Etoposide, doxorubicin and cisplatin plus mitotane in the treatment of advanced adrenocortical carcinoma: a large prospective phase II trial

Adjuvant therapies and patient and tumor characteristics associated with survival of adult patients with adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma is a rare malignant endocrine neoplasia. Studies regarding outcome and prognostic factors rely on fairly small studies. Here we summarize the experience with patients with a diagnosis of adrenocortical carcinoma from a large tertiary referral center.

OBJECTIVE

The objective of the study was to identify prognostic factors in patients with adrenocortical carcinoma and evaluate adjuvant treatment strategies.

DESIGN

Patient data were collected in a retrospective single-center study. Epidemiological, patient, and tumor characteristics were analyzed for prognostic factors regarding overall and recurrence-free survival in Cox regression models (multivariable and univariable).

RESULTS

Three hundred ninety-one adult patients with the diagnosis of adrenocortical carcinoma were identified. Median overall survival was 35.2 months. Cortisol production [hazard ratio (HR) 1.4, HR 1.5], tumor stage (HR stage 3 of 2.1 and 2.1, HR stage 4 of 4.8), and tumor grade (HR 2.4 and 2.0) were identified as negative prognostic factors (HR for death, HR for recurrence). Mitotane therapy increases recurrence-free survival, an effect that was significantly further improved by adjuvant radiation therapy but did not impact overall survival. Patients with open adrenalectomy had improved overall survival.

CONCLUSIONS

This study increases the evidence for adverse risk factors (cortisol production, high tumor stage, and high tumor grade) and suggests the following therapy approach: adrenocortical carcinoma patients should be treated with open adrenalectomy. Adjuvant therapy, particularly mitotane therapy in conjunction with radiation, should be considered to delay tumor recurrence.

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.

Interferon-β is a potent inhibitor of cell growth and cortisol production in vitro and sensitizes human adrenocortical carcinoma cells to mitotane

Adrenocortical carcinoma (ACC) is an aggressive tumor with very poor prognosis. Novel medical treatment opportunities are required. We investigated the effects of interferon-β (IFN-β), alone or in combination with mitotane, on cell growth and cortisol secretion in primary cultures of 13 human ACCs, three adrenal hyperplasias, three adrenal adenomas, and in two ACC cell lines. Moreover, the interrelationship between the effects of IGF2 and IFN-β was evaluated. Mitotane inhibited cell total DNA content/well (representing cell number) in 7/11 (IC50: 38±9.2 μM) and cortisol secretion in 5/5 ACC cultures (IC50: 4.5±0.1 μM). IFN-β reduced cell number in 10/11 (IC50: 83±18 IU/ml) and cortisol secretion in 5/5 ACC cultures (IC50: 7.3±1.5 IU/ml). The effect of IFN-β on cell number included the induction of apoptosis. IFN-β strongly inhibited mRNA expression of STAR, CYP11A1, CYP17A1, and CYP11B1. Mitotane and IFN-β induced an additive inhibitory effect on cell number and cortisol secretion. IGF2 (10 nM) inhibited apoptosis and increased cell number and cortisol secretion. These effects were counteracted by IFN-β treatment. Finally, IFN-β inhibited IGF2 secretion and mRNA expression. In conclusion, IFN-β is a potent inhibitor of ACC cell growth in human primary ACC cultures, partially mediated by an inhibition of the effects of IGF2, as well as its production. The increased sensitivity of ACC cells to mitotane induced by treatment with IFN-β may open the opportunity for combined treatment regimens with lower mitotane doses. The inhibition of the expression of steroidogenic enzymes by IFN-β is a novel mechanism that may explain its inhibitory effect on cortisol production.

Recent advances in adrenocortical carcinoma in adults

PURPOSE OF REVIEW

Adrenocortical cancer (ACC) is a rare and often aggressive malignancy. The overall 5-year survival rate of ACC is less than 30% in part owing to advanced stage of the disease at diagnosis and limited efficiency of therapies when initial surgery is not curative. So far, studies with large cohorts of patients affected by ACC were lacking because of the rarity of the disease; however, recent international and multicenter collaborative studies provide new insights in the management of ACC.

RECENT FINDINGS

This review summarizes recent findings in the genetic, hormonal evaluation, imaging, and therapies of ACC in adults. There is new promise for the use of 2-[fluorine-18]fluoro-2-deoxy-D-glucose-positron emission tomography and metomidate in initial diagnosis and follow-up. Limited studies support benefit of specific surgical approaches such as loco-regional lymph node dissection and metastasectomy in specific subgroups. New developments in the use of mitotane therapy and its drug interactions, on adjuvant radiotherapy and prospective data on combined chemotherapy, have appeared recently.

SUMMARY

These recent findings will provide more evidence-based recommendations in the future to better assist clinicians in the management of patients with ACC. However, there is still an important need to understand the molecular mechanisms underlying this disease to design better therapeutic approaches.

TOP2A is overexpressed and is a therapeutic target for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy with no effective therapy for patients with unresectable disease. The aim of the current study was i) to evaluate TOP2A expression and function in human adrenocortical neoplasm and ACC cells and ii) to determine the anticancer activity of agents that target TOP2A. TOP2A mRNA and protein expression levels were evaluated in 112 adrenocortical tissue samples (21 normal adrenal cortex, 80 benign adrenocortical tumors, and 11 ACCs). In vitro siRNA knockdown of TOP2A in ACC cell lines (NCI-H295R and SW13) was used to determine its effect on cellular proliferation, cell cycle, anchorage-independent growth, and cellular invasion. We screened 14 TOP2A inhibitors for their anticancer activity in ACC cells. TOP2A mRNA and protein expression was significantly higher in ACC than in benign and normal adrenocortical tissue samples (P<0.05). Knockdown of TOP2A gene expression in ACC cell lines significantly decreased cell proliferation, anchorage-independent growth, and invasion (P<0.05). A screening assay in NCI-H295R cells showed that 11 of 14 TOP2A inhibitors had antiproliferative activity, 5 of the 14 TOP2A inhibitors had a higher antiproliferative activity than mitotane, and aclarubicin was the agent with the highest activity. Aclarubicin was validated to significantly decrease proliferation and tumor spheroid size in both NCI-H295R and SW13 ACC cell lines (P<0.05). Our results suggest that TOP2A is overexpressed in ACC, regulates cellular proliferation and invasion in ACC cells, and is an attractive target for ACC therapy. Of the TOP2A inhibitors screened, aclarubicin is a good candidate agent to test in future clinical trials for patients with locally advanced and metastatic ACC.

Treatment with docetaxel and cisplatin in advanced adrenocortical carcinoma, a phase II study

Background:

Adrenocortical carcinoma (ACC) is a rare disease with a poor response to chemotherapy. Cisplatin is the most widely investigated drug in the treatment of ACC and in vitro studies have indicated activity of taxanes. The objectives of this study were to evaluate the efficacy and toxicity of cisplatin combined with docetaxel as first-line treatment of advanced ACC.

Methods:

Patients with advanced ACC were included in this phase II trial investigating the response to a combination of cisplatin (50 mg m⁻²) and docetaxel (60 mg m⁻²) administered with a 3-week interval.

Results:

Nineteen patients were included in this study. The response rate was 21% (95% CI: 3–39%). No patients obtained a complete response, 32% had stable disease, and 37% progressed while on treatment. The median progression-free survival (PFS) was 3 months (95% CI: 0.7–5.3 months) and 1 year PFS was 21% (95% CI: 3–39%). Median survival was 12.5 months (95% CI: 6–19 months). The predominant grade 3/4 toxicity was neutropenia (35%); febrile neutropenia occurred in 5% of cycles.

Conclusion:

This study could not demonstrate that the combination of cisplatin and docetaxel has higher efficacy than other regimens reported in previous studies.

Metronomic chemotherapy may be active in heavily pre-treated patients with metastatic adreno-cortical carcinoma

OBJECTIVE

The potential benefit of further chemotherapy approaches in patients with adrenocortical carcinoma (ACC) showing progressive disease after 2 chemotherapy lines is actually unknown. This study provides explorative information on the activity of metronomic chemotherapy in heavily pre-treated ACC patients.

DESIGN AND METHODS

We tested the activity of cytotoxic treatments administered on a metronomic schedule in metastatic ACC patients showing disease progression after treatment with gemcitabine and capecitabine scheme.

RESULTS

Eight patients out of 28 consecutively enrolled in that trial were treated with several metronomic cytotoxic regimens. Six of them showed disease progression, but 2 patients obtained a clear benefit. The first patient was treated with oral etoposide (50 mg daily) as the 6th-line therapy and obtained a partial response lasting 24 months, while the second patient obtained a partial response lasting 10 months with metronomic oral cyclophosphamide (50 mg daily) as the 5th chemotherapy line. Both patients had sex hormone secreting tumors and were bearing a rather indolent ACC.

CONCLUSIONS

The administration of several chemotherapy lines in advanced ACC patients cannot be routinely recommended outside prospective clinical trials. Few patients with indolent tumors, however, may benefit from this approach. According to our experience, oral cyclophosphamide and oral etoposide may be used in this setting.

Establishment and characterization of the first pediatric adrenocortical carcinoma xenograft model identifies topotecan as a potential chemotherapeutic agent

PURPOSE

Pediatric adrenocortical carcinoma (ACC) is a rare and highly aggressive malignancy. Conventional chemotherapeutic agents have shown limited utility and are largely ineffective in treating children with advanced ACC. The lack of cell lines and animal models of pediatric ACC has hampered the development of new therapies. Here we report the establishment of the first pediatric ACC xenograft model and the characterization of its sensitivity to selected chemotherapeutic agents.

EXPERIMENTAL DESIGN

A tumor from an 11-year-old boy with previously untreated ACC was established as a subcutaneous xenograft in immunocompromised CB17 scid(-/-) mice. The patient harbored a germline TP53 G245C mutation, and the primary tumor showed loss of heterozygosity with retention of the mutated TP53 allele. Histopathology, DNA fingerprinting, gene expression profiling, and biochemical analyses of the xenograft were conducted and compared with the primary tumor and normal adrenal cortex. The second endpoint was to assess the preliminary antitumor activity of selected chemotherapeutic agents.

RESULTS

The xenograft maintained the histopathologic and molecular features of the primary tumor. Screening the xenograft for drug responsiveness showed that cisplatin had a potent antitumor effect. However, etoposide, doxorubicin, and a panel of other common cancer drugs had little or no antitumor activity, with the exception of topotecan, which was found to significantly inhibit tumor growth. Consistent with these preclinical findings, topotecan as a single agent in a child with relapsed ACC resulted in disease stabilization.

CONCLUSION

Our study established a novel TP53-associated pediatric ACC xenograft and identified topotecan as a potentially effective agent for treating children with this disease.

Adrenocortical Carcinoma: Current Therapeutic State-of-the-Art

Adrenocortical carcinoma (ACC) is a rare, aggressive malignancy that generally conveys a poor prognosis. Currently, surgical resection is considered the lone curative treatment modality. In addition, the low prevalence of ACC has limited effective clinical trial design to develop evidence-based approaches to ACC therapy. The proper role of radio- and chemotherapy treatment for ACC is still being defined. Similarly, the molecular pathogenesis of ACC remains to be fully characterized. Despite these challenges, progress has been made in several areas. After years of refinement, an internationally accepted staging system has been defined. International collaborations have facilitated increasingly robust clinical trials, especially regarding agent choice and patient selection for chemotherapeutics. Genetic array data and molecular profiling have identified new potential targets for rational drug design as well as potential tumor markers and predictors of therapeutic response. However, these advances have not yet been translated into a large outcomes benefit for ACC patients. In this paper, we summarize established therapy for ACC and highlight recent findings in the field that are impacting clinical practice.

Analysis of the role of Igf2 in adrenal tumour development in transgenic mouse models

Adrenal cortical carcinomas (ACC) are rare but aggressive tumours associated with poor prognosis. The two most frequent alterations in ACC in patients are overexpression of the growth factor IGF2 and constitutive activation of Wnt/β-catenin signalling. Using a transgenic mouse model, we have previously shown that constitutive active β-catenin is a bona fide adrenal oncogene. However, although all these mice developed benign adrenal hyperplasia, malignant progression was infrequent, suggesting that secondary genetic events were required for aggressive tumour development. In the present paper, we have tested IGF2 oncogenic properties by developing two distinct transgenic mouse models of Igf2 overexpression in the adrenal cortex. Our analysis shows that despite overexpression levels ranging from 7 (basal) to 87 (ACTH-induced) fold, Igf2 has no tumour initiating potential in the adrenal cortex. However, it induces aberrant accumulation of Gli1 and Pod1-positive progenitor cells, in a hedgehog-independent manner. We have also tested the hypothesis that Igf2 may cooperate with Wnt signalling by mating Igf2 overexpressing lines with mice that express constitutive active β-catenin in the adrenal cortex. We show that the combination of both alterations has no effect on tumour phenotype at stages when β-catenin-induced tumours are benign. However, there is a mild promoting effect at later stages, characterised by increased Weiss score and proliferation. Formation of malignant tumours is nonetheless a rare event, even when Igf2 expression is further increased by ACTH treatment. Altogether these experiments suggest that the growth factor IGF2 is a mild contributor to malignant adrenocortical tumourigenesis.

Current and emerging therapeutic options in adrenocortical cancer treatment

Adrenocortical carcinoma (ACC) is a very rare endocrine tumour, with variable prognosis, depending on tumour stage and time of diagnosis. The overall survival is five years from detection. Radical surgery is considered the therapy of choice in the first stages of ACC. However postoperative disease-free survival at 5 years is only around 30% and recurrence rates are frequent. o,p'DDD (ortho-, para'-, dichloro-, diphenyl-, dichloroethane, or mitotane), an adrenolytic drug with significant toxicity and unpredictable therapeutic response, is used in the treatment of ACC. Unfortunately, treatment for this aggressive cancer is still ineffective. Over the past years, the growing interest in ACC has contributed to the development of therapeutic strategies in order to contrast the neoplastic spread. In this paper we discuss the most promising therapies which can be used in this endocrine neoplasia.

Adrenal cortical carcinoma with late pulmonary metastases causing clinicical Cushing's syndrome: case report with immunohistochemical analysis of steriodogenic enzyme production

OBJECTIVE

To present a case of pulmonary metastases from adrenocortical carcinomas (ACC) that were secreting fully-functional cortisol resulting in clinical Cushing's syndrome and to compare the steroidogenic enzyme expression in the primary tumor and lung.

METHODS

We analyzed and summarized the patient's medical history, physical examination results, laboratory data, imaging studies, and histopathologic results. The original tumor and the pulmonary metastases were then immunohistochemically evaluated for steroidogenic enzymes.

RESULTS

Initial endocrinological workup revealed hyperandrogenism and adrenocorticotropic hormone (ACTH) independent Cushing's due to a 4 cm left adrenal mass. The patient was initially diagnosed with an adrenal adenoma. Four years later, the patient developed recurrent Cushing's syndrome. Repeat magnetic resonance imaging (MRI) showed no adrenal masses; however, chest computed tomography (CT) showed multiple bilateral lung nodules and biopsy revealed metastases of adrenal origin. Upon immunohistochemical analysis, side chain cleavage, 17α hydroxylase, 3β hydroxysteroid dehydrogenase, and 21 hydroxylase immunoreactivity were detected in both the original and pulmonary metastatic lesions with patterns of disorganized steroidogenesis. Dehydroepiandrosterone-sulfotransferase (DHEA-ST) immunoreactivity was detected in the original tumor but not in the lung metastases.

CONCLUSION

This case demonstrates some interesting features of ACC that pose challenges to its management, including the difficulties in establishing the pathologic diagnosis, the potential for fully functional steroidogenesis even in late metastases, and the plasticity of steroidogenic potential in tumor cells.

The next generation of therapies for adrenocortical cancers

Adrenocortical carcinoma (ACC) is a rare cancer for which few treatment options have been available. Currently, the best available treatment involves combination chemotherapy with the adrenolytic drug mitotane, although the response rate remains modest. Over the past 10 years there has been renewed interest in the field owing to the recognition that targeted therapies may provide new avenues for effective treatment of this deadly disease. Molecular analyses have revealed specific signaling alterations in ACC, and advances in drug development have generated the tools to block these pathways. Although convincing evidence for the effectiveness of targeted therapies is not currently available, these studies are in progress and should shift the prognosis of this disease in the years to come.

Combination chemotherapy in advanced adrenocortical carcinoma

BACKGROUND

Adrenocortical carcinoma is a rare cancer that has a poor response to cytotoxic treatment.

METHODS

We randomly assigned 304 patients with advanced adrenocortical carcinoma to receive mitotane plus either a combination of etoposide (100 mg per square meter of body-surface area on days 2 to 4), doxorubicin (40 mg per square meter on day 1), and cisplatin (40 mg per square meter on days 3 and 4) (EDP) every 4 weeks or streptozocin (streptozotocin) (1 g on days 1 to 5 in cycle 1; 2 g on day 1 in subsequent cycles) every 3 weeks. Patients with disease progression received the alternative regimen as second-line therapy. The primary end point was overall survival.

RESULTS

For first-line therapy, patients in the EDP-mitotane group had a significantly higher response rate than those in the streptozocin-mitotane group (23.2% vs. 9.2%, P<0.001) and longer median progression-free survival (5.0 months vs. 2.1 months; hazard ratio, 0.55; 95% confidence interval [CI], 0.43 to 0.69; P<0.001); there was no significant between-group difference in overall survival (14.8 months and 12.0 months, respectively; hazard ratio, 0.79; 95% CI, 0.61 to 1.02; P=0.07). Among the 185 patients who received the alternative regimen as second-line therapy, the median duration of progression-free survival was 5.6 months in the EDP-mitotane group and 2.2 months in the streptozocin-mitotane group. Patients who did not receive the alternative second-line therapy had better overall survival with first-line EDP plus mitotane (17.1 month) than with streptozocin plus mitotane (4.7 months). Rates of serious adverse events did not differ significantly between treatments.

CONCLUSIONS

Rates of response and progression-free survival were significantly better with EDP plus mitotane than with streptozocin plus mitotane as first-line therapy, with similar rates of toxic events, although there was no significant difference in overall survival. (Funded by the Swedish Research Council and others; FIRM-ACT ClinicalTrials.gov number, NCT00094497.).

Ribonucleotide reductase large subunit (RRM1) gene expression may predict efficacy of adjuvant mitotane in adrenocortical cancer

PURPOSE

Mitotane is the most broadly used systemic therapy for adrenocortical carcinoma (ACC), but its mechanism of action and possible predictors of treatment response are currently poorly defined. Our aim was to evaluate the gene expression of ribonucleotide reductase large subunit 1 (RRM1) and excision repair cross-complementation group 1 (ERCC1) in ACC as potential biomarkers for clinical outcome and response to mitotane.

EXPERIMENTAL DESIGN

Forty-five and 47 tissue samples from two cohorts (Orbassano, Italy; Wuerzburg, Germany) of completely resected ACC were centrally analyzed using real-time PCR for RRM1 and ERCC1 expression. Fifty-four patients received surgery alone and 38 received adjuvant mitotane after surgery. Clinical and pathologic features were highly comparable in the two series. H295R and SW-13 ACC cell lines were also used for pharmacologic tests.

RESULTS

ERCC1 gene expression was not associated to clinical outcome. In contrast, high RRM1 gene expression was associated to shorter disease-free survival (DFS) and overall survival at both univariate and multivariate analysis. In patients with low RRM1 gene expression, adjuvant mitotane was associated with improved DFS, whereas this effect was lost in cases with high RMM1 expression. In vitro mitotane induced strong up regulation of RRM1 transcription (up to 25-fold increase) in mitotane-insensitive SW-13 but not in mitotane-sensitive H295R cells. Furthermore, RRM1 silencing in SW-13 cells induced sensitivity to mitotane.

CONCLUSION

Our in vitro and in vivo data indicate that RRM1 gene expression is functionally associated to mitotane sensitivity and support a possible role of RRM1 determination as a novel molecular biomarker predicting response to adjuvant mitotane in ACC.

Resection of adrenocortical carcinoma liver metastasis: is it justified?

BACKGROUND

Adrenocortical carcinoma (ACC) liver metastases (LM) represent a therapeutic challenge, and it is unclear whether resection is justified. This study assesses long-term outcome and prognostic factors after liver resection for metastatic ACC.

METHODS

Patients who underwent resection of ACC LM were identified from institutional databases. Recurrence, survival, and tumor characteristics, including β-catenin and TP53 status based on immunohistochemistry and sequencing, were reviewed. The prognostic value of variables was assessed with log-rank test for univariate analysis and Cox proportional hazard models for multivariate analysis.

RESULTS

From 1978 to 2009, 28 patients (20 females; median age, 45 years), including 11 with synchronous metastasis and 3 with extrahepatic metastasis, underwent resection for ACC LM (major hepatectomy in 61%). Postoperative mortality was nil and morbidity 55%. On pathological examination, tumors were multiple in 68%, with a median size of 43 mm, and resections were R0, 1, and 2 in 59%, 33%, and 7%, respectively. All 28 patients developed recurrent disease, which was treated surgically in 11, including repeat hepatectomy in 4. Of the 15 patients with adequate tissue for analysis, β-catenin immunostaining was positive in 7, with 4 corresponding CTNNB1 mutations associated with decreased survival; p53 staining was positive in 5 (4 with corresponding TP53 mutations). The median disease-free and overall survival after hepatectomy was 7 and 31.5 months, respectively, with a 5-year survival of 39%. In multivariate analysis, nonfunctional tumor and surgical treatment of recurrence were independent predictors of good outcome.

CONCLUSIONS

In selected patients with ACC LM, resection is associated with long-term survival and is, therefore, justified but rarely curative.

Targeted therapies for adrenocortical carcinoma: IGF and beyond

Standard chemotherapy for adrenocortical cancer currently is under evaluation in the context of the recently completed FIRM-ACT evaluating the combination of mitotane with either streptozocin or etoposide, cisplatin, and doxorubicin. New agents are eagerly sought by the ACC community that hopes to make progress against this deadly disease. Investigators have begun to dissect the molecular and genomic context of ACC with a goal of identifying potential novel therapeutic agents. One gene consistently overexpressed in ACC is insulin growth factor type 2. Targeting its receptor IGF1R has shown encouraging results in ACC cell lines and against murine xenografts. As a result, clinical trials to evaluate agents targeting the IGF1R have been done including mitotane and IMC-A12 (a monoclonal antibody) and the GALACCTIC trial that has just completed accrual to evaluate OSI-906, a small molecule IGF1R antagonist. On the horizon are other agents targeting other tyrosine kinases, including EGF and FGF, and novel strategies such as individualized tumor analysis to select treatment.

Adrenocortical carcinoma: past, present, and future

Adrenocortical carcinoma (ACC) is a rare endocrine malignancy. Due to its rarity, heterogeneity, and a lack of a comprehensive understanding of the pathogenesis, little progress has been made in treatment and outcomes. The current review explores the past, present, and future of the understanding and treatment of this disease process.

Xenograft models for preclinical drug testing: implications for adrenocortical cancer

Adrenocortical carcinoma (ACC) is a very rare but aggressive tumor, whose biological and cellular features and processes underlying the development, progression and metastatic evolution are still obscure. Despite many attempts to use general cytostatic and cytotoxic drugs, the only available drug therapy for advanced ACC is still represented by mitotane (MTT). However, the mechanism of action of this adrenolytic derivative of the pesticide DDT has still been poorly characterized. In this context, the development of more specific drugs for ACC treatment is based on the knowledge of the molecular pathways involved in the tumor growth. Xenograft models for the screening of such drugs at preclinical levels is mandatory. In the first part of this review, we will summarize the "pro" and "con" of the different xenograft models available for anticancer drug testing in different types of tumors in general and in the last part, we will focus on the preclinical evidence obtained so far with the use of such models applied to drug screening for anticancer effects in ACC.

Clinical and imaging overview of functional adrenal neoplasms

Adrenal adenoma, adrenocortical carcinoma, pheochromocytoma and neuroblastoma are four discrete adrenal neoplasms that have the potential for functional activity. Functional adrenal neoplasms can secrete cortisol, aldosterone, sex hormones or catecholamines. These heterogeneous groups of tumors show varied biological behavior and clinical outcomes. These neoplasms are encountered with increasing clinical frequency as a result of an expansion in the volume of medical imaging carried out. The clinical presentation, including prognosis and treatment options, and the imaging features of these neoplasms are discussed. The key radiological observations of each of these neoplasms are shown using multimodality images. Familiarity with the clinical and imaging features of these neoplasms improves diagnosis, and facilitates appropriate clinical decision-making and patient management.

[131I]iodometomidate for targeted radionuclide therapy of advanced adrenocortical carcinoma

CONTEXT

In advanced adrenocortical carcinoma (ACC), many patients have progressive disease despite standard treatment, indicating a need for new treatment options. We have shown high and specific retention of [123I]metomidate ([123I]IMTO) in ACC lesions, suggesting that labeling of metomidate with 131I offers targeted radionuclide therapy for advanced ACC.

OBJECTIVE

Safety and efficacy of radionuclide therapy with [131I]IMTO in advanced ACC.

DESIGN/SETTING

This monocentric case series comprised 19 treatments in 11 patients with nonresectable ACC.

PATIENTS AND INTERVENTION

Between 2007 and 2010, patients with advanced ACC not amenable to radical surgery and exhibiting high uptake of [123I]IMTO in their tumor lesions were offered treatment with [131I]IMTO (1.6-20 GBq in one to three cycles of [131I]IMTO).

MAIN OUTCOME MEASURE

Tumor response was assessed according to response evaluation criteria in solid tumors (RECIST version 1.1) criteria, and side effects were assessed by Common Toxicity Criteria (version 4.0).

RESULTS

Best response was classified as partial response in one case with a change in target lesions of -51% from baseline, as stable disease in five patients, and as progressive disease in four patients. One patient died 11 d after treatment with [131I]IMTO unrelated to radionuclide therapy. In patients responding to treatment, median progression-free survival was 14 months (range, 5-33) with ongoing disease stabilization in three patients at last follow-up. Treatment was well tolerated, but transient bone marrow depression was observed. Adrenal insufficiency developed in two patients.

CONCLUSIONS

Radionuclide therapy with [131I]IMTO is a promising treatment option for selected patients with ACC, deserving evaluation in prospective clinical trials.

Liver resection for liver metastases from nondigestive endocrine cancer: extrahepatic disease burden defines outcome

BACKGROUND

For patients with hepatic nondigestive endocrine metastases (HNEM), the role of liver resection is not well-defined.

METHODS

We reviewed outcomes for patients who underwent liver resection for HNEM at 2 centers to identify predictors of survival.

RESULTS

From 1991 to 2010, 51 patients underwent liver resection for HNEM. Primary tumor types were adrenal gland (n = 26), thyroid (n = 11), testicular germ cell (n = 9), and ovarian granulosa cell (n = 5). 28 patients (55%) had synchronous or early (diagnosed within 12 months after primary tumor resection) liver metastases. At liver resection, 26 patients (51%) had extrahepatic metastases, and 7 (14%) had ≥2 sites of extrahepatic metastases. 32 patients (63%) had major liver resection and 19 (37%) had a simultaneous extrahepatic procedure. 90-day postoperative morbidity and mortality rates were 27% and 2%, respectively. After median follow-up of 20 months (range, 1-144), the 5-year overall and recurrence-free survival rates were 58% and 37%, respectively. Survival was not affected by primary tumor type. In multivariate analysis, ≥2 sites of extrahepatic metastases (hazard ratio [HR] = 4.80; 95% confidence interval [CI] = 1.18-19.50; P = .028) and interval of ≤12 months between primary tumor resection and diagnosis of liver metastases (HR = 5.33; 95% CI = 1.11-25.71; P = .037) were associated with worse overall survival after liver resection.

CONCLUSION

For selected patients, liver resection for HNEM is associated with long-term survival. The number of extrahepatic sites of metastasis and the timing of appearance of liver metastases should be considered in patient selection.

High-dose mitotane strategy in adrenocortical carcinoma: prospective analysis of plasma mitotane measurement during the first 3 months of follow-up

BACKGROUND

The benefit-to-risk ratio of a high-dose strategy at the initiation of mitotane treatment of adrenocortical carcinoma (ACC) remains unknown.

METHODS

To evaluate the performance of a high-dose strategy, defined as the highest tolerated dose administered within 2 weeks and maintenance therapy over 4 weeks, we conducted a single-center, prospective study with two main objectives: to evaluate the percentage of patients who achieve a plasma mitotane level above 14 mg/l and to evaluate the tolerance of mitotane within the first 3 months of treatment. Plasma mitotane levels were measured monthly using HPLC.

RESULTS

Twenty-two patients with ACC were prospectively enrolled. The high-dose mitotane strategy (4 g/day or more in all patients, with a median of 6 g/day within 2 weeks) enabled to reach the therapeutic threshold of >14 mg/l at 1, 2, or 3 months in 6/22 patients (27%), 7/22 patients (32%), and 7/22 patients (32%) respectively. In total, a therapeutic plasma mitotane level was reached in 14 out of 22 patients (63.6%) during the first 3 months in ten patients, and after 3 months in four patients. Grade 3-4 neurological or hematological toxicities were observed in three patients (13.6%).

CONCLUSION

Employing a high-dose strategy at the time of mitotane initiation enabled therapeutic plasma levels of mitotane to be reached within 1 month in 27% of the total group of patients. If this strategy is adopted, we suggest that mitotane dose is readjusted according to plasma mitotane levels at 1 or/and 2 months and patient tolerance.

Hepatic metastasis from adrenocortical carcinoma fifteen years after primary resection

We report the case of a 73-year-old man who presented with an asymptomatic hepatic mass during investigation of mild chronic obstructive pulmonary disease by a plain chest radiograph, followed by ultrasonography, which revealed a solitary hepatic lesion measuring 7.1 cm × 6.5 cm × 5.8 cm in dimension. Fine- needle aspiration of the mass revealed malignant cells compatible with hepatocellular carcinoma. Interestingly, the patient had a left adrenalectomy and complete left nephrectomy in 1987, for a non-functioning left adrenocortical carcinoma (ACC). The ACC was diagnosed as stage two, with no evidence of local invasion or distant metastases. No adjuvant therapy was recommended postoperatively. After a five-year follow-up, there was no evidence of ACC recurrence and the patient was declared cured from his ACC. The patient underwent a complete segmental resection of the right lobe of the liver successfully. The final diagnosis of the mass was a well-differentiated metastatic adrenocortical carcinoma.

Drug interactions with mitotane by induction of CYP3A4 metabolism in the clinical management of adrenocortical carcinoma

Mitotane [1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane, (o,p'-DDD)] is the only drug approved for the treatment for adrenocortical carcinoma (ACC) and has also been used for various forms of glucocorticoid excess. Through still largely unknown mechanisms, mitotane inhibits adrenal steroid synthesis and adrenocortical cell proliferation. Mitotane increases hepatic metabolism of cortisol, and an increased replacement dose of glucocorticoids is standard of care during mitotane treatment. Recently, sunitinib, a multityrosine kinase inhibitor (TKI), has been found to be rapidly metabolized by CYP3A4 during mitotane treatment, indicating clinically relevant drug interactions with mitotane. We here summarize the current evidence concerning mitotane-induced changes in hepatic monooxygenase expression, list drugs potentially affected by mitotane-related CYP3A4 induction and suggest alternatives. For example, using standard doses of macrolide antibiotics is unlikely to reach sufficient plasma levels, making fluoroquinolones in many cases a superior choice. Similarly, statins such as simvastatin are metabolized by CYP3A4, whereas others like pravastatin are not. Importantly, in the past, several clinical trials using cytotoxic drugs but also targeted therapies in ACC yielded disappointing results. This lack of antineoplastic activity may be explained in part by insufficient drug exposure owing to enhanced drug metabolism induced by mitotane. Thus, induction of CYP3A4 by mitotane needs to be considered in the design of future clinical trials in ACC.

Tumores adrenocorticais na criança: da abordagem clínica à avaliação molecular

Tumores do córtex adrenal (TCA) são mais frequentes em crianças, mas podem ocorrer em qualquer faixa etária. São classificados como funcionantes, não funcionantes (predominam no adulto), e mistos. O diagnóstico é baseado na avaliação clínica, hormonal e exames de imagem. Em crianças, o método de escolha para diferenciar entre benigno ou maligno é a classificação baseada no estadiamento do tumor. Alguns marcadores moleculares merecem destaque: além de mutações inativadoras no gene supressor tumoral TP53, há evidências de envolvimento do IGF2 em 90% de TAC malignos, e mutações no éxon 3 do gene CTNNB1 foram encontradas em 6% dos TAC pediátricos. Além disso, microRNAs podem atuar como reguladores negativos da expressão gênica e participar da tumorigênese adrenocortical. Métodos para análise da expressão gênica permitem identificar TCA com prognóstico bom ou ruim, e espera-se que esses estudos possam facilitar o desenvolvimento de drogas para tratar pacientes de acordo com as vias de sinalização específicas que estiverem alteradas.

Contemporary management of adrenocortical carcinoma

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and typically aggressive malignancy. Available recommendations are based primarily on retrospective series or expert opinions, and only few prospective clinical studies have yet been published.

OBJECTIVE

To combine the available evidence for diagnostic work-up and treatment of ACC to a contemporary recommendation on the management of this disease.

EVIDENCE ACQUISITION

We conducted a systematic literature search for studies conducted on humans and published in English using the Medline/PubMed database up to 31 January 2011. In addition, we screened published abstracts at meetings and several Web sites for recommendations on ACC management.

EVIDENCE SYNTHESIS

In patients with suspected localised ACC, a thorough endocrine and imaging work-up is followed by complete (R0) resection of the tumour by an expert surgeon. In experienced hands, laparoscopic adrenalectomy is probably as effective and safe for localised and noninvasive ACC as open surgery. Most clinicians agree that mitotane should be used as adjuvant therapy in the majority of patients, as they have a high risk for recurrence. An international panel has suggested using tumour stage, resection status, and the proliferation marker Ki67 as guidance for or against adjuvant therapy. In patients with advanced disease at presentation or recurrence not amenable to complete resection, a surgical approach is frequently inadequate. In these cases, mitotane alone or in combination with cytotoxic drugs is the treatment of choice. The most promising regimens (etoposide, doxorubicin, cisplatin plus mitotane, and streptozotocin plus mitotane) are currently compared in an international phase 3 trial, and results should be available by the end of 2011. Several targeted therapies are under investigation and may lead to new treatment options. Management of endocrine manifestations with steroidogenesis inhibitors is required in patients suffering uncontrolled hormone excess.

CONCLUSIONS

Detailed recommendations are provided to guide the management of patients with ACC.

Giant non-functioning adrenocortical carcinoma: A rare childhood tumor

Adrenocortical carcinoma (ACC) is a rare malignancy, especially in children. The overall incidence is approximately 2 cases per million per year.[1] In children, the incidence is 0.3 cases per million per year, except in southern Brazil where the incidence is 3.4–4.2 cases per million per year.[2] We describe a giant nonfunctioning metastasized ACC in a 6-year-old girl who presented with a history of increasing abdominal girth incidentally noticed by her mother since 1 week. Ultrasound abdomen showed a large right suprarenal tumor with calcifications and necrosis. Empty left renal fossa and compensatory enlarged right kidney were seen. Computed tomography (CT) scan revealed a large heterogenously enhancing right suprarenal mass with calcification and necrosis with pulmonary metastasis. Histopathology report from the right suprarenal mass revealed an ACC. With a stage IV disease, the patient died after 2 months from diagnosis.

Adrenocortical carcinoma: a clinician's update

Adrenocortical carcinoma is a rare heterogeneous neoplasm with an incompletely understood pathogenesis and a poor prognosis. Previous studies have identified overexpression of insulin-like growth factor 2 (IGF-2) and constitutive activation of β-catenin as key factors involved in the development of adrenocortical carcinoma. Most patients present with steroid hormone excess, for example Cushing syndrome or virilization, or abdominal mass effects, but a growing proportion of patients with adrenocortical carcinoma (currently >15%) is initially diagnosed incidentally. No general consensus on the diagnostic and therapeutic measures for adrenocortical carcinoma exists, but collaborative efforts, such as international conferences and networks, including the European Network for the Study of Adrenal Tumors (ENSAT), have substantially advanced the field. In patients with suspected adrenocortical carcinoma, a thorough endocrine and imaging work-up is recommended to guide the surgical approach aimed at complete resection of the tumor. To establish an adequate basis for treatment decisions, pathology reports include the Weiss score to assess malignancy, the resection status and the Ki67 index. As recurrence is frequent, close follow-up initially every 3 months is mandatory. 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. Results of a large phase III trial in advanced adrenocortical carcinoma are anticipated for 2011 and will hopefully establish a benchmark therapy. New targeted therapies, for example, IGF-1 receptor inhibitors, are under investigation and may soon improve current treatment options.

Transcatheter arterial chemoembolization for liver metastases in patients with adrenocortical carcinoma

PURPOSE

To retrospectively evaluate the effectiveness, tolerance, and predictors of response to transcatheter arterial chemoembolization for treatment of liver metastases from adrenocortical carcinoma.

MATERIALS AND METHODS

Twenty-nine patients with progressive liver metastases from adrenocortical carcinoma were treated with transcatheter arterial chemoembolization. Rate and duration of tumor response were defined according to Response Evaluation Criteria In Solid Tumors. The size of liver metastases, percentage of liver involvement, and Lipiodol uptake were studied as potential predictive factors of response. Time to liver and metastatic lesion progression were considered as endpoints.

RESULTS

Three months after transcatheter arterial chemoembolization, a liver morphologic response was observed in six of 29 patients (21%), stabilization in 18 (62%), and progression in five (17%). According to per-lesion analysis (n = 103), a morphologic response was observed in 23 lesions (22%), stabilization in 67 (65%), and progression in 13 (13%). Higher response rates were observed in cases in which the diameter of the target metastasis was 3 cm or smaller (P = .002) and in cases of high Lipiodol uptake (> 50%; P < .0001). On per-patient and per-lesion bases, progression rates were 32% and 55% at 6 months and 23% and 38% at 12 months. The median time to progression was 9 months and median survival was 11 months after the first procedure.

CONCLUSIONS

Transcatheter arterial chemoembolization should be considered as part of the therapeutic arsenal to treat liver metastases from adrenocortical carcinoma. The size of liver metastases and the percentage of Lipiodol uptake may help identify patients likely to benefit most from transcatheter arterial chemoembolization.

Androgen- and estrogen-secreting adrenal cancers

Androgen-secreting adrenal cancers are extremely rare malignancies, accounting for only a tiny proportion of the total number of women presenting with signs of androgen excess. Estrogen-secreting adrenal cancers are rarer still. Understanding how these tumors work benefits from an appreciation of adrenal steroid biosynthesis, as it is said that secretion in cancers is an anarchic version of normal adrenal function. Selection of patients in whom we should have a high suspicion of a malignancy is vital, so that biochemical investigation and imaging is deployed appropriately. When an adrenal tumor is found to secrete androgens or estrogens to excess, it can be difficult to confirm that it is a cancer, as there is significant overlap in the secretory patterns and imaging appearances of benign and malignant disease. The most reliable indicator of malignancy in these tumors remains the presence of metastases. Treatment is essentially surgical, although the role of mitotane is one undergoing evaluation.

Current and emerging therapies for advanced adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare but aggressive malignancy with a poor prognosis. Complete surgical resection offers the only potential for cure; however, even after apparently successful excision, local or metastatic recurrence is frequent. Treatment options for advanced ACC are severely limited. Mitotane is the only recognized adrenolytic therapy available; however, response rates are modest and unpredictable whereas systemic toxicities are significant. Reported responses to conventional cytotoxic chemotherapy have also been disappointing, and the rarity of ACC had hampered the ability to undertake randomized clinical studies until the establishment of the First International Randomized Trial in Locally Advanced and Metastatic Adrenocortical Carcinoma. This yet-to-be reported study seeks to identify the most effective first- and second-line cytotoxic regimens. The past decade has also seen increasing research into the molecular pathogenesis of ACCs, with particular interest in the insulin-like growth factor signaling pathway. The widespread development of small molecule tyrosine kinase inhibitors in broader oncological practice is now allowing for the rational selection of targeted therapies to study in ACC. In this review, we discuss the currently available therapeutic options for patients with advanced ACC and detail the molecular rationale behind, and clinical evidence for, novel and emerging therapies.

Improved survival in patients with stage II adrenocortical carcinoma followed up prospectively by specialized centers

CONTEXT

Median survival in stage II adrenocortical carcinoma (ACC) differs widely in published series ranging between 23 and more than 60 months. We hypothesized that these results may have been affected by a referral bias because many patients may contact specialized centers only after recurrence.

OBJECTIVE

The objective of the study was a comparison of outcome in patients with stage II ACC who were followed up prospectively early after surgery and were counseled by a specialized center (prospective group) with patients who registered with the German ACC registry later than 4 months after diagnosis (retrospective group).

PATIENTS/METHODS

The study was a cohort analysis in 149 adult patients with stage II ACC.

RESULTS

Patients who were followed up prospectively (n = 30) had a lower recurrence rate and a superior 5-yr survival compared with the 119 patients in the retrospective group (30 vs. 74%, P < 0.01 and 96 vs. 55%, P < 0.05, respectively). In the retrospective group, 67% of the patients had registered only after disease recurrence. In the remaining patients, the recurrence rate was low (21%), and the 5-yr survival was greater than 95%. More patients in the prospective group received adjuvant mitotane (53 vs. 16%, P < 0.001), and adjuvant mitotane was associated with improved survival [hazard risk 0.35 (95% confidence interval 0.13-0.97); P = 0.04]. However, the survival advantage was maintained when only patients without mitotane therapy were analyzed.

CONCLUSIONS

Patients who are followed up prospectively after surgery for stage II ACC and receive early specialized care have a much better prognosis than previously reported due to a major referral bias in previous series and use of adjuvant mitotane. These findings will impact on the perception of prognosis in newly diagnosed stage II ACC.

Adrenocortical tumors with myxoid features: a distinct morphologic and phenotypical variant exhibiting malignant behavior

Myxoid changes have been rarely reported both in adrenocortical adenomas and carcinomas. The recent observation by our group of an adrenal myxoid tumor with morphologically borderline features, but aggressive clinical behavior prompted us to review a series of 196 adrenocortical lesions, comprising 122 carcinomas and 74 adenomas, to define the morphologic, phenotypical and clinical characteristics of adrenocortical tumors with myxoid features. Fourteen cases, including 12 carcinomas and 2 borderline tumors, formed the basis of this report, and were characterized by a variably abundant myxoid component (from 5% to 90% of tumor) and 2 distinct cellular growth patterns: the first (10 cases), mostly associated with a predominant myxoid stromal component, was made of small cells with mild atypia arranged in cords and microcysts; the second (4 cases) was characterized by focal myxoid changes in tumors otherwise similar to conventional adrenocortical carcinoma, with large atypical cells having an eosinophilic cytoplasm and a diffuse or nodular architecture. The above mentioned patterns were absent in all adenomas reviewed. A peculiar reactivity to neurofilaments was seen, mostly associated to the presence of predominant rather that focal myxoid stromal changes, and in 40% of conventional adrenocortical carcinomas, thus representing an undescribed potential pitfall in the differential diagnosis of adrenal lesions. Myxoid adrenocortical tumors probably represent a rare but histologically and phenotipically distinct entity and, although rare cases of benign lesions are on record, they seem to be generally associated to morphologic and clinical features of malignancy.