDP-M and received external beam radiation therapy for metastatic ACC. Pembrolizumab was initiated 7 or 23 months after brachytherapy in two cases and prior to brachytherapy in one case. Best response of lesions treated with brachytherapy was complete (n=2) or partial response (n=1) that was ongoing at last follow up after 23, 45 and 4 months, respectively. Considering all sites of tumor, response was complete and partial remission in the two patients with brachytherapy prior to pembrolizumab. The third patient developed progressive disease with severe Cushing's syndrome and died due to COVID-19. Immune-related adverse events of colitis (grade 3), gastroduodenitis (grade 3), pneumonitis (grade 2) and thyroiditis (grade 1) occurred in the two patients with systemic response. HDR-BT controlled metastases locally. Sequential combination with CPI therapy may enhance an abscopal antitumoral effect in non-irradiated metastases in ACC. Systematic studies are required to confirm this preliminary experience and to understand underlying mechanisms.

Impact of EDP-M on survival of patients with metastatic adrenocortical carcinoma: A population-based study

INTRODUCTION

Historically, stage IV adrenocortical carcinoma (mACC) has a poor prognosis with a median overall survival (OS) of only 5 months. Based on the FIRM-ACT trial published in 2012, guidelines now advise first line systemic treatment with etoposide, cisplatin, doxorubicin and mitotane (EDP-M). The effect of EDP-M on patient survival in clinical practice in the Netherlands is unknown.

METHODS

The data of all patients with mACC (2005-2020) were obtained from the Netherlands comprehensive cancer organization (IKNL). The effect of EDP-M on patient survival was assessed using Kaplan-Meier analysis and multivariate Cox regression analysis including clinical, therapy and tumor characteristics.

RESULTS

In total 167 patients with mACC were included. For patients diagnosed from 2014 onwards, EDP-M (in 22 patients (22%)) lead to a numerically but not statistically significant improved OS compared to those not receiving EDP-M (11.8 vs 5.6 months, p = 0.525). For systemic treatments, patients treated with mitotane only had the best 5-year OS (11.4%, p = 0.006) regardless of year of diagnosis. In multivariate Cox regression analysis EPD-M was not associated with OS; palliative adrenalectomy (HR: 0.26, p = <.001) and local treatment of metastases (HR: 0.35, p = 0.001) were associated with a better OS and a primary tumor Ki-67 index > 20% (HR: 2.67, p = 0.003) with a worse OS from 2014 onwards. Patients diagnosed before 2014 had a significantly poorer OS compared to from 2014 onwards (5-yr: 4.5 vs 8.4%, OS: 6.8 vs 8.3 months, p = 0.032).

CONCLUSION

OS for mACC in the Netherlands has improved in the last decade. Receiving EDP-M did not significantly improve OS for patients with mACC. The use of multimodality treatment including palliative adrenalectomy, mitotane and local treatment of (oligo-)metastases in appropriately selected patients has improved the OS for mACC patients since 2014.

Adrenocortical carcinoma: Diagnosis, prognostic classification and treatment of localized and advanced disease

Adrenocortical carcinoma (ACC) is a rare cancer with an estimated incidence of 0.7 to 2.0 cases per 1 million population per year in the United States. It is an aggressive cancer originating in the cortex of the adrenal gland with a poor prognosis. The 5-year survival rate is less than 15% among patients with metastatic disease. In this article, we review the epidemiology and pathogenesis of ACC, the diagnostic procedures, the prognostic classification of ACC, and the treatment options from localized and resectable forms to advanced disease detailing recent therapeutic developments such as immunotherapy and molecularly targeted therapy.

Case Report: Response to ipilimumab and nivolumab in a patient with adrenocortical carcinoma

Background

Adrenocortical carcinoma (ACC) is a rare malignancy with limited treatment options. The evidence for the use of immunotherapy in ACC has been conflicting, with overall response rates ranging from 6 - 33%.

Case presentation

We describe the case of a 32 year old patient who was initially thought to have an inoperable clear cell renal cell carcinoma and was treated with immunotherapy with ipilimumab and nivolumab. The patient had an excellent partial response to treatment. Further work-up prior to consideration of surgery demonstrated that the tumour was an ACC, rather than a renal cancer. She had a right adrenalectomy and right hepatectomy, achieving an R0 resection and remains disease-free one year after surgery.

Conclusion

This case illustrates the challenge of diagnosing ACC, and that doublet immunotherapy with ipilimumab and nivolumab can have significant clinical efficacy in ACC.

A Revised Version of the TNM Classification Leads to Optimized Predictive Performance in Patients with Adrenocortical Carcinoma

The prognostic stratification of the current AJCC/UICC TNM classification for adrenocortical carcinoma (ACC) has been validated in only a few studies. In this study, it was hypothesized that redefining the T category cut-off would result in a significant improvement in estimated stage-related survival. In 935 patients with ACC from the SEER database, optimal cut-off values based on tumor size were first determined to redefine T1 and T2 categories. Cox proportional hazards regression analysis and receiver operating characteristics (ROC) were then used to determine the prognostic value of the revised version. A new cut-off value of 9.5 cm tumor size was established to differentiate between T1 and T2 tumors, leading to a revised TNM classification. As a result, a more homogeneous distribution of patients with ACC across all stages was observed. Notably, the predictive value of the newly proposed TNM classification in the ROC analysis exceeded that of the 7th and 8th editions of the AJCC/UICC classification system. Finally, the prognostic superiority of the revised TNM classification was confirmed in a multivariate Cox proportional hazards regression model. In conclusion, the present study demonstrates that updating the current staging system with revised T1 and T2 categories significantly improves the prediction of cancer-specific survival (CSS) in patients with ACC.

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.

Vitamin D receptor activation is a feasible therapeutic target to impair adrenocortical tumorigenesis

OBJECTIVE

To evaluate the therapeutic potential of vitamin D receptor (VDR) signaling in adrenocortical carcinoma (ACC) cells.

METHODS

We evaluated VDR's methylation pattern in H295R ACC cells, and investigated the effects of calcitriol and seocalcitol treatments on adrenocortical tumorigenesis.

RESULTS

VDR was hypermethylated and underexpressed in basal H295R cells. Treatments with calcitriol and seocalcitol restored VDR signaling, resulted in antiproliferative effects, and impaired Wnt/B-catenin signaling. RNAseq of treated cells demonstrated VDR activation on steroid hormones biosynthesis and Rap1 signaling, among others. In vivo, seocalcitol constrained the growth of H295R xenografts and reduced autonomous tumor steroid secretion without hypercalcemia-associated side effects.

CONCLUSIONS

H295R cells present VDR hypermethylation, which can be responsible for its underexpression and signaling inactivation under basal conditions. VDR signaling promoted antiproliferative effects in vitro and in vivo, suggesting that it may be a potential therapeutic target for ACC and a valuable tool for patient's clinical management.

Advanced Adrenocortical Carcinoma: From Symptoms Control to Palliative Care

The prognosis of patients with advanced adrenocortical carcinoma (ACC) is often poor: in the case of metastatic disease, five-year survival is reduced. Advanced disease is not a non-curable disease and, in referral centers, the multidisciplinary approach is the standard of care: if a shared decision regarding several treatments is available, including the correct timing for the performance of each one, overall survival is increased. However, many patients with advanced ACC experience severe psychological and physical symptoms secondary to the disease and the cancer treatments. These symptoms, combined with existential issues, debase the quality of the remaining life. Recent strong evidence from cancer research supports the early integration of palliative care principles and skills into the advanced cancer patient's trajectory, even when asymptomatic. A patient with ACC risks quickly suffering from symptoms/effects alongside the disease; therefore, early palliative care, in some cases concurrent with oncological treatment (simultaneous care), is suggested. The aims of this paper are to review current, advanced ACC approaches, highlight appropriate forms of ACC symptom management and suggest when and how palliative care can be incorporated into the ACC standard of care.

Update on Biology and Genomics of Adrenocortical Carcinomas: Rationale for Emerging Therapies

The adrenal glands are paired endocrine organs that produce steroid hormones and catecholamines required for life. Adrenocortical carcinoma (ACC) is a rare and often fatal cancer of the peripheral domain of the gland, the adrenal cortex. Recent research in adrenal development, homeostasis, and disease have refined our understanding of the cellular and molecular programs controlling cortical growth and renewal, uncovering crucial clues into how physiologic programs are hijacked in early and late stages of malignant neoplasia. Alongside these studies, genome-wide approaches to examine adrenocortical tumors have transformed our understanding of ACC biology, and revealed that ACC is composed of distinct molecular subtypes associated with favorable, intermediate, and dismal clinical outcomes. The homogeneous transcriptional and epigenetic programs prevailing in each ACC subtype suggest likely susceptibility to any of a plethora of existing and novel targeted agents, with the caveat that therapeutic response may ultimately be limited by cancer cell plasticity. Despite enormous biomedical research advances in the last decade, the only potentially curative therapy for ACC to date is primary surgical resection, and up to 75% of patients will develop metastatic disease refractory to standard-of-care adjuvant mitotane and cytotoxic chemotherapy. A comprehensive, integrated, and current bench-to-bedside understanding of our field's investigations into adrenocortical physiology and neoplasia is crucial to developing novel clinical tools and approaches to equip the one-in-a-million patient fighting this devastating disease.

Bridging the Scientific Gaps to Identify Effective Treatments in Adrenocortical Cancer

Adrenocortical cancer (ACC) typically presents in advanced stages of disease and has a dismal prognosis. One of the foremost reasons for this is the lack of available systemic therapies, with mitotane remaining the backbone of treatment since its discovery in the 1960s, despite underwhelming efficacy. Surgery remains the only potentially curative option, but about half of patients will recur post-operatively, often with metastatic disease. Other local treatment options have been attempted but are only used practically on a case-by-case basis. Over the past few decades there have been significant advances in understanding the molecular background of ACC, but this has not yet translated to better treatment options. Attempts at novel treatment strategies have not provided significant clinical benefit. This paper reviews our current treatment options and molecular understanding of ACC and the reasons why a successful treatment has remained elusive. Additionally, we discuss the knowledge gaps that need to be overcome to bring us closer to successful treatment and ways to bridge them.

New endpoints in adrenocortical carcinoma studies: a mini review

PURPOSE

Adrenocortical carcinoma (ACC) is a very rare and aggressive malignant disease. Therefore, overall survival (OS) has long been considered as the best endpoint. Yet, a unique endpoint is not optimal to take into account the heterogeneity in tumor profile and the diversification of therapeutic option. The purpose of this mini review was to describe endpoints used in the past, present and future in the field of ACC.

METHODS

Pubmed and Clinicaltrial.gov were used to identify relevant studies.

RESULTS

Before year 2000 only three endpoints were regularly used: OS, recurrence-free survival (RFS) and response rate. These endpoints were used because ACC was seen as a homogeneous diseases with a high recurrence rate and low rate of long-term survival. Since 2000; along with the apparition of new class of drug, progression-free survival (PFS) has been more and more used. Other endpoints as "time to chemotherapy" or "Progression-free survival 2" were used to evaluate multimodal therapies or treatment with a delayed action. Finally, there is a hope that in the near future, quality of life along with other patient-reported outcomes may be used more frequently.

CONCLUSION

While OS and PFS are currently the most used endpoints in ACC, new endpoints are needed to better take into account the challenges offered by different situations and treatment strategies.

ENDOCRINE TUMOURS: Our experience with the management of patients with non-metastatic adrenocortical carcinoma

Adrenocortical carcinoma (ACC) accounts for a minority of all malignant tumors in adults. Surgery remains the most important therapeutic option for non-metastatic ACC. Whether a subset of patients with small ACC may benefit from minimally invasive surgery remains a debated issue, but we believe that surgeon's expertise is more important than surgical technique to determine outcome. However, even a state-of-the-art surgery cannot prevent disease recurrence that is determined mainly by specific tumor characteristics. We consider that the concomitant presence of the following features characterizes a cohort of patients at low risk of recurrence, (i) R0 resection (microscopically free margin), (ii) localized disease (stage I-II ACC), and (iii) low-grade tumor (ki-67 <10%). After the ADIUVO study, we do not recommend adjuvant mitotane as a routine measure for such patients, who can be managed with active surveillance thus sparing a toxic treatment. Patients at average risk of recurrence should be treated with adjuvant mitotane. For patients at very high risk of recurrence, defined as the presence of at least one of the following: Ki67 >30%, large venous tumor thrombus, R1 resection or stage IV ACC, we increasingly recommend to combine mitotane with four cycles of platinum-based chemotherapy. However, patients at moderate-to-high risk of recurrence should be ideally enrolled in the ongoing ADIUVO2 trial. We do not use adjuvant radiotherapy of the tumor bed frequently at our institutions, and we select patients with incomplete resection, either microscopically or macroscopically, for this treatment. In the long-term, prospective multicenter trials are required to improve patient care.

Sex-Based Evaluation of Lipid Profile in Postoperative Adjuvant Mitotane Treatment for Adrenocortical Carcinoma

Background: A wide interindividual variability in mitotane concentrations and treatment-related dyslipidemia have been reported. Here, we aimed to underline the sex-related differences in the lipid profile in patients that underwent radical surgery of adrenocortical carcinoma during treatment with adjuvant mitotane. Methods: A chromatographic method was used to quantify the drug in plasma collected from adult patients with complete tumor resection, also considering active metabolite o,p’-DDE. Results: We observed different lipid profiles between males and females and between pre- and post-menopausal women. Considering the mitotane-related effects on lipid levels, we observed that higher drug concentrations were correlated with higher HDL in all the considered groups (p < 0.001), with total cholesterol both in males (p = 0.005) and females (p = 0.036), with triglycerides in postmenopausal females (p = 0.002) and with LDL in male patients (p < 0.001). Increases in o,p’-DDE were positively correlated with HDL levels in all the groups (p < 0.001) and negatively with LDL in all the groups (males p = 0.008, pre- and post-menopausal females p < 0.001), with total cholesterol in pre- (p = 0.016) and post-menopausal women (p = 0.01) and with triglycerides in premenopausal females (p = 0.005). Conclusions: This is the first study designed to evaluate sex differences in lipoprotein and lipid levels during mitotane adjuvant treatment; the results suggest that a gender and personalized approach could be useful to prevent and manage alterations in the lipid profile.

Prognostic factors in advanced Adrenocortical Carcinoma: Summary of a national referral center’s 20 years of experience

Context

Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis for both locally advanced and metastatic disease. Standard treatment with combination etoposide–doxorubicin–cisplatin–mitotane (EDP-M) is highly toxic and some patients benefit from mitotane monotherapy. However, identification of these patients remains challenging.

Objective

We present a summary of the Israeli national referral center’s 20 years of experience in treating advanced ACC, with the aim of identifying prognostic factors and assisting in treatment decision making.

Methods

We conducted a retrospective multivariate analysis of patients treated for metastatic or locally advanced ACC at Hadassah Medical Center between 2000 and 2020 to determine clinical, pathological, and treatment factors correlated with overall survival (OS).

Results

In our cohort of 37 patients, a combination of modified European Network for the study of Adrenal Tumors (mENSAT) staging with either grade and R status, or age and symptoms was validated to stratify prognosis (P = .01 and P = .03, respectively). Patients who underwent R0 resection followed by radiotherapy or metastasectomy for oligometastatic disease had longer OS than patients with residual disease: median OS of 55 months vs 14 months, respectively, hazard ratio 3.1 (CI 1.4-6.7, P = .005). Patients treated with mitotane monotherapy had a significantly better prognosis, yet this result was attenuated in a multivariate analysis controlling for mENSAT and R status. Of patients treated with EDP-M, 41.4% experienced grade 3 or higher adverse events.

Conclusion

Patients with advanced ACC achieving R0 status have a better prognosis and might benefit from mitotane monotherapy.

Blood-Based Next-Generation Sequencing in Adrenocortical Carcinoma

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare and heterogeneous malignancy with poor prognosis. We aimed to evaluate the feasibility of next-generation sequencing (NGS) testing of circulating cell-free tumor DNA (ctDNA) in patients with ACC, to characterize the genomic landscape of alterations, and to identify potential clinically actionable mutations.

METHODS

Retrospective analysis of genomic data from 120 patients with ACC who had ctDNA testing between 12/2016 and 10/2021 using Guardant360 (Guardant Health, CA) was performed. ctDNA NGS analysis interrogated single nucleotide variants, fusions, indels, and copy number amplifications of up to 83 genes. The frequency of genomic alterations, landscape of co-occurring mutations, and pathogenic/likely pathogenic alterations with potential targeted therapies was identified. The prevalence of alterations identified in ctDNA was compared to those detected in tissue using a publicly available database (cBioPortal).

RESULTS

The median age of this cohort was 53 years (range 21-81), and 56% of patients were female. Ninety-six patients (80%) had ≥1 somatic alteration detected. TP53 (52%), EGFR (23%), CTNNB1 (18%), MET (18%), and ATM (14%) were found to be the most frequently altered genes in ACC samples. Pathogenic and/or likely pathogenic mutations in therapeutically relevant genes were observed in 56 patients (47%) and included EGFR, BRAF, MET, CDKN2A, CDK4/6, and ATM. The most frequent co-occurring mutations were EGFR + MET (9%), MET + CDK4 (7%), EGFR + CDK4 (7%), and BRAF + MET (7%). The frequencies of mutations detected in ctDNA were similar to those detected in tissue.

CONCLUSIONS

Utilizing blood-based NGS to characterize genomic alterations in advanced ACC is feasible in over 80% of patients. Almost half of the patients had actionable mutations with approved therapies in other cancers. This approach might inform the development of personalized treatment options or identify clinical trials available for this aggressive malignancy.

Vitamin D receptor hypermethylation as a biomarker for pediatric adrenocortical tumors

OBJECTIVE

Pediatric adrenocortical tumors (pACT) display complex genomic backgrounds, lacking robust prognostic markers and targeted therapeutic options. Vitamin D3 receptor (VDR) promoter hypermethylation and underexpression were reported in adrenocortical carcinomas from adult patients. In this study, we aimed to investigate VDR expression levels and methylation status in pACT and their clinical and prognostic significance.

DESIGN

Retrospective cross-sectional study enrolling pediatric patients with ACT from two tertiary referral institutions.

METHODS

We evaluated clinicopathological features, VDR mRNA (qPCR) and protein (immunohistochemistry) expression, and VDR-wide methylation of ACT samples from 108 pediatric patients. Fourteen pediatric and 32 fetal and postnatal normal adrenals were used as controls.

RESULTS

Unlike in pre- and post-natal normal adrenals, most pACT lacked nuclear VDR expression and had reduced mRNA levels, especially the carcinomas. Unsupervised analysis of VDR methylation data revealed two groups of pACT with distinct disease features and outcomes. Tumors with high VDR methylation presented lower mRNA levels, and the respective patients presented advanced disease and reduced disease-free and overall survival.

CONCLUSIONS

VDR has a role in normal adrenocortical development and homeostasis, which is impaired during tumorigenesis. VDR hypermethylation and underexpression may be both predictive and prognostic biomarkers for pACT.

Can Drug Repurposing be Effective Against Carbapenem-Resistant Acinetobacter baumannii?

Carbapenem-resistant Acinetobacter baumannii has been classified as a top priority for the development of new therapies due to its resistance to most antibiotics. Drug repurposing may be a fast and inexpensive strategy for treating this pathogen. This review aims to critically evaluate repurposed drugs for the treatment of infections caused by carbapenem-resistant A. baumannii, correlating their antimicrobial activity with data available for toxicity and side effects. Some drugs have been suggested as promising candidates for repurposing; however, in some cases, high toxicity and low plasma concentrations reduce applicability in clinical practice. The most favorable applicability is offered by fusidic acid and colistin, possibly combined with a third agent, promising to be well tolerated and achieving satisfactory plasma concentrations.

The challenge to differentiate between sarcoma or adrenal carcinoma—an observational study

Background

Adrenal sarcomas are rare malignant tumors with structural and clinical similarities to sarcomatoid adrenocortical carcinoma. Preoperative diagnosis of tumors of the adrenal gland can be challenging and often misleading thus detaining patients from appropriate oncological strategies.

Objective

This analysis of a case series evaluated the predictive capability of the primary clinical diagnosis in case of malignancies of the adrenal gland.

Methods

Thirty two patients were treated from 2009 to 2015 at our clinic and analyzed retrospectively. All patients had computed tomography and/or magnet resonance imaging and a primary histopathological examination at our institution after surgery. Ten questionable cases were surveyed by a reference pathologist.

Results

Twelve out of 32 diagnoses had to be revised (37.5%). Only 15 out of 24 tumors primarily classified as adrenocortical carcinoma were finally described as primary adrenal cancer. We found two leiomyosarcomas, one liposarcoma, one sarcomatoid adrenocortical carcinoma, and one epitheloid angiosarcoma among 12 misleading diagnoses. Other tumors turned out to be metastases of lung, hepatocellular, and neuroendocrine tumors. Larger tumors were significantly more often correctly diagnosed compared to smaller tumors. Four patients of the group of revised diagnoses died whereas all patients with confirmed diagnoses survived during the follow-up.

Conclusion

Preoperative assessment of tumors of the adrenal gland is still challenging. In case of wrong primary diagnosis, the prognosis could be impaired due to inadequate surgical procedures or insufficient preoperative oncological treatment.

Mitotane treatment in adrenocortical carcinoma: mechanisms of action and predictive markers of response to therapy

INTRODUCTION

Adrenocortical carcinoma (ACC) is a rare malignancy with a high risk of recurrence even in cases with complete surgical tumor resection. Mitotane represents the cornerstone of the adjuvant therapy as well as the first line of medical treatment in advanced cases. However, evidence on mitotane efficacy is mostly based on retrospective studies and the use of mitotane continues to represent a clinical challenge.

EVIDENCE ACQUISITION

Mitotane causes selective damage to adrenocortical cells, causing an increase of cell apoptosis through a disruption of mitochondria and the induction of the endoplasmic reticulum stress. Different clinical and molecular markers predicting response to mitotane have been proposed with uncertain results. Attainment of mitotane plasma levels within the target range of 14 to 20 mg/L represent the strongest predictor of mitotane effectiveness both in adjuvant and advanced tumor setting. The occurrence of late recurrence after primary ACC diagnosis and changes in metabolic activity on FDG-PET are only weakly associated with mitotane response. Among the proposed molecular markers associated with mitotane efficacy, the investigation of the CYP2W1*6 and CYP2B6*6 single nucleotide polymorphisms appears to be currently the most promising predictive molecular markers of mitotane therapy. However, none of the evaluated markers has been validated for clinical use.

CONCLUSIONS

In the era of precision medicine, a better insight into mitotane molecular mechanisms as well as the potential use in the daily clinical practice of clinical parameters and molecular markers predicting the individual response to mitotane are urgently needed.

Novel CYP11B-ligand [123/131I]IMAZA as promising theranostic tool for adrenocortical tumors: comprehensive preclinical characterization and first clinical experience

PURPOSE

Adrenal tumors represent a diagnostic and therapeutic challenge. Promising results have been obtained through targeting the cytochrome P450 enzymes CYP11B1 and CYP11B2 for molecular imaging, and [123/131I]iodometomidate ([123/131I]IMTO) has even been successfully introduced as a theranostic agent. As this radiopharmaceutical shows rapid metabolic inactivation, we aimed at developing new improved tracers.

METHODS

Several IMTO derivatives were newly designed by replacing the unstable methyl ester by different carboxylic esters or amides. The inhibition of aldosterone and cortisol synthesis was tested in different adrenocortical cell lines. The corresponding radiolabeled compounds were assessed regarding their stability, in vitro cell uptake, in vivo biodistribution in mice, and their binding specificity to cryosections of human adrenocortical and non-adrenocortical tissue. Furthermore, a first investigation was performed in patients with known metastatic adrenal cancer using both [123I]IMTO and the most promising compound (R)-1-[1-(4-[123I]iodophenyl)ethyl]-1H-imidazole-5-carboxylic acid azetidinylamide ([123I]IMAZA) for scintigraphy. Subsequently, a first endoradiotherapy with [131I]IMAZA in one of these patients was performed.

RESULTS

We identified three analogues to IMTO with high-affinity binding to the target enzymes and comparable or higher metabolic stability and very high and specific accumulation in adrenocortical cells in vitro and in vivo. Labeled IMAZA exhibited superior pharmacokinetic and imaging properties compared to IMTO in mice and 3 patients, too. An endoradiotherapy with [131I]IMAZA induced a 21-month progression-free interval in a patient with rapidly progressing ACC prior this therapy.

CONCLUSION

We developed the new radiopharmaceutical [123/131I]IMAZA with superior properties compared to the reference compound IMTO and promising first experiences in humans.

Tumor Doubling Time Using CT Volumetric Segmentation in Metastatic Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare malignancy with an overall unfavorable prognosis. Clinicians treating patients with ACC have noted accelerated growth in metastatic liver lesions that requires rapid intervention compared to other metastatic locations. This study measured and compared the growth rates of metastatic ACC lesions in the lungs, liver, and lymph nodes using volumetric segmentation. A total of 12 patients with metastatic ACC (six male; six female) were selected based on their medical history. Computer tomography (CT) exams were retrospectively reviewed and a sampling of ≤5 metastatic lesions per organ were selected for evaluation. Lesions in the liver, lung, and lymph nodes were measured and evaluated by volumetric segmentation. Statistical analyses were performed to compare the volumetric growth rates of the lesions in each organ system. In this cohort, 5/12 had liver lesions, 7/12 had lung lesions, and 5/12 had lymph node lesions. A total of 92 lesions were evaluated and segmented for lesion volumetry. The volume doubling time per organ system was 27 days in the liver, 90 days in the lungs, and 95 days in the lymph nodes. In this series of 12 patients with metastatic ACC, liver lesions showed a faster growth rate than lung or lymph node lesions.

Combination of Mitotane and Locoregional Treatments in Low-volume Metastatic Adrenocortical Carcinoma

CONTEXT

European and French guidelines for ENSAT stage IV low tumor burden or indolent adrenocortical carcinoma (ACC) recommend a combination of mitotane and locoregional treatments (LRT) as first-line treatment. Nevertheless, the benefit of LRT in combination with mitotane has never been evaluated in this selected group of patients.

OBJECTIVE

This work aimed to evaluate the therapeutic strategy of LRT combined with mitotane in patients with low tumor burden stage IVA ACC.

METHODS

A retrospective chart review was performed from 2003 to 2018 of patients with stage IV ACC with 2 or fewer tumoral organs who received mitotane in our center. The primary end point was the delay between mitotane initiation and first systemic chemotherapy. Secondary end points were progression-free survival (PFS) and overall survival (OS) from mitotane initiation. Adjusted analyses were performed on the main prognostic factors.

RESULTS

Out of 79 included patients, 48 (61%) patients were female and the median age at stage IVA diagnosis was 49.8 years (interquartile range [IQR], 38.8-60.0 years). Metastatic sites were mainly lungs (76%) and liver (48%). Fifty-eight (73%) patients received LRT including adrenal bed radiotherapy (14 patients, 18%), surgery (37 patients, 47%), and/or interventional radiology (35 patients, 44%). Median time between mitotane initiation and first chemotherapy administration was 9 months (IQR, 4-18 months). Median PFS1 (first tumor-progression) was 6.0 months (95% CI, 4.5-8.6). Median OS was 46 months (95% CI, 41-68). PFS1, PFS2, and OS were statistically longer in the mitotane plus LRT group compared to the mitotane-only group (hazard ratio [HR] = 0.39; 95% CI, 0.22-0.68; HR = 0.35; 95% CI, 0.20-0.63; and HR = 0.27; 95% CI, 0.14-0.50, respectively). Ten (13%) patients achieved complete response (CR), all from the mitotane plus LRT group.

CONCLUSION

Our results endorse European and French guidelines for stage IV ACC with 2 or fewer tumor organs and favor the combination of mitotane and LRT as first-line treatment. For the first time, a significant number of CRs were observed. Prospective studies are expected to confirm these findings.

Molecular Mechanisms of Mitotane Action in Adrenocortical Cancer Based on In Vitro Studies

Simple Summary

Mitotane is the only approved drug for the treatment of advanced adrenocortical carcinoma and for postoperative adjuvant therapy. It is known that mitotane destroys the adrenal cortex impairing steroidogenesis, although its exact molecular mechanism is still unclear. However, confounding factors affecting in vitro experiments could reduce the relevance of the studies. In this review, we explore in vitro studies on mitotane effects, highlighting how different experimental conditions might contribute to the controversial findings. On this basis, it may be necessary to re-evaluate the experiments taking into account their potential confounding factors such as cell strains, culture serum, lipoprotein concentration, and culture passages, which could hide important molecular results. As a consequence, the identification of novel pharmacological molecular pathways might be used in the future to implement personalized therapy, maximizing the benefit of mitotane treatment while minimizing its toxicity.

Abstract

Mitotane is the only approved drug for the treatment of advanced adrenocortical carcinoma and is increasingly used for postoperative adjuvant therapy. Mitotane action involves the deregulation of cytochromes P450 enzymes, depolarization of mitochondrial membranes, and accumulation of free cholesterol, leading to cell death. Although it is known that mitotane destroys the adrenal cortex and impairs steroidogenesis, its exact mechanism of action is still unclear. The most used cell models are H295-derived cell strains and SW13 cell lines. The diverging results obtained in presumably identical cell lines highlight the need for a stable in vitro model and/or a standard methodology to perform experiments on H295 strains. The presence of several enzymatic targets responsive to mitotane in mitochondria and mitochondria-associated membranes causes progressive alteration in mitochondrial structure when cells were exposed to mitotane. Confounding factors of culture affecting in vitro experiments could reduce the significance of any molecular mechanism identified in vitro. To ensure experimental reproducibility, particular care should be taken in the choice of culture conditions: aspects such as cell strains, culture serum, lipoproteins concentration, and culture passages should be carefully considered and explicated in the presentation of results. We aimed to review in vitro studies on mitotane effects, highlighting how different experimental conditions might contribute to the controversial findings. If the concerns pointed out in this review will be overcome, the new insights into mitotane mechanism of action observed in-vitro could allow the identification of novel pharmacological molecular pathways to be used to implement personalized therapy.

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.

Rare complication of acute adrenocortical dysfunction in adrenocortical carcinoma after transcatheter arterial chemoembolization: A case report

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare and highly invasive endocrine malignant tumor with a poor prognosis. Although surgical resection is the main treatment for ACC, postoperative recurrence and metastasis have become the important factors of death. Transcatheter arterial chemoembolization (TACE) is an important option for the treatment of advanced ACC with liver metastasis. However, due to the small number of patients treated for ACC, the safety of the operation is not completely clear and needs to be further studied.

CASE SUMMARY

A 47-year-old patient with ACC after surgery was admitted for reexamination by abdominal computerized tomography suggesting liver metastasis. Because the patient expressed reluctance to undergo surgery again, we treated her with TACE for the liver lesions. After treatment, symptoms of acute adrenal dysfunction such as decreased blood pressure, anorexia, and fatigue appeared, which were relieved after hydrocortisone treatment. To date, the patient's liver lesion is well controlled and no other metastases are observed.

CONCLUSION

We report a rare case of acute adrenal hypofunction after TACE. Glucocorticoid supplementation can alleviate the symptoms.

Re-Evaluation of Combinational Efficacy and Synergy of the Italian Protocol In Vitro: Are We Truly Optimizing Benefit or Permitting Unwanted Toxicity?

Introduction: Adrenocortical carcinoma (ACC) is a rare endocrine malignancy, with very poor prognosis as a majority of the patients have advanced disease at the time of diagnosis. Currently, adjuvant therapy for most patients consists of either mitotane (M) alone or in combination with multi-drug chemotherapeutics such as etoposide (E), doxorubicin (D), and cisplatin (P), known as the Italian protocol (IP; EDPM). This multi-drug treatment regimen, however, carries significant toxicity potential for patients. One way to improve toxicity profiles with these drugs in combination is to understand where their synergy occurs and over what dosing range so that lower dose regimens could be applied in combination with equal or improved efficacy. We hypothesize that a better understanding of the synergistic effects as well as the regulation of steroidogenic enzymes during combination therapy may provide more optimized combinational options with good potency and lower toxicity profiles. Methods: Two human ACC cell lines, NCI-H295R (hormonally active) and SW13 (hormonally inactive), were grown in 2D culture in appropriate growth medium. The viability of the cells after treatment with varying concentrations of the drugs (E, D, and P) either alone or in combinations with M was determined using the CellTiter Glow assay after 72 h, and the combination index for each was calculated using Compusyn by the Chou–Talalay method. The expression levels of enzymes associated with steroidogenesis were evaluated by RT-PCR in NCI-H295R. Results: When both cell lines were treated with M (ranging 25–50 μM), +E (ranging 18.75–75 μM), and +D (ranging 0.625–2.5 μM) we observed a synergistic effect (CI < 1) with potency equivalent to the full Italian protocol (IP), whereas combining M + P + D had an antagonistic effect (CI > 1) indicating the negative effect of adding cisplatin in the combination. Comparing the hormonally active and inactive cell lines, M + P + E was antagonistic in NCI-H295R and synergistic in SW13. Treatment of NCI-H295R cells with antagonistic combinations (M + P + D, M + P + E) resulted in a significant decrease in the levels of steroidogenic enzymes STAR, CYP11A1, and CYP21A2 compared to IP (p < 0.05) while M + E + D resulted in increased expression or no significant effect compared to IP across all genes tested. Conclusions: The synergistic effect for M + E + D was significant and equivalent in potency to the full IP in both cell lines and resulted in a steroidogenic gene expression profile similar to or better than that of full IP, warranting further evaluation. Future in vivo evaluation of the combination of M + E + D (with removal of P from the IP regimen) may lower toxicity while maintaining anticancer efficacy in ACC.

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.

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.

The Challenging Pharmacokinetics of Mitotane: An Old Drug in Need of New Packaging

Adrenocortical carcinoma (ACC) is a malignant tumor originating from the adrenal gland cortex with a heterogeneous but overall dismal prognosis in advanced stages. For more than 50 years, mitotane has remained a cornerstone for the treatment of ACC as adjuvant and palliative therapy. It has a very poor aqueous solubility of 0.1 mg/l and high partition coefficient in octanol/water (log P) value of 6. The commercially available dosage form is 500 mg tablets (Lysodren^®). Even at doses up to 6 g/day (12 tablets in divided doses) for several months, > 50% patients do not achieve therapeutic plasma concentration > 14 mg/l due to poor water solubility, large volume of distribution and inter/intra-individual variability in bioavailability. This article aims to give a concise update of the clinical challenges associated with the administration of high-dose mitotane oral therapy which encompass the issues of poor bioavailability, difficult-to-predict pharmacokinetics and associated adverse events. Moreover, we present recent efforts to improve mitotane formulations. Their success has been limited, and we therefore propose an injectable mitotane formulation instead of oral administration, which could bypass many of the main issues associated with high-dose oral mitotane therapy. A parenteral administration of mitotane could not only help to alleviate the adverse effects but also circumvent the variable oral absorption, give better control over therapeutic plasma mitotane concentration and potentially shorten the time to achieve therapeutic drug plasma concentrations considerably.

Mitotane as tablet form is currently the standard treatment for adrenocortical carcinoma. It has been used for 5 decades but suffers from highly variable responses in patients, subsequent adverse effects and overall lower response rate. This can be fundamentally linked to the exceedingly poor water solubility of mitotane itself. In terms of enhancing water solubility, a few research groups have attempted to develop better formulations of mitotane to overcome the issues associated with tablet dosage form. However, the success rate was limited, and these formulations did not make it into the clinics. In this article, we have comprehensively reviewed the properties of these formulations and discuss the reasons for their limited utility. Furthermore, we discuss a recently developed mitotane nanoformulation that led us to propose a novel approach to mitotane therapy, where intravenous delivery supplements the standard oral administration. With this article, we combine the current state of knowledge as a single piece of information about the various problems associated with the use of mitotane tablets, and herein we postulate the development of a new injectable mitotane formulation, which can potentially circumvent the major problems associated to mitotane's poor water solubility.

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.

Complete Remission of Advanced Adrenocortical Cancer Following Mitotane Monotherapy: A Case Report and Literature Review of Predictive Markers

Mitotane has been used for the treatment of adrenocortical cancer (ACC) for over 50 years. Despite its widespread use both in monotherapy and in combination with chemotherapeutics, our knowledge of its mechanism of action and therapeutic efficacy is scarce. The number of patients with advanced ACC who have achieved complete remission documented by detailed clinical data is below ten. We report a case of a 64-year-old woman with a non-functional ACC. Histological examination showed vascular invasion, Ki67 of 10% and a mitotic count of 3/10 high-power field. Immunohistochemistry revealed p53 positivity. Pathological TNM grade was reported as T2N0M0, ENSAT stage 2. Nine months after the initial diagnosis, re-staging CT revealed multiple peritoneal nodules, lymph node and kidney metastases confirmed by histologic examination. Mitotane monotherapy was started with a maintenance dose between 2.0 and 2.5 grams/day. Partial remission was established at six months. Subsequently, for another 12 months, each of the three-monthly CT scans confirmed complete remission. Nineteen months after the initiation of mitotane, an unexpected sudden death occurred. A detailed autopsy work-up, performed in the full awareness of oncological history, confirmed complete remission. The authors review the molecular biomarkers and clinical features reported as predictors of response to mitotane monotherapy.

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.

Three Dimensional Cell Culturing for Modeling Adrenal and Pituitary Tumors

In vitro monolayer conditions are not able to reproduce the complexity of solid tumors, still, there is scarce information about the 3D cell culture models of endocrine tumor types. Therefore, our aim was to develop in vitro 3D tumor models by different methodologies for adrenocortical carcinoma (H295R), pituitary neuroendocrine tumor (RC-4B/C and GH3) and pheochromocytoma (PC-12). Various methodologies were tested. Cell biological assays (cell viability, proliferation and live cell ratio) and steroid hormone production by HPLC-MS/MS method were applied to monitor cellular well-being. Cells in hanging drops and embedded in matrigel formed multicellular aggregates but they were difficult to handle and propagate for further experiments. The most widely used methods: ultra-low attachment plate (ULA) and spheroid inducing media (SFDM) were not the most viable 3D model of RC-4B/C and GH3 cells that would be suitable for further experiments. Combining spheroid generation with matrigel scaffold H295R 3D models were viable for 7 days, RC-4B/C and GH3 3D models for 7–10 days. ULA and SFDM 3D models of PC-12 cells could be used for further experiments up to 4 days. Higher steroid production in 3D models compared to conventional monolayer culture was detected. Endocrine tumor cells require extracellular matrix as scaffold for viable 3D models that can be one reason behind the lack of the usage of endocrine 3D cultures. Our models help understanding the pathogenesis of endocrine tumors and revealing potential biomarkers and therapeutic targets. They could also serve as an excellent platform for preclinical drug test screening.

Combination immunotherapy with ipilimumab and nivolumab in patients with advanced adrenocortical carcinoma: a subgroup analysis of CA209-538

Background: Adrenocortical carcinoma is a rare malignancy, with poor prognosis and limited treatment options for patients with advanced disease. Chemotherapy is the current standard first-line treatment, providing only a modest survival benefit. There is only limited treatment experience with immunotherapy using single-agent anti-PD-1/PD-L1 therapy. To date no clinical trials have been reported using combination immunotherapy with anti-CTLA-4 and anti-PD-1 blockade in this patient population. Methods: CA209-538 is a prospective multicentre clinical trial in patients with advanced rare cancers. Participants received the anti-PD-1 antibody nivolumab (3 mg/kg IV) and the anti-CTLA-4 antibody ipilimumab (1 mg/kg IV) every three weeks for four doses, followed by nivolumab (3 mg/kg IV) every two weeks and continued for up to 96 weeks, until disease progression or unacceptable toxicity. Response was assessed every 12 weeks by RECIST version 1.1. Primary endpoint was clinical benefit rate (complete response, partial response, stable disease at 12 weeks). Results: Six patients with adrenocortical carcinoma were enrolled and received treatment. Two patients (33%) have an ongoing partial response (10 and 25 months +) and two patients (33%) stable disease leading to a disease control rate of 66%. Both responders had tumors with a microsatellite instable phenotype. One patient rapidly progressed shortly after enrollment into the trial and did not undergo restaging. Immunotherapy-related toxicity was reported in all patients, with four patients (67%) experiencing grade 3/4 hepatitis leading to discontinuation of treatment. Conclusions: This is the first treatment experience using ipilimumab and nivolumab combination immunotherapy in patients with advanced adrenocortical carcinoma. Durable responses have been observed in a subset of patients suggesting that this treatment regimen should be further investigated in this patient population.

Tumor Microenvironment in Adrenocortical Carcinoma: Barrier to Immunotherapy Success?

Adrenocortical carcinoma is a rare malignancy with aggressive behavior, with up to 40% of patients presenting with metastases at the time of diagnosis. Both conventional chemotherapeutic regimens and novel immunotherapeutic agents, many of which are currently being tested in ongoing clinical trials, have yielded modest results so far, bringing the need for a deeper understanding of adrenal cancer behavior to the forefront. In the recent years, the tumor microenvironment has emerged as a major determinant of cancer response to immunotherapy and an increasing number of studies on other solid tumors have focused on manipulating the microenvironment in the favor of the host and discovering new potential target molecules. In the present review we aim to explore the characteristics of adrenocortical cancer's microenvironment, highlighting the mechanisms of immune evasion responsible for the modest immunotherapeutic results, and identify novel potential strategies.

Sex Differences on Mitotane Concentration and Treatment Outcome in Patients with Adrenocortical Carcinoma

(1) Background: In clinical settings, data regarding sex are rarely investigated. In women, factors such as body size and composition, hormonal variations, metabolism, and access to care systems and therapy could strongly influence the pharmacological management and the outcome of the therapy. To underline this sex-related difference, we retrospectively collected data from adrenocortical carcinoma patients treated with mitotane, and then evaluated sex-related pharmacokinetics parameters. (2) Methods: A fully validated chromatographic method was used to quantify mitotane concentration in plasma collected from adult patients, also considering the active metabolite ortho,para,dichlorodiphenylethene (o,p'-DDE). Statistical analyses were used to evaluate the sex influence on drugs pharmacokinetics. (3) Results: We found that sex resulted as predictive factor of plasma mitotane and o,p'-DDE concentrations and significantly influenced the attainment of the therapeutic target of mitotane, implying that female sex could be a risk factor of treatment failure. (4) Conclusions: These results suggest that mitotane therapy should be modulated according to patient sex. Furthermore, the proposed approach could contribute to facilitating and disseminating sex-specific pharmacology.

Interplay between glucocorticoids and tumor-infiltrating lymphocytes on the prognosis of adrenocortical carcinoma

Background

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy. Tumor-related glucocorticoid excess is present in ~60% of patients and associated with particularly poor prognosis. Results of first clinical trials using immune checkpoint inhibitors were heterogeneous. Here we characterize tumor-infiltrating T lymphocytes (TILs) in ACC in association with glucocorticoids as potential explanation for resistance to immunotherapy.

Methods

We performed immunofluorescence analysis to visualize tumor-infiltrating T cells (CD3⁺), T helper cells (CD3⁺CD4⁺), cytotoxic T cells (CD3⁺CD8⁺) and regulatory T cells (Tregs; CD3⁺CD4⁺FoxP3⁺) in 146 ACC tissue specimens (107 primary tumors, 16 local recurrences, 23 metastases). Quantitative data of immune cell infiltration were correlated with clinical data (including glucocorticoid excess).

Results

86.3% of ACC specimens showed tumor infiltrating T cells (7.7 cells/high power field (HPF)), including T helper (74.0%, 6.7 cells/HPF), cytotoxic T cells (84.3%, 5.7 cells/HPF) and Tregs (49.3%, 0.8 cells/HPF). The number of TILs was associated with better overall survival (HR for death: 0.47, 95% CI 0.25 to 0.87), which was true for CD4⁺− and CD8⁺ subpopulations as well. In localized, non-metastatic ACC, the favorable impact of TILs on overall and recurrence-free survival was manifested even independently of ENSAT (European Network for the Study of Adrenal Tumors) stage, resection status and Ki67 index. T helper cells were negatively correlated with glucocorticoid excess (Phi=−0.290, p=0.009). Patients with glucocorticoid excess and low TILs had a particularly poor overall survival (27 vs. 121 months in patients with TILs without glucocorticoid excess).

Conclusion

Glucocorticoid excess is associated with T cell depletion and unfavorable prognosis. To reactivate the immune system in ACC by checkpoint inhibitors, an inhibition of adrenal steroidogenesis might be pivotal and should be tested in prospective studies.

Management of Patients With Glucocorticoid-Related Diseases and COVID-19

The ongoing coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is a global health crisis affecting millions of people worldwide. SARS-CoV-2 enters the host cells by binding to angiotensin-converting enzyme 2 (ACE2) after being cleaved by the transmembrane protease serine 2 (TMPRSS2). In addition to the lung, gastrointestinal tract and kidney, ACE2 is also extensively expressed in endocrine tissues, including the pituitary and adrenal glands. Although glucocorticoids could play a central role as immunosuppressants during the cytokine storm, they can have both stimulating and inhibitory effects on immune response, depending on the timing of their administration and their circulating levels. Patients with adrenal insufficiency (AI) or Cushing's syndrome (CS) are therefore vulnerable groups in relation to COVID-19. Additionally, patients with adrenocortical carcinoma (ACC) could also be more vulnerable to COVID-19 due to the immunosuppressive state caused by the cancer itself, by secreted glucocorticoids, and by anticancer treatments. This review comprehensively summarizes the current literature on susceptibility to and outcome of COVID-19 in AI, CS and ACC patients and emphasizes potential pathophysiological mechanisms of susceptibility to COVID-19 as well as the management of these patients in case of SARS-CoV-2. Finally, by performing an in silico analysis, we describe the mRNA expression of ACE2, TMPRSS2 and the genes encoding their co-receptors CTSB, CTSL and FURIN in normal adrenal and adrenocortical tumors (both adenomas and carcinomas).

American Association of Clinical Endocrinology Disease State Clinical Review on the Evaluation and Management of Adrenocortical Carcinoma in an Adult: a Practical Approach

OBJECTIVE

The aim of this Disease State Clinical Review is to provide a practical approach to patients with newly diagnosed adrenocortical carcinoma, as well as to follow-up and management of patients with persistent or recurrent disease.

METHODS

This is a case-based clinical review. The provided recommendations are based on evidence available from randomized prospective clinical studies, cohort studies, cross-sectional and case-based studies, and expert opinions.

RESULTS

Adrenocortical carcinoma is a rare malignancy, often with poor outcomes. For any patient with an adrenal mass suspicious for adrenocortical carcinoma, the approach should include prompt evaluation with detailed history and physical exam, imaging, and biochemical adrenal hormone assessment. In addition to adrenal-focused imaging, patients should be evaluated with chest-abdomen-pelvis cross-sectional imaging to define the initial therapy plan. Patients with potentially resectable disease limited to the adrenal gland should undergo en bloc open surgery by an expert surgeon. For patients presenting with advanced or recurrent disease, a multidisciplinary approach considering curative repeat surgery, local control with surgery, radiation therapy or radiofrequency ablation, or systemic therapy with mitotane and/or cytotoxic chemotherapy is recommended.

CONCLUSION

As most health care providers will rarely encounter a patient with adrenocortical carcinoma, we recommend that patients with suspected adrenocortical carcinoma be evaluated by an expert multidisciplinary team which includes clinicians with expertise in adrenal tumors, including endocrinologists, oncologists, surgeons, radiation oncologists, pathologists, geneticists, and radiologists. We recommend that patients in remote locations be followed by the local health care provider in collaboration with a multidisciplinary team at an expert adrenal tumor program.

ABBREVIATIONS

ACC = adrenocortical carcinoma; ACTH = adrenocorticotropic hormone; BRACC = borderline resectable adrenocortical carcinoma; CT = computed tomography; DHEAS = dehydroepiandrosterone sulfate; EDP = etoposide, doxorubicin, cisplatin; FDG = ¹⁸F-fluorodeoxyglucose; FNA = fine-needle aspiration; HU = Hounsfield units; IVC = inferior vena cava; LFS = Li-Fraumeni syndrome; MEN1 = multiple endocrine neoplasia type 1; MRI = magnetic resonance imaging; OAC = oncocytic adrenocortical carcinoma; PC = palliative care; PET = positron emission tomography.

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.

A case report of neurological adverse events caused by short-term and low-dose treatment of mitotane: The role of therapeutic drug monitoring

RATIONALE

Low-dose mitotane has been widely used for many decades in patients with advanced adrenocortical carcinoma (ACC), which exhibited good safety profiles compared with the high-dose regimen. The clinical efficacy and toxicity of mitotane are closely related to its plasma concentration, and therapeutic drug monitoring (TDM) is recommended. Until now, no severe adverse drug reaction (ADR) related to the toxic plasma level after a short-term treatment of low-dose mitotane has been published.

PATIENT CONCERNS

A 50-year-old Chinese female presented with severe neurological adverse events related to a toxic plasma levels of 42.8 mg/L after 4 months treatment of low-dose mitotane.

DIAGNOSES

During the course of therapy, no other medication could cause neurological adverse events. Therefore, we suspected a high sensitivity to the side effect of mitotane related to a toxic plasma level.

INTERVENTIONS

Treatment of mitotane was stopped.

OUTCOMES

The trough plasma concentration of mitotane decreased to 18.7 mg/mL after one and a half months, and the neurological symptoms gradually improved after drug discontinuance.

LESSONS

The present case provides the first report of severe neurological adverse events induced by the short-term use of low-dose mitotane for adjuvant treatment in a patient with ACC, indicating that potentially severe ADR can also occur when using low-dose regimen in the early stage of treatment. TDM and early recognition could result in a favorable outcome.

Unwanted Hormonal and Metabolic Effects of Postoperative Adjuvant Mitotane Treatment for Adrenocortical Cancer

Simple Summary

Mitotane is the only drug approved for treatment of adrenocortical cancer. Although mitotane is a derivative of the pesticide dichlorodiphenyltrichloroethane (DDT), limited data are available on its toxicity. Herein, we reported on the type and frequency of mitotane adverse events and on supportive therapies used to deal with toxicity in 74 mitotane-treated patients. Beyond the expected glucocorticoid insufficiency, a significant number of patients had a deficit of mineralocorticoid hormones, hypothyroid state and impaired testicular function, while fertile women frequently developed ovarian cysts during mitotane treatment. Multiple hormone replacement therapies were needed in >30% of patients. Statins were used in 50% of patients for significant hypercholesterolemia. Supportive therapies were able to revert the biochemical alterations, although higher doses were frequently used due to pharmacokinetic interactions with mitotane. Our study underlines the need of a careful and global approach to manage mitotane toxicity, to make adjuvant therapy safer and easier for patients.

Abstract

Mitotane is widely used for the treatment of adrenocortical cancer (ACC), although the drug-related toxicity complicates its use. The aim of this study is to assess comprehensively the different endocrine and metabolic unwanted effects of the drug, and to provide data on the supportive therapies. We retrospectively analyzed 74 ACC patients adjuvantly treated with mitotane for ≥12 months. During the treatment period (40 months, 12–195), 32.4% of patients needed replacement therapy for mineralocorticoid deficit, 36.2% for hypothyroidism and 34.3% for male hypogonadism. In fertile women, hypogonadism was uncommon, while 65.4% of women developed ovarian cysts. Although no significant change in low-density lipoprotein (LDL) was observed, statins were started in 50% of patients for a significant increase in total cholesterol and triglycerides. Dyslipidemia occurred early, after a median time of 6 months from mitotane start. Conversely, testosterone replacement was usually started after >2 years. In many cases, ranging from 29.4% to 50% according to the side effect, toxicity occurred well before the achievement of the target mitotane concentrations. Supportive therapies were able to revert the biochemical alterations induced by mitotane, although higher doses were needed for a likely pharmacokinetic interaction of exogenous steroids and statins with mitotane. In conclusion, adjuvant mitotane therapy is associated with a spectrum of unwanted effects encompassing the function of different endocrine glands and requires a careful clinical and biochemical assessment associated with the therapeutic drug monitoring.