Safe long-term therapy of Cushing's syndrome over 37 years with mitotane

While suggested, surgery is not always possible as a first-line treatment of Cushing's Disease (CD). In such cases, patients require medical therapy in order to prevent complications resulting from hypercortisolism. Although there has been a wide expansion in pharmacological options in recent years, mitotane was the agent of choice for treating hypercortisolism decades ago. Due to the introduction of other therapies, long-term experience with mitotane remains limited. Here, we report the case of a woman with CD who was treated with mitotane for 37 years. During the treatment period, biochemical and clinical disease control was achieved and the patient had two uncomplicated pregnancies. Drug-related side effects remained moderate and could be controlled by several dose adjustments. Our case highlights the ability of mitotane to allow an effective control of hypercortisolism and to represent a safe treatment option in special situations where CD requires an alternative therapeutic approach. Furthermore, we provide a literature review of the long-term use of mitotane and reported cases of pregnancy in the context of mitotane therapy.

Recovery of adrenal function after stopping mitotane in patients with adrenocortical carcinoma

OBJECTIVE

Mitotane is the standard therapy of adrenocortical carcinoma (ACC) due to its relative selectivity of its cytotoxic effects toward adrenocortical cells. Therefore, it virtually always leads to adrenal insufficiency. Frequency and characteristics of hypothalamic-pituitary-adrenal axis recovery after discontinuation are ill-defined.

METHODS

This was a retrospective study of patients with ACC adjuvantly treated with mitotane for ≥12 months who were disease-free at mitotane stop and had a minimum follow-up ≥1 year. Primary endpoint was adrenal recovery. Cox regression analyses were used to identify predictive factors. Moreover, mitotane plasma elimination rate and hormonal changes after mitotane stop were investigated.

RESULTS

Fifty-six patients (36 women) treated with mitotane for a median time of 25 months and an average daily dose of 2.8 g were included. Median time after discontinuation until mitotane levels dropped below 5 and 2 mg/L, and the detection limit was 152 days (interquartile range: 114-202), 280 days (192-370), and 395 days (227-546), respectively. Full adrenal recovery was documented in 32 (57%) patients after a median time of 26 months (95% confidence interval [CI] = 19.6-32.4). In 4 patients (7.1%), adrenal insufficiency persisted >5 years after discontinuation. Mitotane peak ≥ 27 mg/L significantly correlated with longer time to adrenal recovery (hazard ratio [HR] = 0.2, 95% CI = 0.1-0.8, P = .03). Twenty-seven of 38 patients (71%) followed in reference centers achieved adrenal recovery compared with only 5/18 (28%) followed up in non-reference centers (HR = 4.51, 95% CI = 1.71-11.89, P = .002). Other investigated factors were not associated with adrenal function after discontinuation.

CONCLUSIONS

Our study demonstrates that adrenal recovery occurs in most patients after stopping mitotane, particularly when followed up in specialized centers, but not in all. Elimination time of mitotane after treatment discontinuation is very long but individually quite variable.

Hypogonadism and sexual function in men affected by adrenocortical carcinoma under mitotane therapy

Purpose

Adrenocortical carcinoma (ACC) is a rare and aggressive tumor. ACC male patients under adjuvant mitotane therapy (AMT) frequently develop hypogonadism, however sexual function has never been assessed in this setting. The aim of this retrospective study was to evaluate in AMT treated ACC patients the changes in Luteinizing hormone (LH), Sex Hormone Binding Globulin (SHBG), total testosterone (TT) and calculated free testosterone (cFT), the prevalence and type of hypogonadism and sexual function, the latter before and after androgen replacement therapy (ART).

Methods

LH, SHBG, TT and cFT were assessed in ten ACC patients at baseline (T0) and six (T1), twelve (T2), and eighteen (T3) months after AMT. At T3, ART was initiated in eight hypogonadal patients, and LH, SHBG, TT and cFT levels were evaluated after six months (T4). In six patients, sexual function was evaluated before (T3) and after (T4) ART using the International Index of Erectile Function-15 (IIEF-15) questionnaire.

Results

Under AMT we observed higher SHBG and LH and lower cFT levels at T1-T3 compared to T0 (all p<0.05). At T3, hypergonadotropic hypogonadism and erectile dysfunction (ED) were detected in 80% and 83.3% of cases. At T4, we observed a significant cFT increase in men treated with T gel, and a significant improvement in IIEF-15 total and subdomains scores and ED prevalence (16.7%) in men under ART.

Conclusion

AMT was associated with hypergonatropic hypogonadism and ED, while ART led to a significant improvement of cFT levels and sexual function in the hypogonadal ACC patients. Therefore, we suggest to evaluate LH, SHBG, TT and cFT and sexual function during AMT, and start ART in the hypogonadal ACC patients with sexual dysfunction.

Effect of mitotane in patients with ectopic adrenocorticotropic hormone syndrome caused by advanced pancreatic neuroendocrine tumors: a case series and review of the literature

Ectopic adrenocorticotropic hormone syndrome (EAS) is a rare condition caused by pancreatic neuroendocrine tumors (p-NETs). The severe hypercortisolemia that characterizes EAS is associated with a poor prognosis and survival. Mitotane is the only adrenolytic drug approved by the Food and Drug Administration and is often used to treat adrenocortical carcinoma. Combination therapy with mitotane and other adrenal steroidogenesis inhibitors is common for patients with Cushing's syndrome (CS). Here, we describe three patients who developed EAS secondary to the liver metastasis of p-NETs. All three rapidly developed hypercortisolemia but no typical features of CS. They underwent anti-tumor and mitotane therapy, which rapidly reduced their blood cortisol concentrations and ameliorated their symptoms. Their hypercortisolemia was controlled long term using a low dose of mitotane. The principal adverse effects were a slight loss of appetite and occasional dizziness, and there were no severe adverse effects. Importantly, even when the tumor progressed, the patients' circulating cortisol concentrations remained within the normal range. In summary, the present case series suggests that mitotane could be used to treat hypercortisolemia in patients with EAS caused by advanced p-NETs, in the absence of significant adverse effects.

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.

Two-dimensional chromatography for enantiomeric analysis of mitotane and its metabolite o,p'-DDA in patients with adrenocortical carcinoma indicates enantioselective metabolism

Mitotane is a chiral drug used to treat adrenocortical carcinoma, being metabolized to the o,p'-dichlorodiphenyl acetic acid (o,p'-DDA), also a chiral compound. Despite of its therapeutic significance, the overall ratios and enantiomers have not been known. In this study, we analyzed the enantiomers of mitotane and o,p'-DDA in the plasma of patients by a newly developed chiral-phase method employed in two-dimensional chromatography. Important differences were observed in the ratio of (S)/(R)-mitotane, which varied substantially from 1:1.2 to 1:10 whereas the (S)/(R)-o,p'-DDA ratio was relatively conserved, at approximately 2:1. These findings provide evidence for the enantioselective metabolism and provide a method for further analyses of mitotane and metabolites, which can explain the variation in the therapeutic response.

Albumin/Mitotane Interaction Affects Drug Activity in Adrenocortical Carcinoma Cells: Smoke and Mirrors on Mitotane Effect with Possible Implications for Patients' Management

BACKGROUND

Mitotane is the only drug approved for the treatment of adrenocortical carcinoma (ACC). Although it has been used for many years, its mechanism of action remains elusive. H295R cells are, in ACC, an essential tool to evaluate drug mechanisms, although they often lead to conflicting results.

METHODS

Using different in vitro biomolecular technologies and biochemical/biophysical experiments, we evaluated how the presence of "confounding factors" in culture media and patient sera could reduce the pharmacological effect of mitotane and its metabolites.

RESULTS

We discovered that albumin, the most abundant protein in the blood, was able to bind mitotane. This interaction altered the effect of the drug by blocking its biological activity. This blocking effect was independent of the albumin source or methodology used and altered the assessment of drug sensitivity of the cell lines.

CONCLUSIONS

In conclusion, we have for the first time demonstrated that albumin does not only act as an inert drug carrier when mitotane or its metabolites are present. Indeed, our experiments clearly indicated that both albumin and human serum were able to suppress the pharmacological effect of mitotane in vitro. These experiments could represent a first step towards the individualization of mitotane treatment in this rare tumor.

Adjuvant mitotane versus surveillance in low-grade, localised adrenocortical carcinoma (ADIUVO): an international, multicentre, open-label, randomised, phase 3 trial and observational study

BACKGROUND

Adjuvant treatment with mitotane is commonly used after resection of adrenocortical carcinoma; however, treatment remains controversial, particularly if risk of recurrence is not high. We aimed to assess the efficacy and safety of adjuvant mitotane compared with surveillance alone following complete tumour resection in patients with adrenocortical carcinoma considered to be at low to intermediate risk of recurrence.

METHODS

ADIUVO was a multicentre, open-label, parallel, randomised, phase 3 trial done in 23 centres across seven countries. Patients aged 18 years or older with adrenocortical carcinoma and low to intermediate risk of recurrence (R0, stage I-III, and Ki67 ≤10%) were randomly assigned to adjuvant oral mitotane two or three times daily (the dose was adjusted by the local investigator with the target of reaching and maintaining plasma mitotane concentrations of 14-20 mg/L) for 2 years or surveillance alone. All consecutive patients at 14 study centres fulfilling the eligibility criteria of the ADIUVO trial who refused randomisation and agreed on data collection via the European Network for the Study of Adrenal Tumors adrenocortical carcinoma registry were included prospectively in the ADIUVO Observational study. The primary endpoint was recurrence-free survival, defined as the time from randomisation to the first radiological evidence of recurrence or death from any cause (whichever occurred first), assessed in all randomly assigned patients by intention to treat. Overall survival, defined as time from the date of randomisation to the date of death from any cause, was a secondary endpoint analysed by intention to treat in all randomly assigned patients. Safety was assessed in all patients who adhered to the assigned regimen, which was defined by taking at least one tablet of mitotane in the mitotane group and no mitotane at all in the surveillance group. The ADIUVO trial is registered with ClinicalTrials.gov, NCT00777244, and is now complete.

FINDINGS

Between Oct 23, 2008, and Dec 27, 2018, 45 patients were randomly assigned to mitotane and 46 to surveillance alone. Because the study was discontinued prematurely, 5-year recurrence-free and overall survival are reported instead of recurrence-free and overall survival as defined in the protocol. 5-year recurrence-free survival was 79% (95% CI 67-94) in the mitotane group and 75% (63-90) in the surveillance group (hazard ratio 0·74 [95% CI 0·30-1·85]). Two people in the mitotane group and five people in the surveillance group died, and 5-year overall survival was not significantly different (95% [95% CI 89-100] in the mitotane group and 86% [74-100] in the surveillance group). All 42 patients who received mitotane had adverse events, and eight (19%) discontinued treatment. There were no grade 4 adverse events or treatment-related deaths.

INTERPRETATION

Adjuvant mitotane might not be indicated in patients with low-grade, localised adrenocortical carcinoma considering the relatively good prognosis of these patients, and no significant improvement in recurrence-free survival and treatment-associated toxicity in the mitotane group. However, the study was discontinued prematurely due to slow recruitment and cannot rule out an efficacy of treatment.

FUNDING

AIFA, ENSAT Cancer Health F2-2010-259735 programme, Deutsche Forschungsgemeinschaft, Cancer Research UK, and the French Ministry of Health.

New Findings on Presentation and Outcome of Patients With Adrenocortical Cancer: Results From a National Cohort Study

CONTEXT

Because of the rarity of adrenocortical cancer (ACC), only a few population-based studies are available, and they reported limited details in the characterization of patients and their treatment.

OBJECTIVE

To describe in a nationwide cohort the presentation of patients with ACC, treatment strategies, and potential prognostic factors.

METHODS

Retrospective analysis of 512 patients with ACC, diagnosed in 12 referral centers in Italy from January 1990 to June 2018.

RESULTS

ACC diagnosed as incidentalomas accounted for overall 38.1% of cases, with a frequency that increases with age and with less aggressive pathological features than symptomatic tumors. Women (60.2%) were younger than men and had smaller tumors, which more frequently secreted hormones. Surgery was mainly done with an open approach (72%), and after surgical resection, 62.7% of patients started adjuvant mitotane therapy. Recurrence after tumor resection occurred in 56.2% of patients. In patients with localized disease, cortisol secretion, ENSAT stage III, Ki67%, and Weiss score were associated with an increased risk of recurrence, whereas margin-free resection, open surgery, and adjuvant mitotane treatment were associated with reduced risk. Death occurred in 38.1% of patients and recurrence-free survival (RFS) predicted overall survival (OS). In localized disease, age, cortisol secretion, Ki67%, ENSAT stage III, and recurrence were associated with increased risk of mortality. ACCs presenting as adrenal incidentalomas showed prolonged RFS and OS.

CONCLUSION

Our study shows that ACC is a sex-related disease and demonstrates that an incidental presentation is associated with a better outcome. Given the correlation between RFS and OS, RFS may be used as a surrogate endpoint in clinical studies.

Inflammation-based scores as predictors of treatment response in advanced adrenocortical carcinoma

Treatment for advanced adrenocortical carcinoma (ACC) consists of mitotane alone or combined with etoposide, doxorubicin, and cisplatin (EDP). Although both therapies are widely used, markers of response are still lacking. Since inflammation-based scores have been proposed as prognostic factors in ACC, we aimed to investigate their role in predicting the response to first-line chemotherapy. We performed a retrospective analysis of patients with advanced ACC treated with mitotane monotherapy or EDP ± mitotane. Clinical parameters (tumour stage at diagnosis, resection status, Ki67, time from diagnosis to treatment start, performance status, plasma mitotane levels, time in mitotane target ≥ 80%, clinically overt cortisol hypersecretion), and pretreatment inflammation-based scores (neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), monocyte-to-lymphocyte ratio, derived neutrophil-to-lymphocyte ratio) were investigated. The primary endpoints were overall survival (OS) and time-to-progression (TTP) from treatment initiation, the secondary endpoint was the best objective response to treatment. We included 90 patients (59% = women, median age = 51 years) treated with mitotane monotherapy (n = 40) or EDP ± mitotane (n = 50). In the mitotane monotherapy cohort, NLR ≥ 5 and PLR ≥ 190 predicted shorter OS (hazard ratio (HR): 145.83, 95% CI: 1.87-11,323.83; HR: 165.50, 95% CI: 1.76-15,538.04, respectively), remaining significant at multivariable analysis including clinical variables. NLR was also associated with shorter TTP (HR: 2.58, 95% CI: 1.28-5.20), but only at univariable analysis. Patients with NLR ≥ 5 showed a worse treatment response than those with NLR < 5 (P = 0.040). In the EDP ± mitotane cohort, NLR ≥ 5 predicted shorter OS (HR: 2.52, 95% CI: 1.30-4.88) and TTP (HR: 1.95, 95% CI: 1.04-3.66) at univariable analysis. In conclusion, inflammation-based scores, calculated from routinely measured parameters, may help predict response to chemotherapy in advanced ACC.

A Systematic Review of Published Clinical Trials in the Systemic Treatment of Adrenocortical Carcinoma: An Initiative Led on Behalf of the Global Society of Rare Genitourinary Tumors

Adrenocortical carcinoma (ACC) is a very rare endocrine cancer and is associated with a poor prognosis. There is a paucity of randomized clinical trials for this rare disease. We aimed to perform a systematic review of the literature on systemic therapy options in different stages of ACC. A systematic review was performed using Pubmed and Embase databases according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. A total of 24 trials of systemic therapy in the treatment of ACC were identified and included in this review. Only one clinical trial in the adjuvant setting was identified, the negative phase III trial ADIUVO, which tested mitotane in low to intermediate-risk ACC patients. In the treatment of advanced ACC, cisplatin-based chemotherapy was evaluated in small and non-randomized phase II trials, and response rates ranged from 21% to 53.5%. The phase III trial FIRM-ACT compared etoposide, doxorubicin, cisplatin, and mitotane versus treatment with streptozotocin and mitotane and showed no difference in OS, but higher RR and PFS were reported with the multi-drug regimen. Six clinical trials of immunotherapy and seven studies of targeted therapy in advanced ACC were included, with modest activity and no phase 3 trials were identified. Treatment recommendations of ACC are based on retrospective and small studies with limited systemic therapy options. International and multi-center collaboration is essential to expand clinical research and improve outcomes.

The management of postoperative disease recurrence in patients with adrenocortical carcinoma: a retrospective study in 106 patients

OBJECTIVE

The management of adrenocortical carcinoma (ACC) recurrences remains controversial, and we present herein our experience with postoperative ACC recurrences.

DESIGN AND METHODS

Retrospective analysis in a single reference center of 106 patients with ACC recurrence.

RESULTS

The median follow-up was 45 months, the median recurrence-free survival (RFS) 12 months (IQR 6-23), and the median overall survival (OS) 45 months (IQR 29-75). ACC recurrences occurred as a unique lesion (group A) in 35.8%, multiple lesions in a single organ (group B) in 20.8%, and affecting multiple organs (group C) in 43.4% of patients. Baseline characteristics of patients stratified by the type of recurrence did not differ between them, except RFS, which was significantly longer in group A. Locoregional treatments were used in 100% of patients of group A, 68.2% in group B, and 26.1% in group C. After treatment of recurrence, 60.4% of patients became free of disease attaining a second RFS of 15 months (IQR 6-64). Margin status RX and R1, percent increase in Ki67, and recurrence in multiple organs were associated with an increased risk of mortality, while adjuvant mitotane treatment and longer time to first recurrence were associated with reduced risk. Recurrence in multiple organs and systemic treatment of recurrence had a negative impact on survival from the treatment of recurrence.

CONCLUSIONS

This study shows that patients with ACC have a better prognosis when the disease recurs as a single lesion and supports the use of locoregional treatments to treat disease recurrence.

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.

Supportive therapies in patients with advanced adrenocortical carcinoma submitted to standard EDP-M regimen

PURPOSE

The management of patients with advanced/metastatic adrenocortical carcinoma (ACC) is challenging, EDP-M (etoposide, doxorubicin, cisplatin combined with mitotane) is the standard regimen. However, it is quite toxic, so an adequate supportive therapy is crucial to reduce as much as possible the side effects and maintain the dose intensity of cytotoxic agents.

METHODS

We describe the main side effects of the EDP-M scheme and the best way to manage them based on the experience of the Medical Oncology Unit of the Spedali Civili of Brescia. We also deal with the administration of EDP-M in specific frail patients, such as those with huge disease extent and poor performance status (PS) and those with mild renal insufficiency.

RESULTS

In patients with hormone secreting ACC the rapid control of Cushing syndrome using adrenal steroidogenesis inhibitors such as metyrapone or osilodrostat is mandatory before starting EDP-M. Primary prophylaxis of neutropenia with Granulocyte-Colony Stimulating Factors is crucial and should be introduced at the first chemotherapy cycle. Possible mitotane induced hypoadrenalism should be always considered in case of persistent nausea and vomiting and asthenia in the interval between one cycle to another. In case of poor PS. A 24 h continuous infusion schedule of cisplatin could be an initial option in patients with poor PS as well as to reduce the risk of nefrotoxocity in patients with mild renal impairment.

CONCLUSION

A careful and accurate supportive care is essential to mitigate EDP-M side effects as much as possible and avoid that, due to toxicity, patients have to reduce doses and or postpone cytotoxic treatment with a negative impact on efficacy of this chemotherapy regimen.

Key factors for effective mitotane therapy in children with adrenocortical carcinoma

Adjuvant treatment with mitotane and chemotherapy is recommended for paediatric advanced and metastatic adrenocortical carcinoma (ACC). Yet, questions on the indication, dosage, and length of therapy are unanswered. Data from the German Paediatric Oncology Haematology-Malignant Endocrine Tumour studies were analysed retrospectively for patients receiving mitotane during first- and/or second-line therapy. Forty-three patients were identified (median age: 7.5 years (range: 0.2-17.8); 29 female) with median follow-up of 2.2 years (range: 0.04-12.71). Three-year overall (OS) and progression-free survival (PFS) were 44.9% and 28.5%, respectively. Eleven of 43 patients received mitotane as neoadjuvant treatment, and 4/11 tumours reached partial remission (PR). Twenty-seven of 43 patients received mitotane combined with chemotherapy in an adjuvant setting resulting in PR of measurable target lesions in 5/13 patients. Metastatic disease (hazard ratio (HR): 3.2; 95% CI: 1.2-18.6; P = 0.018), duration of mitotane treatment <9 months (HR: 5.6; 95% CI: 1.9-16.9; P = 0.002), and not achieving drug target range (TR) (HR: 28.5; 95% CI: 5.4-150.3; P < 0.001) significantly impacted as negative prognostic factors upon PFS and OS (metastatic disease: HR: 4.9; 95% CI: 1.6-15.5; P = 0.006; duration of mitotane treatment: HR: 7.0: 95% CI 1.9-26.0; P = 0.004; TR not reached: HR: 13.5; 95% CI 3.6-50.3; P < 0.001). Cox regression determined the risk of event decreasing by 10.4% for each month of mitotane treatment (P = 0.015). Re-treatment with mitotane after first-line treatment proved ineffective. The duration of mitotane treatment and reaching mitotane TR significantly impacted survival. Improving the efficacy of mitotane, including appropriate indications, needs to be evaluated in prospective randomized trials.

Mitotane Targets Lipid Droplets to Induce Lipolysis in Adrenocortical Carcinoma

INTRODUCTION

Adrenocortical carcinoma (ACC) is a rare aggressive cancer with low overall survival. Adjuvant mitotane improves survival but is limited by poor response rates and resistance. Mitotane's efficacy is attributed to the accumulation of toxic free cholesterol, predominantly through cholesterol storage inhibition. However, targeting this pathway has proven unsuccessful. We hypothesize that mitotane-induced free-cholesterol accumulation is also mediated through enhanced breakdown of lipid droplets.

METHODOLOGY

ATCC-H295R (mitotane-sensitive) and MUC-1 (mitotane-resistant) ACC cells were evaluated for lipid content using specific BODIPY dyes. Protein expression was evaluated by immunoblotting and flow cytometry. Cell viability was measured by quantifying propidium iodide-positive cells following mitotane treatment and pharmacological inhibitors of lipolysis.

RESULTS

H295R and MUC-1 cells demonstrated similar neutral lipid droplet numbers at baseline. However, evaluation of lipid machinery demonstrated distinct profiles in each model. Analysis of intracellular lipid droplet content showed H295R cells preferentially store cholesteryl esters, whereas MUC-1 cells store triacylglycerol. Decreased lipid droplets were associated with increased lipolysis in H295R and in MUC-1 at toxic mitotane concentrations. Pharmacological inhibition of lipolysis attenuated mitotane-induced toxicity in both models.

CONCLUSION

We highlight that lipid droplet breakdown and activation of lipolysis represent a putative additional mechanism for mitotane-induced cytotoxicity in ACC. Further understanding of cholesterol and lipids in ACC offers potential novel therapeutic exploitation, especially in mitotane-resistant disease.

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.

[A Case Report of a Patient with Metastatic Adrenocortical Carcinoma who Received the Combination Etoposide, Doxorubicin, Cisplatin, and Mitotane Therapy and Achieved Remission]

A 40-year-old Japanese female was referred to our institution with a high serum lactate dehydrogenase level. Computed tomography (CT) showed a large right adrenal tumor, 14 cm in size without distant metastases. The patient was clinically diagnosed with T2N0M0 adrenocortical carcinoma and underwent right adrenalectomy. The pathological diagnosis was adrenocortical carcinoma with negative surgical margin. The patient was administered mitotane for 2 years as adjuvant therapy. Subsequently, CT revealed asynchronous multiple metastases, including liver, lung, left kidney, and right acetabulum. The patient received 15 courses of EDP (a combination of etoposide, doxorubicin, and cisplatin) plus mitotane therapy, and had stable disease without new lesions.

Temporal Trends in Outcomes in Patients With Adrenocortical Carcinoma: A Multidisciplinary Referral-center Experience

CONTEXT

Reporting temporal trends in adrenocortical carcinoma (ACC) helps guide management strategies.

OBJECTIVE

This work aimed to report the trends in disease burden and clinical outcomes over time that cannot be adequately captured from individual clinical trials.

METHODS

A retrospective study was held of ACC patients seen at a referral cancer center between February 1998 and August 2019. Clinical outcomes were compared between an early cohort (February 1998-June 2007) and a late cohort (July 2007-August 2019).

RESULTS

A total of 621 patients included with a median age at diagnosis of 49.3 years (range, 0.5-86.6 years). There were 285 (45.9%) patients with hormonal overproduction. More patients in the late cohort had stage IV disease compared to the early cohort (36.8% vs 23.1%; P < .0001). Resection of the primary tumor was performed in 502 patients (80.8%). Complete resection (R0) was more common in the late cohort (165 [60.2%]) than in the early cohort (100 [44.6%]; P = .0005). Of 475 patients with metastatic disease (stage IV or recurrent metastatic disease), 352 (74.1%) received mitotane, 320 (67.4%) received chemotherapy, and 53 (11.2%) received immunotherapy. In the early cohort, 70 (33%) received 2 or more lines of therapy, whereas in the late cohort, 127 (48%) received 2 or more lines of therapy. The 5-year overall survival (OS) rates were 65%, 58%, 45%, and 10% for stage I, II, III, and IV disease, respectively, whereas the 2-year OS rates in patients with stage IV disease was 24% in the early cohort and 46% in the late cohort (P = .01).

CONCLUSION

ACC clinical outcomes improved over the past 2 decades as more patients had complete resection or received more lines of systemic therapy.

Spironolactone is associated with reduced mitotane levels in adrenocortical carcinoma patients

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with a poor prognosis. Mitotane, a derivative of the pesticide dichlorodiphenyltrichloroethane, has been used successfully as first line chemotherapy since the 1960s, if maintained within a narrow therapeutic window. Spironolactone (SPL) is frequently used to treat glucocorticoid excess-associated adverse effects such as severe hypokalemia. Although data of a previous case report indicate a link, valid data regarding SPL use and mitotane plasma concentrations in a human cohort are lacking.This retrospective analysis includes data from 54 mitotane-receiving ACC patients (14 co-administered with SPL) treated between January 2005 and April 2020 (20 male, mean age 54.1 ± 2.2 years). All available mitotane concentrations, treatment doses, tumor stage and evidence of hormone activity were collected. Primary outcomes included mitotane levels and concentration/dose ratios as well as time-in-range (TR) in patients with and without additional SPL treatment. The SPL group was characterized by higher glucocorticoid secretion. Other features such as tumor stage, size and anthropometrics were similar between groups. Interestingly, the SPL group had significantly lower mitotane levels despite higher doses. Mitotane TR was significantly reduced in the SPL group, as was time-in-range to progression. These data provide first evidence in a human cohort for potential SPL-mitotane interactions (beyond mentioned case report), which affect dose response and may modulate treatment outcomes. This should caution clinicians to carefully adjust mitotane doses during SPL treatment in ACC patients or choose alternative therapeutic options.

Pediatric adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy of the adrenal gland with an unfavorable prognosis. It is rare in the pediatric population, with an incidence of 0.2-0.3 patients per million in patients under 20 years old. It is primarily associated with Li-Fraumeni and Beckwith-Wiedemann tumor predisposition syndromes in children. The incidence of pediatric ACC is 10-15fold higher in southern Brazil due to a higher prevalence of TP53 mutation associated with Li-Fraumeni syndrome in that population. Current treatment protocols are derived from adult ACC and consist of surgery and/or chemotherapy with etoposide, doxorubicin, and cisplatin (EDP) with mitotane. Limited research has been reported on other treatment modalities for pediatric ACC, including mitotane, pembrolizumab, cabozantinib, and chimeric antigen receptor autologous cell (CAR-T) therapy.

Prognostic factors and mitotane treatment of adrenocortical cancer. Two decades of experience from an institutional case series

OBJECTIVES

This study aimed to characterise the clinicopathological features and prognostic factors of a large cohort of Hungarian patients with adrenocortical cancer diagnosed between 2000-2021.

PATIENTS AND METHODS

This retrospective study included seventy-four patients (27 men and 47 women) with histologically confirmed adrenocortical cancer in a single tertiary referral endocrine centre. Descriptive statistics were performed, providing summaries of selected clinical and pathological parameters. Clinicopathological factors contributing to overall survival were analysed.

RESULTS

The median age of patients was 48,5 years (17-84 years) at diagnosis. The majority of cases were diagnosed at ENSAT stage II (39,2%) and stage IV (33,8%). At diagnosis, the median tumour size was 9,0 cm (4,5-20 cm). In 47 patients (71,6%), the tumour was hormonally active. The median overall survival and the 5-year survival rate were 23,5 months (95% CI, 17-30,5 months) and 18,3%, respectively. Primary tumour resection was performed in 68 patients (91,8%); R0 surgical resection was achieved in 30 patients. In univariate Cox regression model, tumours with stages III and IV, high proliferative activity (Ki67-index > 10%), R1-R2 surgical resection state and hormonal activity were associated with poorer survival. Cortisol excess, both isolated and combined with androgen production, was associated with poorer survival. Fifty-five patients were treated with mitotane. The overall survival of patients achieving therapeutic mitotane plasma concentration was significantly better compared to those who never reached it [27.0 (2-175) months vs 18.0 (2-83) months; p<0.05)]. The median age, the distribution of gender, ENSAT stage, resection state and Ki67-index did not differ between these two groups. The time needed to reach the therapeutic range of serum mitotane was 96.5 days (95% CI, 75-133 days).

CONCLUSION

Our results confirm previous data that disease stage, mitotic activity, the resection state and the mitotane treatment achieving therapeutic concentration are the most critical parameters influencing the prognosis of adrenocortical cancer. Our data suggest that hormonal activity may be more frequent than described previously, and it is a strong and independent prognostic factor of overall survival. To our knowledge, this is the first single-centre study confirming the prognostic importance of achieving therapeutic mitotane concentration.

The function of adrenal glands in children and adolescents during and after oncological treatment

The purpose of this work was to present the current state of knowledge on the effects of frequently used therapeutic forms, selected pharmacotherapy (including glucocorticosteroids, immune checkpoint inhibitors, mitotane, metyrapone, aminoglutetimide, etomidate, ketoconazole, fluconazole), but also radiation therapy on the functioning of the hypothalamic-pituitary-adrenal axis in children and adolescent during and after oncological treatment. The most common pediatric cancers, where complications of adrenal insufficiency occur, are presented. Moreover, current recommendations how to diagnose the function of the adrenal axis in oncological pediatric patients, as well during oncological treatment as after it, including patients treated with steroids and also patients in severe stages, are reported. The rules of the treatment of adrenal dysfunction in those patients are presented. This understanding is of key importance for oncologists and endocrinologists in the process of diagnosing, treating and developing patient health care, as well as during therapy as after it, offering safety and improving the quality of life.

Different management of adrenocortical carcinoma in children compared to adults: is it time to share guidelines?

Pediatric and adult adrenocortical carcinomas differ in many respects but treatment is often similar in both age groups. The Journal of Clinical Oncology recently published the results of a risk-stratified single-arm interventional trial conducted by the Children's Oncology Group in which 77 patients were treated in three different interventional cohorts. In this Point of View paper we comment on the treatment strategies adopted within the ARAR0332 trial in terms of surgery approach, duration of adjuvant therapies, and palliative chemotherapy. We focus on the differences in the treatment of pediatric ACC patients compared to the ESE/ENSAT and ESMO guidelines released in 2018 for adult patients. For example, patients in stratum 3 and 4 received 8 (instead of 6) cycles of EDP chemotherapy but 8 months (instead of 24) of mitotane adjuvant therapy. Bearing clearly in the mind that pediatric and adult ACC patients represent different settings, we wonder whether there could be some areas of intervention overlapping to constitute a continuum of disease across ages. Thus, pediatric and adult cohoperative groups should be encouraged to collaborate in order to reach common guidelines for the treatment of such a rare disease.

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.

Medical therapy in severe hypercortisolism

Severe hypercortisolism is characterized as a life-threatening endocrine condition in patients with Cushing syndrome, usually related to the concomitant onset of one or more comorbidities, requiring rapid normalization of cortisol concentrations and aggressive treatment of associated complications. It is mainly, but not exclusively, caused by ectopic ACTH syndrome, and the diagnosis of severity is more accurate when is based on simultaneous evaluation of the clinical course and manifestations of the disease, cortisol levels and systematic search of comorbidities. Once the severity and imminent risk to life are established, urgent therapeutic measures must be taken and etiological investigation postponed until the patient is stabilized. Adrenal steroidogenesis inhibitors (mainly etomidate, ketoconazole, and metyrapone), alone or in combined therapy, are commonly the first-line treatment for severe hypercortisolemia due to their rapid action, good efficacy and safety profile. The new drug osilodrostat is a future potential candidate to be included in the list. The glucocorticoid receptor antagonist mifepristone has also a rapid action, but its use has been limited due to difficulties to monitor its efficacy and safety. Other slow-acting cortisol-lowering drugs (mainly mitotane, cabergoline, and pasireotide) might be included in the therapeutic scheme to synergize and overcome a possible escape phenomenon frequently observed with the fast-acting drugs in the prolonged follow-up. When medical therapies fail, are unavailable or contra-indicated, bilateral adrenalectomy should be indicated as a life-saving measure. Adrenal arterial embolization is rarely encountered in routine clinical practice, being a last alternative in specialized centers when all other options fail or are contra-indicated.

Effects of mitotane on testicular adrenal rest tumors in congenital adrenal hyperplasia due to 21-hydroxylase deficiency: a retrospective series of five patients

We conducted a retrospective study on the long-term effect of mitotane treatment on testicular adrenal rest tumors (TARTs) in five adult patients with classic 21-hydroxylase deficiency. After 60 months of mitotane treatment, a decrease in adrenal steroids was observed in four patients. Testicular ultrasonography showed complete disappearance of TART in two patients, stabilization in two patients and a halving of TART volume in the remaining patient. Sperm count improved notably in two patients who had normal baseline inhibin B levels and small inclusions, thus enabling cryopreservation of the subjects' semen. Four years of follow-up of these two patients after the withdrawal of mitotane showed no recurrence of TART and persistent normal testicular function. In conclusion, mitotane could be used as a last resort in CAH patients in the cases of azoospermia associated with TARTs but normal inhibin B levels, as it can improve long-term endocrine and exocrine testicular function.

Adrenally Directed Medical Therapies for Cushing Syndrome

CONTEXT

Endogenous Cushing syndrome (CS) is characterized by excess cortisol secretion, which is driven by tumorous secretion of corticotropin in the majority of patients. Untreated, CS results in substantial morbidity and mortality. Tumor-directed surgery is generally the first-line therapy for CS. However, hypercortisolism may persist or recur postoperatively; in other cases, the underlying tumor may not be resectable or its location may not be known. Yet other patients may be acutely ill and require stabilization before definitive surgery. In all these cases, additional interventions are needed, including adrenally directed medical therapies.

EVIDENCE ACQUISITION

Electronic literature searches were performed to identify studies pertaining to adrenally acting agents used for CS. Data were abstracted and used to compile this review article.

EVIDENCE SYNTHESIS

Adrenally directed medical therapies inhibit one or several enzymes involved in adrenal steroidogenesis. Several adrenally acting medical therapies for CS are currently available, including ketoconazole, metyrapone, osilodrostat, mitotane, and etomidate. Additional agents are under investigation. Drugs differ with regards to details of their mechanism of action, time course of pharmacologic effect, safety and tolerability, potential for drug-drug interactions, and route of administration. All agents require careful dose titration and patient monitoring to ensure safety and effectiveness, while avoiding hypoadrenalism.

CONCLUSIONS

These medications have an important role in the management of CS, particularly among patients with persistent or recurrent hypercortisolism postoperatively or those who cannot undergo tumor-directed surgery. Use of these drugs mandates adequate patient instruction and close monitoring to ensure treatment goals are being met while untoward adverse effects are minimized.

Predicitve Value of FDG Uptake in the Remaining Adrenal Gland Following Adrenalectomy for Adrenocortical Cancer

Following initial surgery, patients with adrenocortical carcinoma (ACC) are commonly treated with the adrenolytic substance mitotane in an adjuvant or therapeutic setting. Treatment responses, however, are variable. The objective of the study was to investigate a possible correlation between FDG-PET activity of the remaining adrenal gland and therapeutic response of mitotane treatment. This is a retrospective study enrolling patients from two German centers with operated ACC and minimal information on PET-CT scanning. Eighty-two ACC patients after adrenalectomy were included (66 treated with mitotane and 16 without medical therapy). FDG uptake of the contralateral adrenal gland, liver and mediastinum was analyzed from a total of 291 PET/CT scans (median 4 scans per patient) and correlated with clinical annotations including overall and recurrence free survival. The majority of patients (81%) displayed a temporary increase in adrenal FDG uptake within the first 18 months following surgery, which was not associated with a morphological correlate for potential malignancy. This increase was mainly present in patients treated with mitotane (51/61, 84%) but less frequent in the control group (4/7, 57%). No direct correlation with mitotane plasma levels were evident. Patients following R0 resection with high adrenal uptake showed a tendency towards better clinical outcome without reaching a significance value (HR 1.41; CI 0.42-4.75; p=0.059). FDG update of the contralateral adrenal gland may not be misinterpreted as sign of malignancy but might be rather associated with a trend towards better clinical outcome.

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.

Advances in the Medical Treatment of Cushing Disease

Medical therapy has an adjunctive role in management of Cushing disease. Medical therapy is recommended for patients who received pituitary radiotherapy and are awaiting its salutary effects. Medications are used preoperatively to stabilize the condition of seriously ill patients before surgery. Medical therapy is used to control hypercortisolism in patients with uncertain tumor location. Medical therapies available for management of patients with Cushing disease include steroidogenesis inhibitors, centrally acting agents, and glucocorticoid receptor antagonists. All agents require careful monitoring to optimize clinical effectiveness and manage adverse effects. Novel agents in development may expand the armamentarium for management of this condition.

Expression of SOAT1 in Adrenocortical Carcinoma and Response to Mitotane Monotherapy: An ENSAT Multicenter Study

CONTEXT

Objective response rate to mitotane in advanced adrenocortical carcinoma (ACC) is approximately 20%, and adverse drug effects are frequent. To date, there is no marker established that predicts treatment response. Mitotane has been shown to inhibit sterol-O-acyl transferase 1 (SOAT1), which leads to endoplasmic reticulum stress and cell death in ACC cells.

OBJECTIVE

To investigate SOAT1 protein expression as a marker of treatment response to mitotane.

PATIENTS

A total of 231 ACC patients treated with single-agent mitotane as adjuvant (n = 158) or advanced disease therapy (n = 73) from 12 ENSAT centers were included. SOAT1 protein expression was determined by immunohistochemistry on formalin-fixed paraffin-embedded specimens.

SETTING

Retrospective study at 12 ACC referral centers.

MAIN OUTCOME MEASURE

Recurrence-free survival (RFS), progression-free survival (PFS), and disease-specific survival (DSS).

RESULTS

Sixty-one of 135 patients (45%) with adjuvant mitotane treatment had recurrences and 45/68 patients (66%) with mitotane treatment for advanced disease had progressive disease. After multivariate adjustment for sex, age, hormone secretion, tumor stage, and Ki67 index, RFS (hazard ratio [HR] = 1.07; 95% confidence interval [CI], 0.61-1.85; P = 0.82), and DSS (HR = 1.30; 95% CI, 0.58-2.93; P = 0.53) in adjuvantly treated ACC patients did not differ significantly between tumors with high and low SOAT1 expression. Similarly, in the advanced stage setting, PFS (HR = 1.34; 95% CI, 0.63-2.84; P = 0.45) and DSS (HR = 0.72; 95% CI, 0.31-1.70; P = 0.45) were comparable and response rates not significantly different.

CONCLUSIONS

SOAT1 expression was not correlated with clinical endpoints RFS, PFS, and DSS in ACC patients with mitotane monotherapy. Other factors appear to be relevant for mitotane treatment response and ACC patient survival.

Liver X receptor inhibition potentiates mitotane-induced adrenotoxicity in ACC

Adrenocortical carcinoma (ACC) is a rare aggressive malignancy with a poor outcome largely due to limited treatment options. Here, we propose a novel therapeutic approach through modulating intracellular free cholesterol via the liver X receptor alpha (LXRα) in combination with current first-line pharmacotherapy, mitotane. H295R and MUC-1 ACC cell lines were pretreated with LXRα inhibitors in combination with mitotane. In H295R, mitotane (20, 40 and 50 µM) induced dose-dependent cell death; however, in MUC-1, this only occurred at a supratherapeutic concentration (200 µM). LXRα inhibition potentiated mitotane-induced cytotoxicity in both cell lines. This was confirmed through use of the CompuSyn model which showed moderate pharmacological synergism and was indicative of apoptotic cell death via an increase in annexinV and cleaved-caspase 3 expression. Inhibition of LXRα was confirmed through downregulation of cholesterol efflux pumps ABCA1 and ABCG1; however, combination treatment with mitotane attenuated this effect. Intracellular free-cholesterol levels were associated with increased cytotoxicity in H295R (r2 = 0.5210) and MUC-1 (r2 = 0.9299) cells. While both cell lines exhibited similar levels of free cholesterol at baseline, H295R were cholesterol ester rich, whereas MUC-1 were cholesterol ester poor. We highlight the importance of LXRα mediated cholesterol metabolism in the management of ACC, drawing attention to its role in the therapeutics of mitotane sensitive tumours. We also demonstrate significant differences in cholesterol storage between mitotane sensitive and resistant disease.

What is the role of medical therapy in adrenal-dependent Cushing's syndrome?

Medical therapy to control hypercortisolism in adrenal Cushing's syndrome is currently not the first-line therapy. However, in many clinical scenarios like pre-surgical treatment, in patients who are not suitable candidates for surgery or in patients with bilateral hyperplasia, medical therapy can be important representing the only viable treatment option. Adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers have been used for many years: metyrapone, ketoconazole and mifepristone are in current use and effective. Mitotane can be used as well but is considered second-line therapy because of its high toxicity. Etomidate has a special position as emergency medication in severe hypercortisolism. New drugs are tested in prospective trials (levoketoconazole, osilidrostat and relacorilant) and might become effective alternatives to common drugs. Oher drugs - adrenal steroidogenesis inhibitors as well as glucocorticoid receptor antagonists - are currently tested in vitro.

New perspectives for mitotane treatment of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an aggressive cancer characterized by poor survival. Apart from radical surgery, there is a limited range of therapeutic options and mitotane remains the cornerstone of medical treatment of ACC in either adjuvant or palliative settings. The aim of adjuvant mitotane therapy is to reduce the risk of ACC recurrence following surgical removal of the tumor. Use of mitotane in an adjuvant setting is off-label, but the recent guidelines endorsed by the European Society of Endocrinology (ESE) and the European Network for the Study of Adrenal Tumors (ENSAT) recommend it in ACC patients at high risk of recurrence. The palliative use of mitotane for treatment of advanced ACC aims at controlling tumor progression and, when present, hormone secretion. In this clinical setting, mitotane is used in association with chemotherapy to treat the more aggressive forms, while mitotane monotherapy is reserved for less progressive ACC. Many years after its introduction in clinical practice, there are still uncertainties surrounding the use of this old drug and the derived benefits. Moreover, physicians who use mitotane should recognize and manage the systemic effects of the drug that need a complex supporting therapy.

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.

A clinical study and treatment results of adrenocortical carcinoma patients presented in Shaukat Khanum Memorial Cancer Hospital and Research Center, Lahore

Adrenocortical carcinoma is a rare and aggressive malignancy with an incidence of 0.5-2 per million per year and its overall prognosis is very poor. This study was aimed to point out the factors associated with tumour recurrence and patient's survival after complete surgical resection of this aggressive malignancy. Patients admitted from January 2011 till December 2015 were retrospectively reviewed using case notes. In these five years 29 patients were admitted with adrenal tumour out of which 13 had adrenocortical carcinoma. On five year follow up, six (46.2%) patients developed recurrence. MEAN disease free survival was 31.0 ± 23.92 (2-63) months 53.8% while MEAN overall survival was 46.69 ± 22.81 (14-80) months 92.3%. Results concluded that hormonally active tumour on clinical presentation, positive surgical resection margins, positive nodal status and poorly differentiated tumour on histopathology are the factors associated with tumour recurrence and patient's survival.

In vitro antitumor activity of progesterone in human adrenocortical carcinoma

PURPOSE

The management of patients with adrenocortical carcinoma (ACC) is challenging. As mitotane and chemotherapy show limited efficacy, there is an urgent need to develop therapeutic approaches. The aim of this study was to investigate the antitumor activity of progesterone and explore the molecular mechanisms underlying its cytotoxic effects in the NCI-H295R cell line and primary cell cultures derived from ACC patients.

METHODS

Cell viability, cell cycle, and apoptosis were analyzed in untreated and progesterone-treated ACC cells. The ability of progesterone to affect the Wnt/β-catenin pathway in NCI-H295R cells was investigated by immunofluorescence. Progesterone and mitotane combination experiments were also performed to evaluate their interaction on NCI-H295R cell viability.

RESULTS

We demonstrated that progesterone exerted a concentration-dependent inhibition of ACC cell viability. Apoptosis was the main mechanism, as demonstrated by a significant increase of apoptosis and cleaved-Caspase-3 levels. Reduction of β-catenin nuclear translocation may contribute to the progesterone cytotoxic effect. The progesterone antineoplastic activity was synergically increased when mitotane was added to the cell culture medium.

CONCLUSIONS

Our results show that progesterone has antineoplastic activity in ACC cells. The synergistic cytotoxic activity of progesterone with mitotane provides the rationale for testing this combination in a clinical study.

Hsp90 inhibition in adrenocortical carcinoma: Limited drug synergism with mitotane

90 kDa heat shock proteins (Hsp90) act as protein chaperones and play a role in modulating endoplasmic reticulum (ER) stress. Hsp90 inhibitors are under clinical investigation as cancer treatment. Mitotane therapy of adrenocortical carcinoma (ACC) has been shown to act through lipid-induced ER-stress. To explore the potential of Hsp90 inhibitors in ACC as a single agent and in combination with mitotane, we analyzed two independent gene expression data sets of adrenal tumors in silico and treated the ACC cell line model NCI-H295 with Hsp90 inhibitors BIIB021 (B) and CCT18159 (C) alone and in combination with mitotane. ER-stress markers were monitored by immunoblotting. Drug synergism was quantified using the median effect model with cell viability as read-out. Cytosolic Hsp90 isoforms AA1 and AB1 were significantly overexpressed in ACC. Viability of H295 cells was impaired by B and C as single agents with an EC₅₀ of 5.7 × 10^-6M and 12.1 × 10^-6M. B but not C dose-dependently increased XBP1 splicing and CHOP expression indicative of ER-stress activation. ER-stress marker expression was enhanced by co-incubation of B with 10  μM but not 5  μM mitotane. Maximal CHOP expression was induced by 25 μM mitotane alone with no additional effect of B. Combination indices (CI) of B and C with mitotane ranged from 0.64 to 1.38 and 0.68 to 1.30, respectively where CI values < 0.5 support clinically-relevant drug synergism. In conclusion, Hsp90 paralogs are differentially expressed in ACC and B but not C activates ER-stress in ACC cells. No meaningful drug synergism of Hsp90 inhibitors with mitotane was observed.

Primary malignant tumors of the adrenal glands

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

Effectiveness of medical treatment for Cushing's syndrome: a systematic review and meta-analysis

PURPOSE

To systematically review the effectiveness of medical treatment for Cushing's syndrome in clinical practice, regarding cortisol secretion, clinical symptom improvement, and quality of life. To assess the occurrence of side effects of these medical therapies.

METHODS

Eight electronic databases were searched in March 2017 to identify potentially relevant articles. Randomized controlled trials and cohort studies assessing the effectiveness of medical treatment in patients with Cushing's syndrome, were eligible. Pooled proportions were reported including 95% confidence intervals.

RESULTS

We included 35 articles with in total 1520 patients in this meta-analysis. Most included patients had Cushing's disease. Pooled reported percentage of patients with normalization of cortisol ranged from 35.7% for cabergoline to 81.8% for mitotane in Cushing's disease. Patients using medication monotherapy showed a lower percentage of cortisol normalization compared to use of multiple medical agents (49.4 vs. 65.7%); this was even higher for patients with concurrent or previous radiotherapy (83.6%). Mild side effects were reported in 39.9%, and severe side effects were seen in 15.2% of patients after medical treatment. No meta-analyses were performed for clinical symptom improvement or quality of life due to lack of sufficient data.

CONCLUSIONS

This meta-analysis shows that medication induces cortisol normalization effectively in a large percentage of patients. Medical treatment for Cushing's disease patients is thus a reasonable option in case of a contraindication for surgery, a recurrence, or in patients choosing not to have surgery. When experiencing side effects or no treatment effect, an alternate medical therapy or combination therapy can be considered.

Enzyme autoinduction by mitotane supported by population pharmacokinetic modelling in a large cohort of adrenocortical carcinoma patients

OBJECTIVE

Mitotane is used for the treatment of adrenocortical carcinoma. High oral daily doses of typically 1- 6 g are required to attain therapeutic concentrations. The drug has a narrow therapeutic index and patient management is difficult because of a high volume of distribution, very long elimination half-life, and drug interaction through induction of metabolizing enzymes. The present evaluation aimed at the development of a population pharmacokinetic model of mitotane to facilitate therapeutic drug monitoring.

METHODS

Appropriate dosing information, plasma concentrations (1137 data points) and covariates were available from therapeutic drug monitoring (TDM) of 76 adrenocortical carcinoma patients treated with mitotane. Using nonlinear mixed effects modeling, a simple structural model was first developed, with subsequent introduction of metabolic autoinduction. Covariate data were analyzed to improve overall model predictability. Simulations were performed to assess the attainment of therapeutic concentrations with clinical dosing schedules.

RESULTS

A one-compartment pharmacokinetic model with first order absorption was found suitable to describe the data, with an estimated central volume of distribution of 6086 L related to a high interindividual variability of 81.5%. Increase in clearance of mitotane during treatment could be modeled by a linear enzyme autoinduction process. Body mass index was found to have an influence upon disposition kinetics of mitotane. Model simulations favor a high dose regimen to rapidly attain therapeutic concentrations, with the first TDM suggested on day 16 of treatment to avoid systemic toxicity.

CONCLUSION

The proposed model describes mitotane pharmacokinetics and can be used to facilitate therapy by predicting plasma concentrations.

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.

Prognostic factors in adrenocortical carcinoma: data from a large Polish series

Introduction Adrenocortical carcinoma (ACC) is a rare malignancy, associated with poor outcome and few therapeutic options. Despite increasing attention, the knowledge about the clinical course and treatment of these tumors is limited. Objectives Survival rates in ACC are still low and the percentage of relapse is high. Thus, it is crucial to identify the prognostic factors of overall survival (OS) and recurrence‑free survival (RFS). Patients and methods This was a retrospective analysis of 66 patients diagnosed with ACC between 2002 and 2015. Results The median OS was 43.5 months, 78.19 months for stage I + II, 22.95 months for stage III, and 19.54 months for stage IV ACC. Older age, stage IV ACC, margin status R2, and no mitotane treatment were associated with poor OS. Low Ki67 and mitotic indices were related to improved OS in a univariate analysis. The median RFS was 101.1 months. Disease recurrence after potentially curative surgery was reported in 1 patient (25%) with stage I, 12 patients (46%) with stage II, and 9 patients (45%) with stage III ACC. Male sex and no mitotane treatment were associated with a reduced RFS in a multivariate analysis and higher Ki67 and mitotic indices in the univariate analysis. Conclusions Ki67 and mitotic indices should be considered as prognostic factors when planning the adjuvant treatment of ACC. Mitotane treatment may be independently associated with better outcomes regardless of the tumor stage.

Favorable Response of Metastatic Adrenocortical Carcinoma to Etoposide, Adriamycin and Cisplatin (EAP) Chemotherapy. Report of two Cases

The usefulness of non-specific chemotherapy for advanced adrenocortical carcinoma (ACC) Is controversial. We report on 2 young female patients (25 and 19 yr) who presented with a clinical picture of Cushing's syndrome due to histologically confirmed ACC. The first patient underwent radical surgery, but after a disease-free interval of 6 months a local recurrence was apparent. She was reoperated and treated with 6 courses of cisplatin and etoposide chemotherapy. Mitotane (8 g daily) was begun, but 2 months later debulking surgery was again performed. A second-line chemotherapy with the etoposide, adriamycin, cisplatin (EAP) scheme attained a partial remission lasting 7 months, then metastatic spread to the brain led to death of the patient. The survival time was 30 months. The second patient underwent radical surgery and adjuvant mitotane (4 g daily), but multiple lung and mediastinal metastases were diagnosed after an interval of 29 months. Chemotherapy with the EAP regimen (6 courses) without interrupting mitotane attained a partial remission lasting 21+ months. We suggest that the EAP scheme is active in advanced ACC and that Its association with mitotane is feasible.

Mitotane Monotherapy in Patients With Advanced Adrenocortical Carcinoma

CONTEXT

Although mitotane is the only approved drug for the treatment of adrenocortical carcinoma (ACC), data on monotherapy in advanced disease are still scarce.

OBJECTIVE

To assess the efficacy of mitotane in advanced ACC in a contemporary setting and to identify predictive factors.

DESIGN AND SETTING

Multicenter cohort study of three German referral centers.

PATIENTS

One hundred twenty-seven patients with advanced ACC treated with mitotane monotherapy.

OUTCOME MEASURES

Response Evaluation Criteria in Solid Tumors evaluation, progression-free survival (PFS) and overall survival (OS) by Kaplan-Meier method, and predictive factors by Cox regression.

RESULTS

Twenty-six patients (20.5%) experienced objective response, including three with complete remission. Overall, median PFS was 4.1 months (range 1.0 to 73) and median OS 18.5 months (range 1.3 to 220). Multivariate analysis indicated two main predictive factors: low tumor burden (<10 tumoral lesions), hazard ratio (HR) for progression of 0.51 (P = 0.002) and for death of 0.59 (P = 0.017); and initiation of mitotane at delayed advanced recurrence, HR 0.35(P < 0.001) and 0.34 (P < 0.001), respectively. Accordingly, 67% of patients with low tumor burden and mitotane initiation ≥360 days after primary diagnosis experienced a clinical benefit (stable disease >180 days). Patients who achieved mitotane levels >14 mg/L had significantly longer OS (HR 0.42; P = 0.003).

CONCLUSIONS

At 20.5% the objective response rate was slightly lower than previously reported. However, >20% of patients experienced long-term disease control at >1 year. In general, patients with late diagnosis of advanced disease and low tumor burden might especially benefit from mitotane monotherapy, whereas patients with early advanced disease and high tumor burden are probably better candidates for combined therapy of mitotane and cytotoxic drugs.

Mitotane treatment in patients with metastatic testicular Leydig cell tumor associated with severe androgen excess

Mitotane (o,p'DDD) is established in the adjuvant and advanced-stage treatment of adrenocortical carcinoma and counteracts both tumor growth and tumor-related steroid production. Both the adrenal glands and the gonads are steroidogenically active organs and share a common embryogenic origin. Here, we describe the effects of mitotane in two patients with metastatic Leydig cell tumor (LCT) of the testes and associated severe androgen excess (serum testosterone 93 and 88 nmol/L, respectively; male reference range 7-27 nmol/L). Both men suffered from severe restlessness, insomnia and irritability, which they described as intolerable and disrupting normal life activities. Urinary steroid profiling by gas chromatography-mass spectrometry (GC-MS) confirmed excess androgen production and revealed concurrent overproduction of glucocorticoids and glucocorticoid precursors, which under physiological conditions are produced only by the adrenal glands but not by the gonads. In a palliative approach, they were commenced on mitotane, which achieved swift control of the hormone excess and the debilitating clinical symptoms, restoring normal quality of life. GC-MS demonstrated normalization of steroid production and decreased 5α-reductase activity, resulting in decreased androgen activation, and imaging demonstrated disease stabilization for 4-10 months. In conclusion, mitotane can be highly effective in controlling steroid excess in metastatic LCTs, with anti-tumor activity in some cases.