Adrenocortical carcinomas: surgical trends and results of a 253-patient series from the French Association of Endocrine Surgeons study group

Curative Resection of Adrenocortical Carcinoma: Rates and Patterns of Postoperative Recurrence

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare malignancy. The aim of this study was to determine the incidence and patterns of recurrence after curative-intent surgery for ACC.

METHODS

Patients who underwent curative-intent resection for ACC between 1993 and 2014 were identified from 13 academic institutions participating in the United States ACC study group. Patients with metastasis or an R2 margin were excluded. Patterns and rates of recurrence were determined and classified as locoregional and distant recurrence.

RESULTS

A total of 180 patients with a median age of 52 years (interquartile range 43-61) were identified. Most patients underwent open surgery (n = 111, 64.5 %) and had an R0 resection margin (n = 117, 75.0 %). At last follow-up, 116 patients (64.4 %) had experienced recurrence (locoregional only, n = 41, 36.3 %; distant only, n = 51, 45.1 %; locoregional and distant, n = 21, 18.6 %). Median time to recurrence was 18.8 months. Several factors were associated with locoregional recurrence, including left-sided ACC location (odds ratio [OR] 2.71, 95 % confidence interval [CI] 1.06-6.89) and T3/T4 disease (reference T1/T2, OR 3.04, 95 % CI 1.19-7.80) (both p < 0.05). Distant recurrence was associated with larger tumor size (OR 1.11, 95 % CI 1.01-1.24) and T3/T4 disease (reference T1/T2, OR 5.23, 95 % CI 1.70-16.10) (both p < 0.05). Patients with combined locoregional and distant recurrence had worse survival (3- and 5-year survival: 39.5, 19.7 %) versus patients with distant-only (3- and 5-year survival 55.1, 43.3 %) or locoregional-only recurrence (3- and 5-year survival 81.4, 64.1 %) (p = 0.01).

CONCLUSIONS

Nearly two-thirds of patients experienced disease recurrence after resection of ACC. Although a subset of patients experienced recurrence with locoregional disease only, many patients experienced recurrence with distant disease as a component of recurrence and had a poor prognosis.

Clinicopathological Features of Adrenal Tumors: a Ten-year Study in Yazd, Iran

BACKGROUND

Adrenal tumors are relatively uncommon, and have different presentations, so we decided to evaluate the clinico-pathological characteristics of benign and malignant tumors in a ten-year period.

MATERIALS AND METHODS

This cross sectional-analytical study was conducted on adrenal resection samples taken during 2004-2014 in three hospitals in Yazd province. Data were analyzed using SPSS software, version 17. Chi-square and Fisher's exact test were used as appropriate Results: A total of 71 patients with adrenal tumors were analyzed, including 32 (45.1%) men and 39 (54.9%) women with an overall mean age 37.7±19.9 (range: 6-75 years). Some 50.7% of lesions were benign and 49.3% were malignant. Neuroblastoma was the most malignant lesion (32.3%) followed by adrenocortical carcinoma (8.4%). Among the benign lesions pheochromocytoma was the most common (25.3%) followed by adrenocortical adenoma (12.6%). While 64% of tumors were functional 36% were non functional. Significant correlation was seen between the age of patient and type of tumor (P=0.001). In patients between 14-40 years old no malignant lesions was found, although under 14 years old all of the tumors were malignant. Malignant lesions mostly presented with abdominal pain, abdominal mass and anorexia (57.2%, 45.7% and 45.7%) respectively. Benign lesions mostly presented with paroxysmal hypertension, headache and abdominal pain (61.2%, 47.2% and 44.4%) respectively.

CONCLUSIONS

Since the trend of adrenal tumors is on the rise based on this and other studies, suspected cases should undergo prompt hormonal and radiological assessment. Early diagnosis and treatment could prevent tumor progression and reduce mortality and morbidity rates.

What is the appropriate role of minimally invasive vs. open surgery for small adrenocortical cancers?

PURPOSE OF REVIEW

The role of endoscopic adrenalectomy for adrenocortical carcinoma is the most controversial and debated points in adrenal surgery. We reviewed the most recent literature on this topic.

RECENT FINDINGS

From the amount of available data (even if not conclusive), the following could be extrapolated: first, for patients with apparently localized disease the adrenal gland should be removed en bloc with the entire retroperitoneal fat pad, which also includes some periadrenal lymph nodes, but no extended resection is necessary in absence of involvement of adjacent structures; second, in experienced centers, oncologic outcome for endoscopic adrenalectomy is not inferior to open adrenalectomy when strict selection criteria and the principles of oncologic surgery are respected. When performed by nonexperienced surgeons, endoscopic adrenalectomy may be associated with a higher rate of positive margin and local recurrence; third, patients observed at specialized referral centers receive a more accurate preoperative workup that allows a better operative planning and a more comprehensive postoperative treatment.

SUMMARY

Although waiting for further more exhaustive studies, we think that for suspected adrenocortical carcinoma, smaller than 8-10 cm and without pre or intraoperative evidence of local invasion, endoscopic adrenalectomy in a referral center seems to be an acceptable option.

Giant adrenal tumor presenting as Cushing's syndrome and pheochromocytoma: A case report

We report a case of a 35-year-old lady who presented with Cushingoid features and associated raised urinary metanephrine. The patient underwent open adrenelectomy. Histopathological examination revealed adreno-cortical carcinoma with microscopic lymphovascular invasion. Postoperative period was uneventful and is on follow-up for the last one year and is doing well.

Adrenocortical carcinoma (ACC): diagnosis, prognosis, and treatment

Adrenocortical carticnoma (ACC) is a rare malignancy with an incidence of 0.7-2.0 cases/million habitants/year. The diagnosis of malignancy relies on careful investigations of clinical, biological, and imaging features before surgery and pathological examination after tumor removal. Most patients present with steroid hormone excess or abdominal mass effects, but 15% of patients with ACC is initially diagnosed incidentally. After the diagnosis, in order to assess the ACC prognosis and establish an adequate basis for treatment decisions different tools are proposed. The stage classification proposed by the European Network for the Study of Adrenal Tumors (ENSAT) is recommended. Pathology reports define the Weiss score, the resection status and the proliferative index, including the mitotic count and the Ki67 index. As far as the treatment is concerned, in case of tumor limited to the adrenal gland, the complete resection of the tumor is the first option. Most patients benefit from adjuvant mitotane treatment. In metastatic disease, mitotane is the cornerstone of initial treatment, and cytotoxic drugs should be added in case of progression. Recently, the First International Randomized (FIRM-ACT) Trial in metastatic ACC reported the association between mitotane and etoposide/doxorubicin/cisplatin (EDP) as the new standard in first line treatment of ACC. In last years, new targeted therapies, including the IGF-1 receptor inhibitors, have been investigated, but their efficacy remains limited. Thus, new treatment concepts are urgently needed. The ongoing "omic approaches" and next-generation sequencing will improve our understanding of the pathogenesis and hopefully will lead to better therapies.

Adrenocortical carcinoma

Recent developments in the treatment of adrenocortical carcinoma (ACC) include diagnostic and prognostic risk stratification algorithms, increasing evidence of the impact of historical therapies on overall survival, and emerging targets from integrated epigenomic and genomic analyses. Advances include proper clinical and molecular characterization of all patients with ACC, standardization of proliferative index analyses, referral of these patients to large cancer referral centers at the time of first surgery, and development of new trials in patients with well-characterized ACC. Networking and progress in the molecular characterization of ACC constitute the basis for significant future therapeutic breakthroughs.

Surgical management of adrenocortical carcinoma

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

Survival and prognostic factors for adrenocortical carcinoma: a single institution experience

Background

Adrenocortical carcinoma (ACC) is aggressive, but rare tumours that have not been sufficiently studied. The aim of our study was to present the demographic and clinical characteristics of patients with ACC, to determine the overall survival rates, analyse the effect of prognostic factors on survival, as well as to identify favorable and unfavourable predictors of survival.

Method

The study included 72 patients (42 women and 30 men) with ACC. We analysed the prognostic value of the demographic and clinical characteristics of the patients, tumour characteristics, therapy administered and survival rates. Kaplan-Meier survival curves and the log-rank test were used to estimate the overall and specific survival probabilities and the Cox regression model was used to identify independent prognostic factors for survival.

Results

The patients had mean age of 50 years. The 1-, 5-, and 10-year probabilities of survival in patients with ACC were 52.5 %, 41.1 %, and 16.4 %, respectively. The median survival time was 36 months. The results of multivariate Cox regression analysis showed that the presence of lymphatic metastases (HR = 7.37, 95 % CI = 2.31-23.48, p = 0.001) and therapy with mitotane (HR = 0.11, 95 % CI = 0.04-0.27, p = 0.001) were independent prognostic factors for survival.

Conclusion

The presence of lymphatic metastasis is an unfavourable prognostic factor, while postoperative therapy with mitotane is a favorable prognostic factor for survival in patients with ACC.

Diagnostic and prognostic features in adrenocortical carcinoma: a single institution case series and review of the literature

Background

Adrenocortical carcinoma is a rare cancer, with an incidence in the literature of 0.5 to 2 cases per million population per year. Adult adrenocortical carcinoma has a poor prognosis, underscoring the importance of identifying diagnostic and prognostic markers.

Methods

We searched our laboratory database for all cases in the past 15 years with a diagnosis of adrenocortical carcinoma. The original slides were then reviewed for their histopathological features. A representative paraffin block was subjected to further immunohistochemical staining for Ki-67, inhibin, steroidogenic factor-1 (SF-1), p53, and Β-catenin. These slides were scored by the study pathologist who was blinded to all clinicopathological data. In addition, a comprehensive review of the relevant English literature in the past 15 years was conducted.

Results

Eight cases were identified, including two adrenal sarcomatoid carcinomas. Seven of the eight cases had a disrupted reticulin network. Six of the eight tumors had >10% Ki-67 expression. Five of the eight tumors had >10% p53 expression. Positive inhibin immunohistochemical staining was seen in three of the eight tumors, and positive SF-1 staining was seen in five of the seven stained tumors. Abnormal Β-catenin intracellular accumulation was noted in four of the eight tumors. The two tumors in our series with sarcomatoid histology did not stain positively for SF-1 or inhibin.

Conclusions

Eight cases of adrenocortical carcinoma, including two with sarcomatoid features are presented. The two sarcomatoid adrenocortical carcinomas in our series did not stain for SF-1 which suggests a possible de novo pathway of tumorigenesis for this rare variant. The reticulin staining method was a useful tool for rapid differentiation of adrenocortical adenomas and carcinomas. Diffuse p53 staining showed a trend for positive correlation with increased Ki-67 expression. Inhibin staining was inconsistently expressed in our cases of adrenocortical carcinoma. In conclusion, as adrenocortical carcinoma is a rare disease, we recommend future multicenter studies with appropriate sample sizes to further evaluate the efficacy of these diagnostic and prognostic markers.

Repeated resections for liver metastasis from primary adrenocortical carcinoma: A case report

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Adrenal cortical carcinoma (ACC) is rare, often recurring, and has a poor prognosis.

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Surgery remains the optimal treatment for ACC, due to chemotherapy’s ineffectiveness.

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Our patient developed 2 liver metastases after right adrenalectomy (1.5 and 4 years).

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Therefore, complete surgical resection should be considered in similar cases.

Introduction

Adrenal cortical carcinoma (ACC) is a very rare type of tumor that generally has a poor prognosis. Little has been reported on repeated liver resections with recurrent metastasis still confined to the liver. In this report, we describe a case of functioning ACC in a 65-year-old woman with 2 liver metastases of the ACC (at 1.5 and 4 years) after the right adrenalectomy.

Presentation of case

A 65-year-old woman was referred to our hospital based on a suspicion of hyperaldosteronism. Abdominal computed tomography revealed a lesion at the right adrenal gland; therefore, we performed right adrenalectomy and subsequently diagnosed the lesion as ACC. However, follow-up computed tomography at 1.5 and 4 years after the right adrenalectomy revealed liver metastasis of ACC; liver resection was performed for both metastases.

Discussion

Complete surgical resection is the established approach for the treatment of ACC. The prognosis of ACC is usually dismal, and recurrence rates of up to 85% have been reported. However, the appropriate treatment for recurrent ACC is not well established, and the effectiveness of other modalities, such as chemotherapy and radiotherapy, is not proven. Therefore, surgical resection may currently be the most appropriate treatment modality, as the patient achieved a disease-free interval of 2.5 years after the first liver resection.

Conclusion

In selected patients with recurrent or metastatic ACC, resection is likely to be associated with prolonged survival. However, a full cure is generally not achievable, and a multidisciplinary approach is likely needed to achieve long-term disease-free status and survival.

Giant nonfunctioning adrenocortical carcinoma: a case report and review of the literature

BACKGROUND

Adrenocortical carcinoma is a rare and aggressive malignancy. Patients usually present early with manifestation of abnormal hormone secretion. However, adrenocortical carcinoma can also be nonfunctioning, and such patients present late with a mass effect or distant metastases.

CASE PRESENTATION

We herein report a case of a 30-year-old Sri-Lankan woman who presented with a 3-month history of left flank pain associated with nausea, vomiting, and weight loss. Imaging revealed a large left upper quadrant mass with a 1.8-cm left lung nodule. The differential diagnoses included a left adrenal mass, left upper pole renal mass, and retroperitoneal sarcoma. A functional adrenal work-up revealed no abnormal findings. Surgical excision of the mass was uneventful with no postoperative complications. Pathological analysis revealed a nonfunctioning adrenocortical carcinoma measuring 16 × 14 × 10 cm. To our knowledge, a mass of this size is among the largest nonfunctioning adrenocortical carcinomas reported in the published literature. The investigations and approach to treatment were consistent with those in the published literature.

CONCLUSION

Large nonfunctioning adrenocortical carcinomas pose a diagnostic and therapeutic challenge, and most are diagnosed at a late stage. Appropriate imaging and functional work-up of the mass are vital before treatment. Surgical excision is safe, even for large adrenocortical carcinomas; excision in patients with advanced disease has been shown to have the best outcomes.

Rare incidence of primary adrenocortical carcinosarcoma: A case report and literature review

Adrenocortical carcinoma (ACC) is a rare, but highly aggressive type of tumor with an incidence of one to two per million annually. Adrenocortical carcinosarcoma is an exceptional variant of ACC, which is characterized by the presence of histological regions of carcinoma and sarcoma. To date, to the best of our knowledge, there have only been 12 reported cases of adrenocortical carcinosarcoma. In the present study, a case of primary, non-functional adrenocortical carcinosarcoma is described, as well as a review of the literature to raise awareness of this particularly rare type of malignant neoplasm that is associated with a worse diagnosis and prognosis than adrenocortical carcinoma. In the present study, the patient underwent a laparoscopic left adrenalectomy and the tumor was dissected without complication from the left kidney. Microscopic observations showed the tumor comprised of epithelial and spindle cell components. The patient did not exhibit signs of tumor recurrence at the one-month follow-up. The potential diagnosis of adrenocortical carcinosarcoma must be considered when diagnosing adrenal malignancies in adults. In addition, comphrensive imunohistochemical staining may be required to identify possible sarcomatous patterns. To the best of our knowledge, the present case is the first to report an incidence of adrenocortical carcinosarcoma in China. Details of the patient are presented and the pathology of adrenocortical carcinosarcoma is discussed.

Pediatric adrenocortical tumors: diagnosis, management and advancements in the understanding of the genetic basis and therapeutic implications

Adrenocortical tumors (ACTs) may be sporadic or related to inherited genetic syndromes. Uncovering the molecular defects underlying these genetic syndromes has revealed key signaling pathways involved in adrenocortical tumorigenesis. Although the understanding of ACT biology has improved, to date, very few potential prognostic molecular markers of childhood ACTs have been identified. In this review, we summarize the current knowledge of the epidemiology, clinical presentation, diagnosis, prognosis and treatment options for pediatric patients with ACTs. A review of the genetic basis of adrenocortical tumorigenesis is presented, focusing on the main molecular abnormalities involved in the tumorigenic process and potential novel therapy targets that have been generated, or are being generated, with the discovery of these molecular defects.

Aldosterone and cortisol co-secreting bifunctional adrenal cortical carcinoma: A rare event

Adrenocortical carcinoma (ACC) co-secreting aldosterone and cortisol is extremely rare. We report the case of a 37-yearold female who presented with paresis and facial puffiness. Evaluation revealed hypertension, hyperglycemia, severe hypokalemia and hyperaldosteronemia with elevated plasma aldosterone to renin ratio (ARR). Urinary free cortisol estimation showed elevated levels. Computed tomography scan revealed a right adrenal mass. Radical adrenalectomy specimen revealed ACC (T3N1). Post-operatively, the patient became normotensive and euglycemic with normalization of urinary cortisol and ARR. This case highlights the need for a complete evaluation in patients of hyperaldosteronism if overlapping symptoms of hypercortisolism are encountered, to avoid post-operative adrenal crisis.

Adrenocortical carcinoma in pregnancy: A diagnostic dilemma

Adrenocortical carcinoma is a rare disease. Additionally, in the case of coexisting pregnancy, there are diagnostic difficulties due to associated physiological hormonal changes as well as imaging limitations. Cushing's syndrome and virilization during pregnancy is a rare entity with few cases reported in the literature. Misdiagnosis is common as the syndrome may be easily confused with preeclampsia or gestational diabetes. We present the case of a 31-year-old pregnant woman with rapidly developing symptoms related to hormonally active adrenocortical cancer.

Surgical resection of synchronously metastatic adrenocortical cancer

INTRODUCTION

Metastatic adrenocortical carcinoma (ACC) is rapidly fatal, with few options for treatment. Patients with metachronous recurrence may benefit from surgical resection. The survival benefit in patients with hematogenous metastasis at initial presentation is unknown.

METHODS

A review of all patients undergoing surgery (European Network for the Study of Adrenal Tumors) stage IV ACC between January 2000 and December 2012 from two referral centers was performed. Kaplan-Meier estimates were analyzed for disease-free and overall survival (OS).

RESULTS

We identified 27 patients undergoing surgery for stage IV ACC. Metastases were present in the lung (19), liver (11), and brain (1). A complete resection (R0) was achieved in 11 patients. The median OS was improved in patients undergoing R0 versus R2 resection (860 vs. 390 days; p = 0.02). The 1- and 2-year OS was also improved in patients undergoing R0 versus R2 resection (69.9 %, 46.9 % vs. 53.0 %, 22.1 %; p = 0.02). Patients undergoing neoadjuvant therapy (eight patients) had a trend towards improved survival at 1, 2, and 5 years versus no neoadjuvant therapy (18 patients) [83.3 %, 62.5 %, 41.7 % vs. 56.8 %, 26.6 %, 8.9 %; p = 0.1]. Adjuvant therapy was associated with improved recurrence-free survival at 6 months and 1 year (67 %, 33 % vs. 40 %, 20 %; p = 0.04) but not improved OS (p = 0.63). Sex (p = 0.13), age (p = 0.95), and location of metastasis (lung, p = 0.51; liver, p = 0.67) did not correlate with OS after operative intervention. Symptoms of hormonal excess improved in 86 % of patients.

CONCLUSION

Operative intervention, especially when an R0 resection can be achieved, following systemic therapy may improve outcomes, including OS, in select patients with stage IV ACC. Response to neoadjuvant chemotherapy may be of use in defining which patients may benefit from surgical intervention. Adjuvant therapy was associated with decreased recurrence but did not improve OS.

The combination of insulin-like growth factor receptor 1 (IGF1R) antibody cixutumumab and mitotane as a first-line therapy for patients with recurrent/metastatic adrenocortical carcinoma: a multi-institutional NCI-sponsored trial

Adrenocortical carcinoma (ACC) is an aggressive malignancy, which lacks an effective systemic treatment. Abnormal activation of insulin-like growth factor receptor 1 (IGF1R) has been frequently observed. Preclinical studies demonstrated that pharmacological inhibition of IGF1R signaling in ACC has antiproliferative effects. A previous phase I trial with an IGF1R inhibitor has demonstrated biological activity against ACC. The objective of this study is to assess the efficacy of the combination of the IGF1R inhibitor cixutumumab (IMC-A12) in association with mitotane as a first-line treatment for advanced/metastatic ACC. We conducted a multicenter, randomized double-arm phase II trial in patients with irresectable recurrent/metastatic ACC. The original protocol included two treatment groups: IMC-A12 + mitotane and mitotane as a single agent, after an initial single-arm phase for safety evaluation with IMC-A12 + mitotane. IMC-A12 was dosed at 10 mg/kg intravenously every 2 weeks. The starting dose for mitotane was 2 g daily, subsequently adjusted according to serum levels/symptoms. The primary endpoint was progression-free survival (PFS) according to RECIST (Response Evaluation Criteria in Solid Tumors). This study was terminated before the randomization phase due to slow accrual and limited efficacy. Twenty patients (13 males, 7 females) with a median age of 50.2 years (range 21.9-79.6) were enrolled for the single-arm phase. Therapeutic effects were observed in 8/20 patients, including one partial response and seven stable diseases. The median PFS was 6 weeks (range 2.66-48). Toxic events included two grade 4 (hyperglycemia and hyponatremia) and one grade 5 (multiorgan failure). Although the regimen demonstrated activity in some patients, the relatively low therapeutic efficacy precluded further studies with this combination of drugs.

Treatment patterns and outcomes for patients with adrenocortical carcinoma associated with hospital case volume in the United States

BACKGROUND

Adrenocortical carcinoma (ACC) is a rare, aggressive disease with no apparent change in treatment or survival in the United States over the past two decades. Our objective was to determine whether treatment patterns or clinical outcomes vary by hospital case volume.

METHODS

Patients with ACC were identified from the National Cancer Database (1998-2011). High-volume centers (HVCs) were defined by a case load of ≥4 cases of primary adrenal malignancy annually, which corresponded to the 90th percentile. All other facilities were considered low-volume centers (LVCs).

RESULTS

A total of 2,765 ACC patients were treated across 1,046 facilities. Compared to patients treated at LVCs, patients treated at HVCs were younger (50 vs. 54 years), with larger tumors (11.2 vs. 10.5 cm), and underwent higher rates of surgery (78.8 vs. 73.4 %), radical resection (17.3 vs. 13.9 %), regional lymph node evaluation (23.2 vs. 18.8 %), and chemotherapy including mitotane (43.8 vs. 31.0 %, all p < 0.05).There were no significant differences in median length of stay (5 vs. 5 days), 30-day readmission rates (4.0 % for HVCs vs. 3.9 % for LVCs), or 30-day postoperative mortality rates (1.9 % for HVCs vs. 3.7 % for LVCs). Median overall survival was 2.0 years for HVCs and 1.9 years for LVCs, p = 0.53. After adjusting for patient and tumor characteristics, overall survival did not differ significantly between patients treated at HVCs versus LVCs [HR = 0.89 (95 % confidence interval 0.70, 1.12)].

CONCLUSIONS

Treatment at HVCs was associated with more aggressive surgical resection and chemotherapy use. Prognosis remained poor despite more aggressive treatment.

EJE prize 2014: current and evolving treatment options in adrenocortical carcinoma: where do we stand and where do we want to go?

Adrenocortical carcinoma (ACC) is not only a rare and heterogeneous disease but also one of the most aggressive endocrine tumors. Despite significant advances in the last decade, its pathogenesis is still only incompletely understood and overall therapeutic means are unsatisfactory. Herein, we provide our personal view of the currently available treatment options and suggest the following research efforts that we consider timely and necessary to improve therapy: i) for better outcome in localized ACCs, surgery should be restricted to experienced centers, which should then collaborate closely to address the key surgical questions (e.g. best approach and extent of surgery) in a multicenter manner. ii) For the development of better systemic therapies, it is crucial to elucidate the exact molecular mechanisms of action of mitotane. iii) A prospective trial is needed to address the role of cytotoxic drugs in the adjuvant setting in aggressive ACCs (e.g. mitotane vs mitotane+cisplatin). iv) For metastatic ACCs, new regimens should be investigated as first-line therapy. v) Several other issues (e.g. the role of radiotherapy and salvage therapies) might be answered - at least in a first step - by large retrospective multicenter studies. In conclusion, although it is unrealistic to expect that the majority of ACCs can be cured within the next decade, international collaborative efforts (including multiple translational and clinical studies) should allow significant improvement of clinical outcome of this disease. To this end, it might be reasonable to expand the European Network for the Study of Adrenal Tumors (ENSAT) to a truly worldwide international network - INSAT.

MicroRNA era: the importance for diagnosis and prognosis of adrenocortical tumors

MicroRNAs play an essential role in posttranscriptional regulation of gene expression. They are evolutionary conserved, small, noncoding, 19–22-nucleotide RNAs, whose abnormalities, such as up- or downregulated expression, have been associated with several neoplasms, including adrenocortical tumors. Expression levels of distinct microRNAs can distinguish benign from malignant adrenal tumors. This current review provides recent data on the miRNAs profile in benign and malignant adrenocortical tumors diagnosed in adult and pediatric patients.

Adrenocortical carcinoma: the management of metastatic disease

Adrenocortical cancer is a rare malignancy. While surgery is the cornerstone of the management of localized disease, metastatic disease is hard to treat. Cytotoxic chemotherapy and mitotane have been utilized with a variable degree of benefit and few long-term responses. A growing understanding of the molecular pathogenesis of this malignancy as well as multidisciplinary and multi-institutional collaborative efforts will result in better defined targets and subsequently, effective novel therapies.

Videoscopic adrenalectomy - when does retroperitoneal seem better?

INTRODUCTION

Videoscopic adrenalectomy is the gold standard for the surgical treatment of benign adrenal tumours. The two most common approaches are the lateral transperitoneal approach (LTA) and the posterior retroperitoneal approach (PRA). So far it has not been established which is the preferable one. The choice depends primarily on the surgeon's preference and contraindications for a particular approach in individual cases.

AIM

To compare the two most common approaches for videoscopic adrenalectomy, LTA and PRA, based on a literature review and our own experience.

MATERIAL AND METHODS

We reviewed the literature (PubMed and Cochrane 1990 - current) and analysed retrospectively our own patients who underwent videoscopic adrenalectomy between 2009 and 2013. The analysis covered patient features, tumour characteristics, reasons for qualification for each approach, operative time and postoperative complications.

RESULTS

Out of 71 videoscopic adrenalectomies, 50 were performed using PRA and 21 using LTA. Patients in the PRA group on average were older, but had smaller tumours. There was no significant difference in perioperative morbidity between PRA and LTA. Mean blood loss and total operative time were smaller/shorter for the PRA group in comparison to the LTA group. Time to first oral intake and the average postoperative hospital stay were shorter for PRA than LTA.

CONCLUSIONS

Videoscopic adrenalectomy is a safe and efficient technique performed using both LTA and PRA approaches. The choice of technique should be guided, most of all, by surgeon experience, patient characteristics, tumour size and location. Our preferable approach is PRA, especially for small (< 6 cm) benign tumours. We find LTA advantageous for tumours of larger size, with suspected malignant character (either primary or secondary), in ectopic position, as well as in patients lacking an ipsilateral kidney or when a simultaneous abdominal operation is planned.

Adrenocortical carcinoma: what the surgeon needs to know. Case report and literature review

Adrenocortical carcinoma is a rare and aggressive cancer and its prognosis is frequently unsatisfactory. Due to its rarity there's a lack of prospective randomized studies. Without experience in the approach of this kind of tumor, managing becomes challenging and, moreover, we have only few recommendations, based on weak evidence. We report a case that has some peculiarities and is an excellent food for thought. Then we deal with a literature review to highlight and summarize most significant aspects of epidemiology, clinic, diagnosis, therapy and prognosis in an exquisitely surgical point of view.

Integrated genomic characterization of adrenocortical carcinoma

Adrenocortical carcinomas (ACCs) are aggressive cancers originating in the cortex of the adrenal gland. Despite overall poor prognosis, ACC outcome is heterogeneous. We performed exome sequencing and SNP array analysis of 45 ACCs and identified recurrent alterations in known driver genes (CTNNB1, TP53, CDKN2A, RB1 and MEN1) and in genes not previously reported in ACC (ZNRF3, DAXX, TERT and MED12), which we validated in an independent cohort of 77 ACCs. ZNRF3, encoding a cell surface E3 ubiquitin ligase, was the most frequently altered gene (21%) and is a potential new tumor suppressor gene related to the β-catenin pathway. Our integrated genomic analyses further identified two distinct molecular subgroups with opposite outcome. The C1A group of ACCs with poor outcome displayed numerous mutations and DNA methylation alterations, whereas the C1B group of ACCs with good prognosis displayed specific deregulation of two microRNA clusters. Thus, aggressive and indolent ACCs correspond to two distinct molecular entities driven by different oncogenic alterations.

Adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy, often with an unfavorable prognosis. Here we summarize the knowledge about diagnosis, epidemiology, pathophysiology, and therapy of ACC. Over recent years, multidisciplinary clinics have formed and the first international treatment trials have been conducted. This review focuses on evidence gained from recent basic science and clinical research and provides perspectives from the experience of a large multidisciplinary clinic dedicated to the care of patients with ACC.

The VEGF inhibitor axitinib has limited effectiveness as a therapy for adrenocortical cancer

CONTEXT

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis in need of more effective treatment options. Published evidence indicates many ACCs express the vascular endothelial growth factor receptor (VEGFR), suggesting inhibiting vascular endothelial growth factor signaling could potentially impact tumor growth.

OBJECTIVE

The objective of the study was to determine the antitumor efficacy of axitinib (AG-013736), a potent, selective inhibitor of VEGFR1, -2, and -3.

DESIGN

This was a phase II, open-label trial using a two-stage design.

PATIENTS

Thirteen patients with metastatic ACC previously treated with at least one chemotherapy regimen with or without mitotane participated in the study.

INTERVENTION

Starting axitinib dose was 5 mg orally twice daily. Dose escalations were permitted if the administered dose was tolerable.

RESULTS

Thirteen patients were enrolled. Dose escalation was possible in seven patients, but the majority could not tolerate a dose higher than the starting 5 mg, twice-daily dose for prolonged periods of time. All patients experienced known grade 1/2 toxicities, and 10 of 13 patients had at least one grade 3/4 adverse event. No patient tumor could be scored as a Response Evaluation Criteria in Solid Tumors response, although the growth rate on therapy compared with that prior to starting axitinib was reduced in 4 of the 13 patients. The median progression-free survival was 5.48 months, and the median overall survival was longer than 13.7 months.

CONCLUSION

Axitinib has limited effectiveness in ACC. Together with 48 patients previously reported who received either sorafenib or sunitinib, a total of 61 ACC patients have now been treated with a VEGFR tyrosine kinase inhibitor without an objective Response Evaluation Criteria in Solid Tumors response. Future trials in ACC should look to other targets for possible active agents.

Adrenal cortical carcinoma with extension into the inferior vena cava--case report and literature review

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy with an incidence rate of 1 to 2 per million person-years. ACC most commonly arises sporadically, but may be associated with familial tumour syndromes. Clinical symptoms are mainly related to an excess of steroid hormones. We present an unusual case of adrenocortical carcinoma in a 27-year-old male who complained of non specific mass-effect related symptoms of slowly growing intensity differing from others described in literature because of the patient’s age and the sudden deterioration of the clinical course. The tumour was resected with the left kidney with an extension into the inferior vena cava. Histological examination revealed morphological features characteristic of an adrenal cortical tumour. The immunohistochemical results (positive reactions for vimentin, CD56, inhibin, melan A, synaptophysin, bcl-2, calretinin) confirmed the diagnosis. According to the most widely used modified Weiss criteria and the Van Slooten system, a diagnosis of adrenal cortical carcinoma was strongly confirmed. The postoperative condition was poor. Reoperation was conducted, including abdominal aorta thrombectomy and aortic prosthesis implantation. The patient died two days after the second operation. Autopsy revealed a metastatic tumour in the left lung and morphological symptoms of acute circulatory collapse due to a massive haemorrhage into the abdominal cavity, which was the direct cause of death.

Management of adrenal cancer: a 2013 update

Adrenocortical carcinoma (ACC) is a devastating tumor for either patients or their families because of short life expectancy and severe impact on quality of life. Due to the rarity of ACC, with a reported annual incidence of 0.5-2 cases per million population, progress in the development of treatment options beyond surgery has been limited. Up to now, no personalized approach of ACC therapy has emerged, apart from plasma level-guided mitotane therapy, and no simple targetable molecular event has been identified from preclinical studies. Complete surgical removal of ACC is the only potentially curative approach and has the most important impact on patient’s prognosis. Despite the limits of the available evidence, adjuvant mitotane therapy is currently recommended in many expert centers whenever the patients present an elevated risk of recurrence. The management of patients with recurrent and metastatic disease is challenging and the prognosis is often poor. Mitotane monotherapy is indicated in the management of patients with a low tumor burden and/or more indolent disease while patients whose disease show an aggressive behavior need cytotoxic chemotherapy. The treatment of patients with advanced ACC may include loco-regional approaches such as surgery and radiofrequency ablation in addition to systemic therapies. The present review provides an updated overview of the management of ACC patients following surgery and of the management of ACC patients with advanced disease.

Molecular markers and targeted therapies for adrenocortical carcinoma

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

Operative intervention for recurrent adrenocortical cancer

INTRODUCTION

Adrenocortical cancer (ACC) recurs despite apparent complete resection. We examined the survival and palliative benefit of resection for recurrent ACC.

METHODS

A review of all patients undergoing operation for ACC between 1980 and 2010 at our institution was performed in which we compared resection with nonoperative therapy.

RESULTS

Overall, 164 patients underwent operation for ACC, 125 of whom underwent a complete resection (R0). Recurrence occurred in 93 R0 patients (median, 15 months; range, 1.5-150 months). Symptoms at recurrence were present in 71% (66/93), including pain (34%) and hormone excess (43%). There were 67 patients who underwent reoperation for recurrence. Forty-eight of 67 patients underwent R0 resection for recurrence. Operative patients had a greater overall operative versus nonoperative management or no therapy (65 months vs 6 months, P < .01). Median survival for nonoperatively managed patients (226 days) and those undergoing no therapy (179 days) was less than for debulking (1,272 days, P = .002). R0 for recurrence (P = .005) and a disease-free interval >6 months (P < .001) were associated with survival after operation, whereas original tumor size (P = .47), grade (P = .8), and stage (P = .23) were not. Pain and hormonal symptoms improved in 84% of operative patients versus 29% of nonoperatively managed patients (P = .005). Debulking had similar symptomatic improvement to R0 resection (P = .52).

CONCLUSION

Patients with recurrent ACC can benefit from operative intervention with improvement in survival and symptoms. Patients with a disease-free interval >6 months and complete resection are likely to benefit from resection of the recurrence, but the near universal improvement in symptoms may expand the criteria for operation in recurrent ACC.

MiR-34a and miR-483-5p are candidate serum biomarkers for adrenocortical tumors

BACKGROUND

Nonfunctioning adrenal incidentalomas are common and many patients undergo adrenalectomy to exclude adrenocortical carcinoma (ACC). Recent studies have shown dysregulated microRNA (miRNA) expression in ACC. The objective of this study was to determine the feasibility and diagnostic accuracy of measuring serum miRNAs in patients with benign and malignant adrenocortical neoplasms.

METHOD

Five miRNAs were selected from miRNA profiling studies in ACC (miR-let-7d, -34a, -195, -214, and 483-5p). Total miRNA was extracted from serum samples in patients with malignant and benign adrenal neoplasms. miRNAs levels were measured by quantitative reverse transcript polymerase chain reaction and normalized to miR-16. To determine if miRNAs were secreted from ACC cells, we measured miRNA levels in culture.

RESULTS

Serum samples from 22 patients with cortical adenomas and 17 patients with ACC were analyzed, and all 5 miRNAs were detected. We found greater levels of miR-34a (P = .001) and miR-483-5p (P = .011) in patients with ACC. The area under the receiver operating characteristic curve was 0.81 for miR-34a and 0.74 for miR-438-5p. MiR-34a and miR-483-5p levels in ACC cells were greater in the supernatant at 48 hours compared with intracellular levels.

CONCLUSION

We show that dysregulated miRNAs in ACC are detectable in human serum samples. MiR-34a and miR-483-5p are candidate serum biomarkers for distinguishing between benign and malignant adrenocortical tumors.

Adrenocortical carcinoma: clinical outcomes and prognosis of 330 patients at a tertiary care center

OBJECTIVE

Adrenocortical carcinoma (ACC) is a rare malignancy with a poor prognosis. Herein, we describe the clinical features and outcomes for a large series of ACC patients.

DESIGN AND METHODS

Retrospective review of ACC patients seen at The University of Texas MD Anderson Cancer Center from 1998 through 2011.

RESULTS

A total of 330 patients with median age at diagnosis of 48.5 years; 12 (3.6%) patients were under 18 years. Hormonally functioning tumors represented 41.8% (n=138) of all cases. Surgical resection for the primary tumor was done in 275 (83.3%) patients (45 at MD Anderson (16.4%)). For those who had surgical resection, the median local-recurrence-free time was 1.04 years. Factors associated with local recurrence included positive surgical margins (P=0.007) and advanced disease stage (P=0.026). Median overall survival time for all patients was 3.21 years. Median survival times were 24.1, 6.08, 3.47, and 0.89 years for stages I, II, III, and IV respectively. In multivariable analysis, older age, functioning tumors, and higher disease stage remained significant prognostic factors associated with poor survival.

CONCLUSION

ACC prognosis remains poor with the use of currently available treatments. Older age, functioning tumors, and incomplete resections are clinical factors associated with poor survival. Surgical expertise is important to achieve complete resections and to improve outcome.

Distinguishing adrenal cortical carcinomas and adenomas: a study of clinicopathological features and biomarkers

Aims

To determine clinicopathological criteria and molecular markers helpful in distinguishing adrenocortical carcinomas (ACCs) from adrenocortical adenomas (ACAs).

Methods and results

We analysed retrospectively the clinical and pathological features of 50 adrenal cortical tumours, and tested the expression of miR483-3p by in-situ hybridization as well as the expression of IGF2 and Smad4 by immunohistochemistry. We found that tumour size, tumour weight, hormonal function and the Weiss system are all high-efficacy criteria for differentiating malignant from benign tumours (P < 0.001). MiR483-3p was overexpressed in 68% (17 of 25) of ACCs compared to 12% (three of 25) of ACAs (P < 0.05). Using a combination of miR483-3p and Smad4 improved diagnostic accuracy. Molecular markers were then tested in an independent set of 15 borderline tumours. We confirmed that the combined use of miR483-3p and Smad4 immunochemistry can complement the Weiss score in the diagnosis of ACC in cases that display borderline histology.

Conclusions

Tumour size, tumour weight, hormonal function and the Weiss system are useful clinicopathological criteria that can result in accurate diagnosis of most ACCs and ACAs. In challenging cases, miR483-3p and Smad4 expression may help in distinguishing these two entities.

Non-functioning adrenocortical carcinoma arising in an adrenal rest: immunohistochemical study of an adult patient

Adrenal rest is uncommon in adults, and usually represents a small lesion incidentally detected during surgery or autopsy. The adrenal rest can be detected anywhere along the path of embryonic migration of adrenal cortex, including celiac axis, genitals and broad ligament, and may be formed with the separation of cortical fragments by the migration of medullary elements from the sympathochromaffin tissue into the preformed cortical primordium. In addition, even primary adrenocortical carcinoma is a rare tumor with incidence 0.5-2 per million annually; therefore, adrenocortical carcinoma arising in adrenal rests is extremely rare. We encountered a patient with non-functioning ectopic adrenocortical carcinoma in retroperitoneum. A 34-year-old female presented with an incidentally discovered retroperitoneal mass revealed by abdominal ultrasound in her regular health examinations. She did not have any clinical abnormalities and underwent hand-assisted laparoscopic resection of the tumor. A dark-brown tumor, measuring 65 × 56 × 45 mm, was identified in the retroperitoneal space between lower pole of right kidney and inferior vena cava. Histologically, the tumor was predominantly composed of compact eosinophilic cells forming nest-like arrangements and diffusely positive for the steroidogenic factor-1. The tumor met four of the criteria of Weiss used in histological diagnosis of adrenocortical carcinoma (eosinophillic cytoplasm, nuclear atypia, atypical mitosis, and sinusoidal invasion). The tumor cells were immunohistochemically positive for 17α-hydroxylase, dehydroepiandrosterone sulfotransferase and 3β-hydroxysteroid dehydrogenase, each of which is involved in the synthesis of adrenocortical steroids. Therefore, based on these findings, we diagnosed this tumor as ectopic adrenocortical carcinoma arising in adrenal rest of retroperitoneum.

Long-term survival after adrenalectomy for stage I/II adrenocortical carcinoma (ACC): a retrospective comparative cohort study of laparoscopic versus open approach

BACKGROUND

Laparoscopic adrenalectomy (LA) is the standard treatment for benign adrenal lesions. The laparoscopic approach has also been increasingly accepted for adrenal metastases but remains controversial for adrenocortical carcinoma (ACC). In a retrospective cohort study we compared the outcome of LA versus open adrenalectomy (OA) in the treatment of stage I and II ACC.

METHODS

This was a double cohort study comparing the outcome of patients with stage I/II ACC and a tumor size <10 cm submitted to LA or OA at Lille University Hospital referral center from 1985 to 2011. Main outcomes analyzed were: postoperative morbidity, overall survival, and disease-free survival.

RESULTS

Among 111 consecutive patients operated on for ACC, 34 met the inclusion criteria. LA and OA were performed in 13 and 21 patients, respectively. Baseline patient characteristics (gender, age, tumor size, hormonal secretion) were similar between groups. There was no difference in postoperative morbidity, but patients in LA group were discharged earlier (p < 0.02). After a similar follow-up (66 ± 52 for LA and 51 ± 43 months for OA), Kaplan-Meier estimates of disease-specific survival and disease-free survival were identical in both groups (p = 0.65, p = 0.96, respectively).

CONCLUSIONS

LA was associated with a shorter length of stay and did not compromise the long-term oncological outcome of patients operated on for stage I/II ACC ≤ 10 cm ACC. Our results suggest that LA can be safely proposed to patients with potentially malignant adrenal lesions smaller than 10 cm and without evidence of extra-adrenal extension.

Single nucleotide polymorphism array profiling of adrenocortical tumors--evidence for an adenoma carcinoma sequence?

Adrenocortical tumors consist of benign adenomas and highly malignant carcinomas with a still incompletely understood pathogenesis. A total of 46 adrenocortical tumors (24 adenomas and 22 carcinomas) were investigated aiming to identify novel genes involved in adrenocortical tumorigenesis. High-resolution single nucleotide polymorphism arrays (Affymetrix) were used to detect copy number alterations (CNAs) and copy neutral losses of heterozygosity (cnLOH). Genomic clustering showed good separation between adenomas and carcinomas, with best partition including only chromosome 5, which was highly amplified in 17/22 malignant tumors. The malignant tumors had more relevant genomic aberrations than benign tumors, such as a higher median number of recurrent CNA (2631 vs 94), CNAs >100 Kb (62.5 vs 7) and CN losses (72.5 vs 5.5), and a higher percentage of samples with cnLOH (91% vs 29%). Within the carcinoma cohort, a precise genetic pattern (i.e. large gains at chr 5, 7, 12, and 19, and losses at chr 1, 2, 13, 17, and 22) was associated with a better prognosis (overall survival: 72.2 vs 35.4 months, P=0.063). Interestingly, >70% of gains frequent in beningn were also present in malignant tumors. Notch signaling was the most frequently involved pathway in both tumor entities. Finally, a CN gain at imprinted “IGF2” locus chr 11p15.5 appeared to be an early alteration in a multi-step tumor progression, followed by the loss of one or two alleles, associated with increased IGF2 expression, only in carcinomas. Our study serves as database for the identification of genes and pathways, such as Notch signaling, which could be involved in the pathogenesis of adrenocortical tumors. Using these data, we postulate an adenoma-carcinoma sequence for these tumors.

Mitotane levels predict the outcome of patients with adrenocortical carcinoma treated adjuvantly following radical resection

CONTEXT

Mitotane plasma concentrations ≥ 14 mg/l have been shown to predict tumor response and better survival in patients with advanced adrenocortical carcinoma (ACC). A correlation between mitotane concentrations and patient outcome has not been demonstrated in an adjuvant setting.

OBJECTIVE

To compare recurrence-free survival (RFS) in patients who reached and maintained mitotane concentrations ≥ 1 4 mg/l vs patients who did not.

DESIGN AND SETTING

Retrospective analysis at six referral European centers.

PATIENTS

Patients with ACC who were radically resected between 1995 and 2009 and were treated adjuvantly with mitotane targeting concentrations of 14-20 mg/l.

MAIN OUTCOME MEASURES

RFS (primary) and overall survival (secondary).

RESULTS

Of the 122 patients included, 63 patients (52%) reached and maintained during a median follow-up of 36 months the target mitotane concentrations (group 1) and 59 patients (48%) did not (group 2). ACC recurrence was observed in 22 patients of group 1 (35%) and 36 patients in group 2 (61%). In multivariable analysis, the maintenance of target mitotane concentrations was associated with a significantly prolonged RFS (hazard ratio (HR) of recurrence: 0.418, 0.22-0.79; P=0.007), while the risk of death was not significantly altered (HR: 0.59, 0.26-1.34; P=0.20). Grades 3-4 toxicity was observed in 11 patients (9%) and was managed with temporary mitotane discontinuation. None of the patients discontinued mitotane definitively for toxicity.

CONCLUSIONS

Mitotane concentrations ≥ 14 mg/l predict response to adjuvant treatment being associated with a prolonged RFS. A monitored adjuvant mitotane treatment may benefit patients after radical removal of ACC.

Giant adrenocortical carcinoma with 27-month disease-free survival by surgical resection alone: a case report

BACKGROUND

Adrenocortical cancer (ACC) is a rare disease with an estimated incidence of 1-2/million/year. The tumour stage and completeness of surgical resection have the biggest impact on survival. Whereas stage I-II patients survive in 55-64% of cases, only 0-5% of patients with stage IV disease are still alive at 5 years. A median survival of 33 months can be expected after curative surgery. Incomplete surgery leads to a significant drop in survival.

METHOD

We present a 40-year-old man who underwent a technically demanding complete surgical excision of a giant (26 cm, 2372 g) ACC and experienced a 27-month disease-free survival without any systemic treatment. Detailed description of the surgical anatomy in relation to tumour size and patient body constitution is provided. The surgical strategy and exposure pitfalls under such extreme circumstances are discussed.

CONCLUSION

To achieve R0 resection in locally advanced disease, en bloc resection with neighbouring organs is widely recommended. Giant tumours may however pose a technical challenge due to space constraints.

Current management options for recurrent adrenocortical carcinoma

Adrenal cortical carcinoma (ACC) is a rare cancer that poses a number of management challenges due to the limited number of effective systemic treatments. Complete surgical resection offers the best chance of long-term survival. However, despite complete resection, ACC is associated with high recurrence rates. This review will discuss the management of recurrent ACC in adults following complete surgical resection. Management should take place in a specialist center and treatment decisions must consider the individual tumor biology of each case of recurrence. Given the fact that ACC commonly recurs, management to prevent recurrence should be considered from initial diagnosis with the use of adjuvant mitotane. Close follow up with clinical examination and imaging is important for early detection of recurrent disease. Locoregional recurrence may be isolated, and repeat surgical resection should be considered along with mitotane. The use of radiotherapy in ACC remains controversial. Systemic recurrence most often involves liver, pulmonary, and bone metastasis and is usually managed with mitotane, with or without combination chemotherapy. There is a limited role for surgical resection in systemic recurrence in selected patients. In all patients with recurrent disease, control of excessive hormone production is an important part of management. Despite intensive management of recurrent ACC, treatment failure is common and the use of clinical trials and novel treatment is an important part of management.

Mitotane alters mitochondrial respiratory chain activity by inducing cytochrome c oxidase defect in human adrenocortical cells

Mitotane, 1,1-dichloro-2-(o-chlorophenyl)-2-(p-chlorophenyl)ethane is the most effective medical therapy for adrenocortical carcinoma, but its molecular mechanism of action remains poorly understood. Although mitotane is known to have mitochondrial (mt) effects, a direct link to mt dysfunction has never been established. We examined the functional consequences of mitotane exposure on proliferation, steroidogenesis, and mt respiratory chain, biogenesis and morphology, in two human adrenocortical cell lines, the steroid-secreting H295R line and the non-secreting SW13 line. Mitotane inhibited cell proliferation in a dose- and a time-dependent manner. At the concentration of 50 μM (14 mg/l), which corresponds to the threshold for therapeutic efficacy, mitotane drastically reduced cortisol and 17-hydroxyprogesterone secretions by 70%. This was accompanied by significant decreases in the expression of genes encoding mt proteins involved in steroidogenesis (STAR, CYP11B1, and CYP11B2). In both H295R and SW13 cells, 50 μM mitotane significantly inhibited (50%) the maximum velocity of the activity of the respiratory chain complex IV (cytochrome c oxidase (COX)). This effect was associated with a drastic reduction in steady-state levels of the whole COX complex as revealed by blue native PAGE and reduced mRNA expression of both mtDNA-encoded COX2 (MT-CO2) and nuclear DNA-encoded COX4 (COX4I1) subunits. In contrast, the activity and expression of respiratory chain complexes II and III were unaffected by mitotane treatment. Lastly, mitotane exposure enhanced mt biogenesis (increase in mtDNA content and PGC1α (PPARGC1A) expression) and triggered fragmentation of the mt network. Altogether, our results provide first evidence that mitotane induced a mt respiratory chain defect in human adrenocortical cells.