Cytotoxic treatment of adrenocortical carcinoma

The tyrosine kinase inhibitor nilotinib is more efficient than mitotane in decreasing cell viability in spheroids prepared from adrenocortical carcinoma cells

Background

New drugs for adrenocortical carcinoma (ACC) are needed because most patients undergo rapid disease progression despite surgery and adjuvant therapy with mitotane. In this study, we aimed to investigate the in vitro effects of different chemotherapy drugs, alone or combined with mitotane, on the viability of adrenocortical carcinoma cells.

Methods

Everolimus, sunitinib, zoledronic acid, imatinib and nilotinib cytotoxicity, alone or combined with mitotane were tested on ACC H295R cells in monolayer or spheroid cultures using MTS assays and confocal microscopy. Moreover, the nilotinib effects were investigated in spheroids cultured from patient tumor-derived ACC-T36 cells.

Results

Morphological characterization of H295R cell spheroids using histochemistry was performed and showed that dense, homogenously sized, multicellular spheroids were obtained. We observed that sunitinib and nilotinib alone were equally effective in a monolayer preparation, whereas mitotane was the most effective even at a low dose. A combination of sunitinib and mitotane was the most effective treatment, with only 23.8% of cells in the monolayer remaining viable. Spheroid preparations showed resistance to different drugs, although the poor effect produced by mitotane alone was surprising, with a cell viability of 84.6% in comparison with 13.1% in monolayer cells. The most ineffective drugs in spheroid preparations were everolimus, zoledronic acid and imatinib. In both cell types, nilotinib, either alone or in combination with mitotane induced more significant cell viability inhibition in monolayer and spheroid preparations. In addition, the mechanism of nilotinib activity involves the ERK1/2 pathway.

Conclusion

Taken together, our data identified nilotinib as a cytotoxic drug that combined with ERK inhibitors deserves to be tested as a novel therapy for adrenocortical carcinoma.

Adrenocortical Carcinoma: A Clinician's Perspective

Within the category of orphan diseases and rare malignancies, adrenocortical carcinoma (ACC) represents an aggressive entity with high mortality and morbidity. While localized tumors which are diagnosed early can be cured with surgical intervention, there are prognostic factors which predict for micrometastases and consequent recurrent and advanced disease. In such cases, mitotane and cytotoxic chemotherapy have been utilized with a modest degree of benefit. The poor prognosis of recurrent and advanced ACC has underscored the interest in nuanced characterization of ACC cases to guide the personalized use of immunotherapeutic and novel targeted therapies.

Rapid in-vitro testing for chemotherapy sensitivity in leukaemia patients

Bioluminescent bacterial biosensors can be used in a rapid in vitro assay to predict sensitivity to commonly used chemotherapy drugs in acute myeloid leukemia (AML). The nucleoside analog cytarabine (ara-C) is the key agent for treating AML; however, up to 30 % of patients fail to respond to treatment. Screening of patient blood samples to determine drug response before commencement of treatment is needed. To achieve this aim, a self-bioluminescent reporter strain of Escherichia coli has been constructed and evaluated for use as an ara-C biosensor and an in vitro assay has been designed to predict ara-C response in clinical samples. Transposition mutagenesis was used to create a cytidine deaminase (cdd)-deficient mutant of E. coli MG1655 that responded to ara-C. The strain was transformed with the luxCDABE operon and used as a whole-cell biosensor for development an 8-h assay to determine ara-C uptake and phosphorylation by leukemic cells. Intracellular concentrations of 0.025 μmol/L phosphorylated ara-C were detected by significantly increased light output (P < 0.05) from the bacterial biosensor. Results using AML cell lines with known response to ara-C showed close correlation between the 8-h assay and a 3-day cytotoxicity test for ara-C cell killing. In retrospective tests with 24 clinical samples of bone marrow or peripheral blood, the biosensor-based assay predicted leukemic cell response to ara-C within 8 h. The biosensor-based assay may offer a predictor for evaluating the sensitivity of leukemic cells to ara-C before patients undergo chemotherapy and allow customized treatment of drug-sensitive patients with reduced ara-C dose levels. The 8-h assay monitors intracellular ara-CTP (cytosine arabinoside triphosphate) levels and, if fully validated, may be suitable for use in clinical settings.

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.

The effect of mitotane on viability, steroidogenesis and gene expression in NCI‑H295R adrenocortical cells

Mitotane, also known as o,p'‑DDD or (RS)‑1‑chl-oro‑2‑[2,2‑dichloro‑1‑(4‑chlorophenyl)‑ethyl]‑benzene, is an adrenal cortex-specific cytotoxic drug used in the therapy of adrenocortical carcinoma (ACC). The drug also inhibits steroidogenesis, however, the mechanisms of its anticancer and antisteroidogenic effects remain unknown. At present, data on the impact of mitotane on cell viability and the regulation of genes encoding proteins associated with steroids synthesis in the adrenal cortex, including cortisol and dehydroepiandrosterone sulfate (DHEAS), are limited and contradictory. In the present study, the effect of 24‑h mitotane treatment on viability of the ACC cell line, NCI‑H295R, was analyzed, identifying a decrease in cell viability and an increase in caspase‑3 and ‑7 activities. Mitotane treatment also led to decreased cortisol and DHEAS concentration in the culture media. Concomitantly, mitotane resulted in decreased mRNA levels of two cytochromes P450 (CYP11A1 and CYP17A1), mRNAs encoding proteins involved in the synthesis of cortisol and DHEAS. Mitotane did not affect mRNA levels of cyclin dependent kinase inhibitor 1A (encoding p21) and MYC (encoding cMyc). cMyc and p21 are key transcription factors associated with cell cycle regulation. However, mitotane inhibited expression of transforming growth factor β1 gene, encoding a potent inhibitor of cell proliferation and steroidogenesis. PRKAR1A, a protein kinase A regulatory subunit, is involved in the activation of steroidogenesis. PRKAR1A mRNA levels were reduced following 24‑h treatment with mitotane. Results indicate that mitotane markedly inhibited expression of genes involved in steroidogenesis, secretion of cortisol and DHEAS. Reduced expression of TGFB1 cannot account fully for the effect of mitotane on CYP11A1 and CYP17A1. We hypothesized that reduced viability of NCI‑H295R cells in the presence of mitotane may be a result of apoptosis triggered by increased caspase‑3 and ‑7 activities. Since p21 and cMyc mRNA levels were stable in the presence of mitotane, the mechanism by which caspase‑3 and ‑7 are induced remains unknown.

Dysregulation of microRNAs in adrenocortical tumors

MicroRNAs (miRNAs) are short non-coding RNAs that are involved in the epigenetic regulation of cellular processes. Different malignancies are often associated with the deregulation of specific sets of miRNAs. The prognosis of adrenocortical cancers (ACCs) is very poor as compared to adrenocortical adenomas (ACAs), and even within ACCs there are cases with better disease specific survival. An improved understanding of the pathobiology of this disease will therefore be useful in facilitating better management of ACCs as well as distinguishing high risk versus low risk subgroups. One third of coding genes are regulated by miRNAs and therefore changes in miRNA expression may be associated with cancer development and progression. In this review we summarize the current understanding of miRNAs in adrenocortical tumors, and highlight their potential in differentiating between ACCs and ACAs, risk stratification and prognosis.

Chiral effects in adrenocorticolytic action of o,p'-DDD (mitotane) in human adrenal cells

Adrenocortical carcinoma (ACC) is a rare malignant disease with poor prognosis. The main pharmacological choice, o,p'-DDD (mitotane), produces severe adverse effects. Since o,p'-DDD is a chiral molecule and stereoisomers frequently possess different pharmacokinetic and/or pharmacodynamic properties, we isolated the two o,p'-DDD enantiomers, (R)-(+)-o,p'-DDD and (S)-(-)-o,p'-DDD, and determined their absolute structures. The effects of each enantiomer on cell viability and on cortisol and dehydroepiandrosterone (DHEA) secretion in the human adrenocortical cell line H295R were assessed. We also assayed the o,p'-DDD racemate and the m,p'- and p,p'-isomers. The results show small but statistically significant differences in activity of the o,p'-DDD enantiomers for all parameters tested. The three DDD isomers were equally potent in decreasing cell viability, but p,p'-DDD affected hormone secretion slightly less than the o,p'- and m,p'-isomers. The small chiral differences in direct effects on target cells alone do not warrant single enantiomer administration, but might reach importance in conjunction with possible stereochemical effects on pharmacokinetic processes in vivo.

Surgical approach to a large left adrenocortical mass with associated tumour thrombosis of the left renal vein: preservation of the ipsilateral kidney

A sixty-years-old male with diagnosis of a left adrenal mass (146 × 99 × 126 mm) with associated tumour thrombosis of the left renal vein with no clear signs of thrombosis of the inferior vena cava was admitted for elective surgery Finally an adrenalectomy and excision of tumour thrombus preserving the ipsilateral kidney was made. Despite of the complex vascular management, this kind of approaches allow to preserve normal renal function in patients with future nephrotoxic treatment like cisplatin.

Molecular markers and the pathogenesis of adrenocortical cancer

Adrenal tumors are common, with an estimated incidence of 7.3% in autopsy cases, while adrenocortical carcinomas (ACCs) are rare, with an estimated prevalence of 4-12 per million population. Because the prognoses for adrenocortical adenomas (ACAs) and ACCs are vastly different, it is important to be able to accurately differentiate the two tumor types. Advancement in the understanding of the pathophysiology of ACCs is essential for the development of more sensitive means of diagnosis and treatment, resulting in better clinical outcome. Adrenocortical tumors (ACTs) occur as a component of several hereditary tumor syndromes, which include the Li-Fraumeni syndrome, Beckwith-Wiedemann syndrome, multiple endocrine neoplasia 1, Carney complex, and congenital adrenal hyperplasia. The genes involved in these syndromes have also been shown to play a role in the pathogenesis of sporadic ACTs. The adrenocorticotropic hormone-cAMP-protein kinase A and Wnt pathways are also implicated in adrenocortical tumorigenesis. The aim of this review is to summarize the current knowledge on the molecular mechanisms involved in adrenocortical tumorigenesis, including results of comparative genomic hybridization, loss of heterozygosity, and microarray gene-expression profiling studies.

Treatment of advanced adrenocortical carcinoma with erlotinib plus gemcitabine

CONTEXT

Adrenocortical carcinoma (ACC) is a rare malignancy with poor prognosis. In advanced disease, mitotane given as monotherapy or combined either with etoposide, doxorubicin, and cisplatin or with streptozotocin is the recommended first-line therapy. However, many patients have progressive disease despite treatment with these regimens.

OBJECTIVE

Our objective was to evaluate the efficacy of the epidermal growth factor receptor inhibitor erlotinib plus gemcitabine as salvage therapy in ACC patients with very advanced ACC.

DESIGN/SETTING

The study consisted of case series collected from different centers (primary care and referral centers) in Germany in 2006-2007.

PATIENTS AND INTERVENTION

Patients registered with the German ACC Registry with progressive ACC after two to four previous systemic therapies were offered treatment with erlotinib and gemcitabine. Oral erlotinib (100 mg/d) was administered on a daily basis and gemcitabine (800 mg/m(2)) iv every 14 d.

MAIN OUTCOME MEASURE

We evaluated tumor response according to response evaluation criteria in solid tumors (RECIST) criteria after 12 wk of treatment.

RESULTS

Ten patients have been treated with erlotinib and gemcitabine. Only one in 10 patients experienced a minor response (progression-free survival 8 months), whereas eight patients had progressive disease at the first staging. One patient had to stop therapy after the first administration of gemcitabine due to cerebral seizure. Nine of 10 patients had died after a median of 5.5 months after treatment initiation. In addition to the seizure, one patient experienced severe pneumonia (grade III), and in one, gemcitabine administration had been delayed due to prolonged neutropenia. All other adverse events were mild (grade I-II).

CONCLUSIONS

Salvage chemotherapy using erlotinib plus gemcitabine has very limited to no activity in patients with very advanced ACC.

Adrenal incidentalomas: presentation and clinical work-up

BACKGROUND

Through the widespread use of imaging techniques with great sensitivity, adrenal tumours are often diagnosed as an incidental finding. The majority of these adrenal lesions are benign and without evidence of endocrine activity or malignancy. However, in addition to the classic forms of overt adrenal hypersecretion, it has become evident in recent years that even modest adrenal hormonal autonomy, as exhibited in clinically silent phaeochromocytoma, normokalaemic primary aldosteronism and subclinical Cushing syndrome, is associated with significant morbidity. Thus, hormone hypersecretion and growth kinetics must be ruled out for each patient using specific tests to avoid associated morbidity.

CONCLUSIONS

Detection and differential diagnosis of subtle changes in adrenal hormone secretion can pose a diagnostic challenge to the clinician, and accurate diagnosis is dependent on use of tests with reliable sensitivity and specificity.

Diagnosis and management of adrenal cortical carcinoma

Adrenal cortical carcinoma is a relatively uncommon malignancy that represents a significant clinical challenge for the development of optimal treatment strategies. Historically, successful treatment has relied upon rapid identification of the lesion, accurate staging with diagnostic imaging, and complete surgical extirpation. Although the framework of a successful treatment paradigm still relies on these steps, advances in diagnostic imaging have led to increased accuracy in diagnosis, and advances in laparoscopic surgical technique have served to reduce morbidity for patients facing treatment. This review focuses on a discussion of advances in modalities for the diagnosis and treatment of adrenal cortical carcinoma amenable to curative therapy. Patients that present with metastatic or locally advanced disease generally are treated with mitotane-based chemotherapy with or without the addition of cytotoxic drugs. Contemporary results of this treatment approach are presented in this review as well as a discussion of further directions for the treatment of patients with advanced disease.

Adrenocortical tumorigenesis, luteinizing hormone receptor and transcription factors GATA-4 and GATA-6

Luteinizing hormone (LH/hCG) responsiveness of normal and pathological human adrenal glands as well as the possibility of constitutive expressions of luteinizing hormone receptor (LHR) in adrenal cortex has been reported. Some recent studies showed a correlation between the LHR and abundant GATA-4 expression in both metastasizing and non-metastasizing human adrenocortical tumors, but not in normal adrenals, implicating the putative relevance of LHR and GATA-4 for adrenocortical pathophysiology. However, the physio- and pathophysiological significance of LHR and GATA-4 in the mechanism of adrenocortical tumorigenesis remains unclear. The paucity of suitable models for adrenal tumorigenesis makes the establishment of proper animal models highly important. LHR expression in the murine adrenal gland is an exception and not found in wild-type (WT) animal. We have previously shown that ectopic LHR expression in the murine adrenal gland can be induced by chronically elevated LH levels. We have generated a gonadotropin-responsive adrenal tumor model in gonadectomized transgenic (TG) mice expressing the inhibin alpha promoter/Simian Virus 40 T antigen transgene (inhalpha/Tag). Given the induction of expression and regulation of GATA-4 and GATA-6 zinc finger transcription factors in the gonads by gonadotropins, this review will explore their relationship to LHR expression and their role in adrenocortical tumorigenesis. A functional link between LHR and GATA-4 actions in the adrenal pathophysiology is proposed.

Adrenal toxicology: a strategy for assessment of functional toxicity to the adrenal cortex and steroidogenesis

The adrenal is the most common toxicological target organ in the endocrine system in vivo and yet it is neglected in regulatory endocrine disruption screening and testing. There has been a recent marked increase in interest in adrenal toxicity, but there are no standardised approaches for assessment. Consequently, a strategy is proposed to evaluate adrenocortical toxicity. Human adrenal conditions are reviewed and adrenocortical suppression, known to have been iatrogenically induced leading to Addisonian crisis and death, is identified as the toxicological hazard of most concern. The consequences of inhibition of key steroidogenic enzymes and the possible toxicological modulation of other adrenal conditions are also highlighted. The proposed strategy involves an in vivo rodent adrenal competency test based on ACTH challenge to specifically examine adrenocortical suppression. The H295R human adrenocortical carcinoma cell line is also proposed to identify molecular targets, and is useful for measuring steroids, enzymes or gene expression. Hypothalamo-pituitary-adrenal endocrinology relevant to rodent and human toxicology is reviewed (with an emphasis on multi-endocrine axis effects on the adrenal and also how the adrenal affects a variety of other hormones) and the endocrinology of the H295R cell line is also described. Chemicals known to induce adrenocortical toxicity are reviewed and over 60 examples of compounds and their confirmed steroidogenic targets are presented, with much of this work published very recently using H295R cell systems. In proposing a strategy for adrenocortical toxicity assessment, the outlined techniques will provide hazard assessment data but it will be regulatory agencies that must consider the significance of such data in risk extrapolation models. The cases of etomindate and aminoglutethimide induced adrenal suppression are clearly documented examples of iatrogenic adrenal toxicity in humans. Environmentally, sentinel species, such as fish, have also shown evidence of adrenal endocrine disruption attributed to exposure to chemicals. The extent of human sub-clinical adrenal effects from environmental chemical exposures is unknown, and the extent to which environmental chemicals may act as a contributory factor to human adrenal conditions following chronic low-level exposures will remain unknown unless purposefully studied.

Adrenocortical Tumorigenesis

Through the widespread use of imaging techniques with great sensitivity adrenal tumors are often diagnosed as an incidental finding. Although the majority of these adrenal lesions are benign and without evidence of endocrine activity or malignancy, hormone hypersecretion needs to be ruled out by specific tests. In addition to the classical forms of overt adrenocortical hypersecretion, it has become evident over the recent years that modest adrenocortical steroid autonomy as present in normokalemic primary aldosteronism and subclinical Cushing's syndrome is also associated with a significant morbidity. However, detection and differential diagnosis of these subtle changes in adrenal steroidogenesis can pose a diagnostic challenge to the clinician and is dependent on tests with reliable sensitivity and specificity. Regulation of adrenocortical development and growth, which results in clinical symptoms if disrupted, is dependent upon the distinct spatiotemporal expression of a variety of transcription factors as well as stimulation by extra-adrenal peptide hormones. Contributions to the elucidation of growth regulation of the adrenal cortex come from rare familiar syndromes associated with adrenocortical tumors, expression studies of adrenal tumor samples, in vitro studies on adrenocortical tumor cell lines, and mouse models displaying adrenal growth defects. In this review, we will summarize the important molecular aspects of adrenal tumorigenesis and highlight some prospects for clinical applications.

Dendritic cells as potential adjuvant for immunotherapy in adrenocortical carcinoma

OBJECTIVE

Adrenocortical carcinoma (ACC) is a rare malignancy associated with a dismal prognosis. Dendritic cells (DCs) are professional antigen-presenting cells leading to an antitumour immune response. The aim of this study was to elaborate two methods of antigen delivery to DCs and to evaluate an immunotherapy protocol in ACC patients.

DESIGN/PATIENTS

Autologous DCs were pulsed with autologous tumour lysate (TL). Fusion of DCs with tumour cells was based on a polyethylene glycol method. Two patients with metastasized hypersecretory ACC were vaccinated twice.

MEASUREMENTS

In vitro data were quantified by measurement of PBMC (peripheral blood mononuclear cell) responses and cytokine secretion and by flow cytometry analyses. Clinical response was monitored by CT scan of tumour mass and measurement of angiogenic factors.

RESULTS

The maximum loading of TL was obtained at 24 h as 48.2% (+/- 26.8%) of DCs were TL-positive. The DC/tumour cell fusion efficacy was approximately 45% as shown by double positive staining for ACTH receptor and DC-specific CD83. In vivo DC vaccination resulted in positive delayed-type hypersensitivity skin reactions reflecting specific memory T-lymphocyte reaction. In vitro analyses revealed specific T-cell proliferation in patient 1 (stimulation index: 5.7 compared to pretreatment) and induction of cytotoxic granzyme B secreting T cells in patient 2 (0.41% CD8 + cells vs. 0.06% pretreatment) as indicators of specific cytotoxic T cells. Although angiogenic serum markers could be stabilized, no impact on tumour growth could be observed.

CONCLUSION

Our data demonstrate that autologous dendritic cells induce antigen-specific Th1 immunity in adrenocortical carcinoma. The clinical outcome, however, was not improved in the patients studied here.

Adrenocortical carcinoma

PURPOSE OF REVIEW

Adrenocortical carcinoma is a rare malignancy, accounting for 0.02% of all annual cancers reported. Given the generally advanced stage at diagnosis, the overall 5-year survival remains poor, varying between 20 and 45%. While older studies purported an improved outcome for functional tumors in adult patients, this has not been borne out in more recent studies. In the pediatric population, though, virilizing tumors carry a better survival than non-functional or cortisol-secreting tumors.

RECENT FINDINGS

Recent studies focusing on the tumorigenesis of adrenocortical carcinoma have focused on onco-developmental genes present in the fetal adrenal cortex, as well as local adrenal paracrine and autocrine effects of cellular peptides.

SUMMARY

Pre-operative diagnostic advances in positron emission scanning are emerging as promising modalities for confirmation of malignancy of indeterminate adrenal masses. No significant advances in the treatment of adrenocortical carcinoma have been developed. Surgery remains the mainstay for primary and recurrent disease, including select patients with isolated liver metastases. Mitotane has remained the preferred adjuvant treatment agent, showing modest effect in patients with unresectable, residual or metastatic disease. Multi-institutional registries and trials need to be established, with multidisciplinary efforts focused on the development of new therapeutic strategies.

Clinical review: Adrenocortical carcinoma: clinical update

CONTEXT

Adrenocortical carcinoma (ACC) is a rare and heterogeneous malignancy with incompletely understood pathogenesis and poor prognosis. Patients present with hormone excess (e.g. virilization, Cushing's syndrome) or a local mass effect (median tumor size at diagnosis > 10 cm). This paper reviews current diagnostic and therapeutic strategies in ACC.

EVIDENCE ACQUISITION

Original articles and reviews were identified using a PubMed search strategy (http://www.ncbi.nlm.nih.gov/entrez/query.fcgi) covering the time period up until November 2005. The following search terms were used in varying combinations: adrenal, adrenocortical, cancer, carcinoma, tumor, diagnosis, imaging, treatment, radiotherapy, mitotane, cytotoxic, surgery.

EVIDENCE SYNTHESIS

Tumors typically appear inhomogeneous in both computerized tomography and magnetic resonance imaging with necroses and irregular borders and differ from benign adenomas by their low fat content. Hormonal analysis reveals evidence of steroid hormone secretion by the tumor in the majority of cases, even in seemingly hormonally inactive lesions. Histopathology is crucial for the diagnosis of malignancy and may also provide important prognostic information. In stages I-III open surgery by an expert surgeon aiming at an R0 resection is the treatment of choice. Local recurrence is frequent, particularly after violation of the tumor capsule. Surgery also plays a role in local tumor recurrence and metastatic disease. In patients not amenable to surgery, mitotane (alone or in combination with cytotoxic drugs) remains the treatment of choice. Monitoring of drug levels (therapeutic range 14-20 mg/liter) is mandatory for optimum results. In advanced disease, the most promising therapeutic options (etoposide, doxorubicin, cisplatin plus mitotane, and streptozotocin plus mitotane) are currently being compared in an international phase III trial (www.firm-act.org). Adjuvant treatment options after complete tumor removal (e.g. mitotane, radiotherapy) are urgently needed because postoperative disease-free survival at 5 yr is only around 30%, but options have still not been convincingly established. National registries, international cooperations, and trials provide important new structures for patients but also for researchers aiming at systematic and continuous progress in ACC. However, future advances in the management of ACC will mainly depend on a better understanding of the molecular pathogenesis facilitating the use of modern cancer treatments (e.g. tyrosine kinase inhibitors).

Childhood adrenocortical tumours: a review

Childhood adrenocortical tumour (ACT) is not a common disease, but in southern Brazil the prevalence is 15 times higher than in other parts of the world. One hundred and thirty-seven patients have been identified and followed by our group over the past four decades. Affected children are predominantly girls, with a female-to-male ratio of 3.5:1 in patients below 4 years of age. Virilization alone (51.6%) or mixed with Cushing's syndrome (42.0%) was the predominant clinical picture observed in these patients. Tumours are unilateral, affecting both glands equally. TP53 R337H germline mutations underlie most childhood ACTs in southern Brazil. Epidemiological data from our casuistic studies revealed that this mutation has ~10% penetrance for ACT. Surgery is the definitive treatment, and a complete resection should always be attempted. Although adjuvant chemotherapy has shown some encouraging results, its influence on overall outcome is small. The survival rate is directly correlated to tumour size; patients with small, completely excised tumours have survival rates close to 90%, whereas in those patients with inoperable tumours and/or metastatic disease it is less than 10%. In the group of patients with large, excisable tumours, half of them have an intermediate outcome. Recent molecular biology techniques and genomic approaches may help us to better understand the pathogenesis of ACT, the risk of developing a tumour when TP53 R337H is present, and to predict its outcome. An ongoing pilot study consisting of close monitoring of healthy carriers of the TP53 R337H mutation - siblings and first-degree relatives of known affected cases - aims at the early detection of ACTs and an improvement of the cure rate.

Adrenocortical carcinoma extending into the inferior vena cava: Presentation of a 15-patient series and review of the literature

BACKGROUND

Involvement of the inferior vena cava (IVC) is a controversial risk factor for surgical treatment of adrenocortical carcinoma (ACC). This study aims to assess the outcome of an aggressive surgical policy for ACC extending into the IVC and discuss treatment strategies based on a review of the literature.

METHODS

Over a 25-year period, 15 patients were treated for ACC extending into the IVC. The upper limit of the extension was the infrahepatic IVC in 2 patients, retrohepatic IVC in 6, and suprahepatic IVC in 7, including 4 with extension into the right atrium. Seven patients presented with concurrent metastases. The operative technique was thrombectomy (n = 13), partial resection with direct closure (n = 1), and total resection with replacement of the IVC (n = 1). Venous control was achieved by caval clamping alone (n = 4), hepatic vascular exclusion (n = 5), and the use of normothermic cardiopulmonary bypass or hypothermic circulatory arrest (n = 6).

RESULTS

Two patients died postoperatively. Ten patients died of metastatic complications at 4 to 31 months. Median survival time was 8 months. Three patients were still alive after 24, 25, and 45 months of follow-up, one of whom was reoperated at 17 months for a local recurrence. No evidence of recurrent intravenous involvement was found during follow-up in any patient in whom complete resection was achieved.

CONCLUSIONS

Our findings suggest that surgical treatment can be effective for management of ACC with extension into the IVC. Long-term prognosis is poor owing to delay in diagnosis, frequent associated metastatic disease and lack of effective adjuvant treatment.

Andrenocortical carcinomas: twelve-year prospective experience

Adrenocortical carcinoma (AC) is a rare tumor with poor prognosis. Twenty-two patients (14 F, 8 M; age 22 to 59 years; median, 43 years) with AC were evaluated prospectively in a single center: tumor stage was I-II in 12 cases and III-IV in 10. The overall survival in our cohort was 41.6 +/- 42 months; 16 subjects are still alive. Curative surgery was followed by longer survival than debulking or no surgery (p < 0.0001). The first relapse was highly predictive for further recurrences. Recurrent ACs were progressively more aggressive, and they occurred with variable but ever shorter intervals. At diagnosis, 14 patients (63.5%) presented with features of clear adrenocortical hyperactivity. Despite the absence of clinical signs of hormonal excess, all other patients presented some abnormalities of steroid secretion. The most common clinical finding was a recent diagnosis of moderate-to-severe hypertension (68%), poorly controlled by pharmacological treatment, often associated with multiple cardiovascular risk factors. High mitotic rate and undifferentiated polymorph cellular pattern were associated with worse prognosis. Response to treatments other than surgery (mitotane chemotherapy) was better in patients treated early after the first surgery. In conclusion, curative surgery was the most effective treatment. Monitoring arterial pressure, endocrine parameters, and metabolic parameters can be helpful for the early detection of AC recurrences.

Protection of platinum-DNA adduct formation and reversal of cisplatin resistance by anti-MRP2 hammerhead ribozymes in human cancer cells

Resistance to platinum-containing antineoplastic drugs is the major limitation in their clinical use. To elucidate the role of the ABC transporter MRP2 in platinum drug resistance, its expression was analyzed in human cisplatin-resistant cell lines: the ovarian carcinoma line A2780RCIS, the adrenocortical carcinoma line D43/86RCIS and the melanoma line MeWoCIS1. All these cells showed overexpression of MRP2. For reversal of platinum resistance, 2 anti-MRP2 hammerhead ribozymes were introduced into A2780RCIS cells. Both ribozymes showed gene-silencing activities and reversed the drug-resistant phenotype. Moreover, formation of platinum-induced intrastrand cross-links was measured in DNA. The level of DNA platination corresponded inversely to the level of MRP2 expression and was accompanied by increased caspase-3-dependent apoptosis. Kinetics of formation and elimination of platinum-DNA adducts suggest that the DNA repair capacity was not altered; the decrease in platinum-DNA adduct formation was rather a reflection of the protecting activity of MRP2. In conclusion, functional inhibition of MRP2 might be a promising strategy in the reversal of resistance to platinum-based anticancer drugs. This was reflected by the specific inhibition of MRP2 by ribozyme technology, indicating that this gene therapeutic approach may be applicable as a specific means to overcome platinum resistance in human neoplasms.

Adrenocortical Carcinoma: A Single Institution Experience

Adrenocortical carcinoma (ADCC) ranks among the least common malignant endocrine tumors. Surgical resection is considered the most important treatment for this neoplasm. Medical records of patients with the diagnosis of ADCC between 1990 and 2000 were reviewed. Patient and pathologic factors were analyzed with overall survival as the primary endpoint. Statistical analysis was performed by the method of Kaplan-Meier. There were a total of 17 patients, with a mean age of 56 years. Twelve per cent presented as an asymptomatic mass, 41 per cent as a functional tumor, and 47 per cent as a nonfunctioning tumor. Primary treatment was surgical resection in 71 per cent. There was no operative mortality and one complication. Seven patients presented with stage II, five with stage III, four with stage IV, and in one could not be determined. Median follow-up was 12.8 months, median survival 67, 13, and 3 months for stages II, III, and IV, respectively. Older age, distant metastasis, nonoperative management, positive margins, advanced tumor stage, and venous invasion were significantly associated with worse overall actuarial survival. Survival for ADCC is poor. Factors associated with a worse prognosis were stage of disease, nonoperative management, positive surgical margins, vascular invasion, and older age.

Vincristine, cisplatin, teniposide, and cyclophosphamide combination in the treatment of recurrent or metastatic adrenocortical cancer

The efficacy and tolerability of a combination of vincristine, cisplatin, teniposide, and cyclophosphamide (OPEC) in 11 patients (median age, 45 yr) with recurrent and/or metastatic adrenocortical cancer (ACC) (seven functional and four nonfunctional) were evaluated. All patients received this regimen after the failure of streptozocin and o,p'-DDD (SO) combination therapy. The regimen comprised cyclophosphamide, 600 mg/m2, and vincristine, 1.5 mg/m2, maximum dose 2.0 mg (d 1); cisplatin, 100 mg/m2 (d 2) and teniposide, 150 mg/m2 (d 4). Cycles were repeated every 4 wk. One to eight cycles (median, six cycles) of OPEC were administered to each patient. The median duration of treatment was 6 mo. The overall 2-yr survival rate was 82% and the median survival since diagnosis was 44 mo while it was 21 mo since start of OPEC therapy. Responses were obtained in nine patients: partial response in two patients, and stable disease in seven patients. The median duration of response was 6.75 mo. A total of 60 cycles of chemotherapy were given to all patients; grade 1-2 toxicity occurred in 57 cycles, while grade 3 toxicity was observed only in two cycles, according to NCI's Common Toxicity Criteria. We conclude that the OPEC regimen may be considered in recurrent or metastatic ACC as a second-line medical treatment. However, the combination is accompanied by considerable side effects and dose modifications are necessary in order to be able to recommend the treatment. This regimen needs further evaluation compared with SO therapy preferably in a randomized multicenter trial.

Steroidogenic acute regulatory (StAR)-directed immunotherapy protects against tumor growth of StAR-expressing Sp2-0 cells in a rodent adrenocortical carcinoma model

Adrenocortical carcinoma (ACC) is a highly malignant tumor with poor response to classical antitumor therapy. Steroidogenic acute regulatory (StAR) protein is expressed in most human ACCs. The aim of this study was to induce antitumoral T cells directed against StAR in a murine tumor model. Because a suitable syngenic adrenocortical mouse tumor model is lacking, we established a clone of the mouse myeloma Sp2-0 tumor cell line stably expressing murine StAR (Sp2-mStAR). Using repeated im injections of plasmid DNA encoding mStAR followed by infection with a recombinant vaccinia virus (rVV) expressing mStAR, we induced a cytotoxic T-cell response as measured by enzyme-linked immunospot assay. To demonstrate antitumor activity of the vaccination procedure, mice were treated as follows: group A, mice immunized with plasmids and rVV encoding mStAR receiving Sp2-mStAR cells; control group B, mice immunized with the empty plasmid and the empty rVV receiving Sp2-mStAR cells; control group C, mice immunized with the empty plasmid and rVV encoding P450 side-chain cleavage enzyme receiving Sp2-mStAR cells; and control group D, mice immunized with plasmid and rVV encoding mStAR receiving parental Sp2-0 cells. A high proportion (89-100%) of the control groups B, C, and D developed subcutaneous tumors. In contrast, immunization specific for mStAR (group A) was highly protective against tumor growth (percentage of tumor-free animals, 67%; P < 0.001 vs. controls). In summary, these results show that T-cell tolerance toward mStAR can be broken, resulting in antitumoral immunity. Thus, StAR represents a candidate target antigen for immunotherapeutic strategies against ACC.

Management of adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is a rare neoplasm with poor prognosis. Patients present with signs of steroid hormone excess (e.g. Cushing's syndrome, virilization) or an abdominal mass. Tumour size at presentation (mean diameter at diagnosis > 10 cm) is the most important indicator of malignancy. In addition, computed tomography (CT) typically demonstrates an inhomogeneous adrenal lesion with irregular margins and variable enhancement of solid components after intravenous contrast media. Magnetic resonance imaging (MRI) is equally effective as CT and is particularly helpful to visualize invasion into large vessels. Complete tumour removal (R0 resection) offers by far the best chance for long-term survival and therefore surgery is the treatment of choice in stage I-III ACC. Despite tumour resection for cure most patients will eventually develop local recurrence or distant metastases. Thus adjuvant treatment options need to be evaluated in high-risk patients (e.g. radiation therapy of the tumour bed and/or chemotherapy). In tumour recurrence re-operation should always be considered. In metastatic disease (stage IV ACC) not amenable to surgery mitotane (o,p'DDD) remains the first-line therapy. Drug monitoring is needed for effective treatment aiming at concentrations between 14 and 20 mg/l. Patients not responding to mitotane may benefit from cytotoxic chemotherapy (23% partial remissions, 4% complete remissions). Only large prospective multicentre trials comparing different treatment options will allow to make systematic progress in the management of ACC.

Adrenocortical cancer: recent clinical and molecular advances

PURPOSE OF REVIEW

Adrenocortical cancer (ACC) is an uncommon disorder that remains a challenge to the surgeon and oncologist. When the disease is localized to the adrenal gland and readily amenable to surgical resection, reasonable 5-year survival rates are possible. Locally invasive disease carries a poorer prognosis, and metastatic disease is uniformly fatal within 1 year. In this review, we summarize the current knowledge regarding the clinical management of ACC and the molecular mechanisms underlying the disease.

RECENT FINDINGS

The clinical manifestations, staging, and current treatment for ACC has been well documented. Surgery is still the mainstay of treatment, but identifying molecular targets for chemotherapeutic agents or monoclonal antibodies would be a great advance. At present, our understanding of pathogenic mechanisms is crude; however, the molecular events regulating this aggressive disease are beginning to emerge, especially in the last few years. The advent of laparoscopic adrenalectomy has also created its own dilemmas regarding the appropriate surgical approach to the large, potentially malignant adrenal mass.

SUMMARY

The challenge in the management of this disease lies in understanding the molecular mechanisms that underlie the development of ACC with the diagnostic and therapeutic benefits that would ensue.

Clinical and molecular aspects of adrenocortical tumourigenesis

Adrenal masses are a common problem affecting 3-7% of the population. The majority turn out to be benign adrenocortical adenomas, which may be functional or non-functional. Much more rarely, these masses represent a primary adrenal carcinoma. It is becoming increasingly recognized that of the benign functioning adenomas or hyperplasias, the majority will hypersecrete aldosterone and this will be more frequently detected when hypertensive populations are screened for this disease. In contrast, the incidence of primary adrenocortical carcinoma has remained steady and for this disease, surgery represents the mainstay of treatment. The advent of laparoscopic adrenal surgery has lowered the threshold size for recommending surgery for asymptomatic adrenal masses and as such, an increased proportion of adrenocortical cancers are being resected and detected at an earlier stage. Recent progress has been made in our understanding of the key genetic changes which underpin the biology of this disease. Progression from adrenal adenoma to carcinoma involves a monoclonal proliferation of cells which, among other defects, have undergone chromosomal duplication at the 11p15.5 locus leading to overexpression of the IGF2 gene and abrogation of expression of the CDKN1C and H19 genes. TP53 is involved in progression to carcinoma in a subset of patients and the frequency of ACTH receptor deletion needs to be more fully explored. Other key oncogenes and tumour suppressor genes remain to be identified although the chromosomal loci in which they lie can be identified at 17p, 1p, 2p16 and 11q13 for tumour suppressor genes and chromosomes 4, 5 and 12 for oncogenes.

Laparoscopic adrenalectomy--indications and technique

Laparoscopic adrenalectomy has become the procedure of choice for the surgical management of most adrenal tumors, including functional and non-functional lesions. The role of laparoscopic adrenalectomy in the management of malignant adrenal tumors is controversial and most adrenocortical cancers are generally treated by open adrenalectomy. Laparoscopic adrenalectomy can be performed by both the anterior or lateral trans-abdominal approach and by the lateral or posterior retro-peritoneal approach, with each method being suitable for specific indications. Although there are no randomized trials comparing laparoscopic with open adrenalectomy, the laparoscopic approach is associated with shorter hospital stay, reduced pain and improved cosmesis. This review discusses the indications and contraindications, technique and outcomes for laparoscopic adrenalectomy.

Expression and function of classical protein kinase C isoenzymes in gastric cancer cell line and its drug-resistant sublines

AIM: To investigate the expression and function of classical protein kinase C (PKC) isoenzymes in inducing MDR phenotype in gastric cancer cells.

METHODS: Two cell lines were used in the study: gastric cancer cell SGC7901 and its drug-resistant cell SGC7901/VCR stepwise-selected by vincristine 0.3, 0.7 and 1.0 mg·L^-1, respectively. The expression of classical PKC (cPKC) isoenzymes in SGC7901 cells and SGC7901/VCR cells were detected using immunofluorescent cytochemistry, laser confocal scanning microscope and Western blot. The effects of anti-PKC isoenzymes antibody on adriamycin accumulation in SGC7901/VCR cells were determined using flow cytometric analysis.

RESULTS: (1) SGC7901 cells exhibited positive staining of PKC-α. SGC7901/VCR cells exhibited stronger staining of PKC-α than SGC7901 cells. The higher dosage vincristine selected, the much stronger staining of PKC-α was observed on SGC7901/VCR cells. (2) Both SGC7901 and SGC7901/VCR cells exhibited positive staining of PKC-β I and PKC-β II with no significant difference. (3) Compared with SGC7901, SGC7901/VCR cells had decreased adriamycin accumulation and retention. Accumulation of adriamycin in SGC7901 was 5.21 ± 2.56 mg·L^-1, in SGC7901/VCR 0.3 was 0.85 ± 0.29 mg·L^-1, in SGC7901/VCR 0.7 was 0.81 ± 0.32 mg·L^-1, and in SGC7901/VCR 1.0 was 0.80 ± 0.33 mg·L^-1; Retention of adriamycin in SGC7901 was 2.51 ± 1.23 mg·L^-1, in SGC7901/VCR 0.3 was 0.47 ± 0.14 mg·L^-1, in SGC7901/VCR 0.7 was 0.44 ± 0.15 mg·L^-1, and in SGC7901/VCR 1.0 was 0.41 ± 0.11 mg·L^-1. (4) Fluorescence intensity presented adriamycin accumulation in SGC7901/VCR cells was increased from 1.14 ± 0.36 to 2.71 ± 0.94 when cells were co-incubated with anti-PKC-α but not with anti-PKC-β I, PKC-α II and PKCγ antibodies.

CONCLUSION: PKC-α, but not PKC-β I, PKC-β II or PKCγ, may play a role in multidrug resistance of gastric cancer cells SGC7901/VCR.

Signaling pathways in adrenocortical cancer

Adrenocortical carcinoma is a rare tumor that carries a very poor prognosis. Despite efforts to develop new therapeutic regimens to treat this disease, surgery remains the mainstay of treatment. Laboratory studies of adrenocortical cancers have revealed a wide variety of signaling pathways that can be altered in these neoplasms. Although ACTH signaling through adenylyl cyclase and protein kinase A is important for normal adrenal cellular physiology, there is evidence to suggest that this pathway may inhibit the growth of adrenocortical tumors, and that inactivation of the ACTH receptor may promote tumor formation. Although multiple signal transduction pathways are essential for normal adrenal growth and hormone secretion, efforts to identify events required for neoplastic transformation have met with limited success. Alterations that have frequently been observed in adrenocortical carcinoma include up-regulation of the IGF-II system, as well as mutations in TP53 and RAS. Current studies aim to elucidate the mechanisms of tumor growth by studying proproliferative signaling pathways, such as those involving Akt/PKB and the mitogen-activated protein kinases (MAPKs). Although studies of single pathways have been helpful in guiding investigations, new tools to study the integration and multiplicity of signaling pathways hold the hope of improved understanding of the signaling pathway alterations in adrenocortical cancer.

[Adrenocortical carcinoma: prognostic factors for local recurrence and indications for reoperation. A report on a series of 22 patients]

STUDY AIMS

The aim of this retrospective study was to identify prognostic factors on local recurrence in patients with adrenocortical carcinoma and to assess the effect of reoperations.

METHODS

From 1985 to 2001, 22 patients were operated for adrenocortical carcinoma. We evaluated the correlation between actuarial survival without local recurrence and tumor staging, Weiss criteria, mitotic index, extensive resection and Op'DDD therapy by univariate analysis. Then we evaluated the effect of reoperations on survival.

RESULTS

Local recurrence was observed in 7 patients and the 5-years actuarial survival without local recurrence was 50%. Tumor stage (I et II versus III et IV), Weiss criteria (< or = 6 criteria versus > 6) and mitotic index (< or = 20 mitoses/50 HPF versus > 20) affected survival without local recurrence. Extensive resection could reduce local recurrence rate. Op'DDD therapy was ineffective in prolonging survival without local recurrence. Four patients underwent repeat resections: 2 patients were still alive with disease free, 54 and 8 months after reoperations and 2 patients died, 19 and 25 months after reoperations. Three patients did not have repeat resection. They rapidly died within 8 months.

CONCLUSION

Pathologic features (tumor staging and mitotic index) affected local recurrence prognostic. But extensive resection to adjacent organs could facilitate complete resection tumor and reduce the local recurrence rate. Complete repeat resection of local recurrence can improve survival. The disabling effects of Op'DDD were important and its efficacy was not clear.

N-cadherin expression in adrenal tumors: upregulation in malignant pheochromocytoma and downregulation in adrenocortical carcinoma

Cell adhesion molecules (CAMs) are important regulators of tumor growth. The aim of the present study was to evaluate the expression pattern of CAMs in adrenal tumors regarding origin (cortex vs medulla) and biologic behavior (benign vs malignant). Eighty seven adrenal tumors were investigated by immunocytochemistry (ICC) using monoclonal antibodies against N-cadherin (NCAD), E-cadherin (ECAD), neural cell adhesion molecule (NCAM), and CD44. Western blotting was performed on 30 tumors using the same antibodies. Markers for proliferation (Ki-67) and catecholamine synthesis (tyrosine hydroxylase) were also analyzed in tumors by ICC. NCAD was expressed in 12/27 benign pheochromocytomas (BPCs) (12 familial cases), 8/8 malignant pheochromocytomas (MPCs), 28/30 adrenocortical adenomas, and 9/22 adrenocortical carcinomas. ECAD was expressed in 0/27 BPCs, 0/8 MPCs, 0/30 adrenocortical adenomas, and 2/22 adrenocortical carcinomas. NCAM was expressed in 26/27 BPCs, 7/8 MPCs, 21/30 adrenocortical adenomas, and 17/22 adrenocortical carcinomas. CD44 was expressed in 23/27 BPCs, 6/8 MPCs, 7/30 adrenocortical adenomas, and 4/22 adrenocortical carcinomas. Both cortical and medullary adrenal tumors expressed NCAD, NCAM, and CD44 but were devoid of ECAD. The expression of CD44 and NCAM did not correlate with the malignant potential of tumors. NCAD was upregulated in MPCs, but downregulated in adrenocortical carcinoma. Thus, NCAD appears to be involved in the development of both cortical and medullary adrenal tumors.