Use of ketoconazole in the treatment of Cushing's disease and ectopic ACTH syndrome

How best to monitor the specific side effects of medical treatments of Cushing's disease

The first-line treatment of Cushing's disease is transsphenoidal surgery. Medical treatment of Cushing's disease can be considered in several situations: as a presurgical treatment in patients with severe comorbidities, when surgery fails, or while waiting for the maximal efficacy of radiation techniques. Several modalities of medical treatment are possible, from adrenal-targeting drugs (steroidogenesis inhibitors) to pituitary-targeting drugs (somatostatin receptor ligand pasireotide or the dopamine agonist cabergoline), or even drugs that antagonize the glucocorticoid receptor (mifepristone). Given the morbidities associated with hypercortisolism, and the fact that medical treatment can be delivered on a long-term basis, it is important to obtain eucortisolism and to monitor the drug effectively. The efficacy of these drugs will not be detailed in this review, nor their roles in the therapeutic algorithm of Cushing's disease. This review will rather focus specifically on adverse events associated with these drugs (ketoconazole, levoketoconazole, metyrapone, osilodrostat, pasireotide, cabergoline and mifepristone), and the way in which to monitor and treat them, based on retrospective studies and the most recently published prospective studies.

Adrenally Directed Medical Therapies for Cushing Syndrome

CONTEXT

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Advances in the Medical Treatment of Cushing Disease

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

Current management of Cushing's disease

Cushing's disease (CD) is caused by a pituitary tumour that secretes adrenocorticotropin (ACTH) autonomously, leading to excess cortisol secretion from the adrenal glands. The condition is associated with increased morbidity and mortality that can be mitigated by treatments that result in sustained endocrine remission. Transsphenoidal pituitary surgery (TSS) remains the mainstay of treatment for CD but requires considerable neurosurgical expertise and experience in order to optimize patient outcomes. Up to 90% of patients with microadenomas (tumour below 1 cm in largest diameter) and 65% of patients with macroadenomas (tumour at or above 1 cm in greatest diameter) achieve endocrine remission after TSS by an experienced surgeon. Patients who are not in remission postoperatively or those who relapse may benefit from undergoing a second pituitary operation. Alternatively, radiation therapy to the sella with interim medical therapy, or bilateral adrenalectomy, can be effective as definitive treatments of CD. Medical therapy is currently adjunctive in most patients with CD and is generally prescribed to patients who are about to receive radiation therapy and will be awaiting its salutary effects to occur. Available treatment options include steroidogenesis inhibitors, centrally acting agents and glucocorticoid receptor antagonists. Several novel agents are in clinical trials and may eventually constitute additional treatment options for this serious condition.

Chronic and acute stress monitoring by electrophysiological signals from adrenal gland

We present electrophysiological (EP) signals correlated with cellular cell activities in the adrenal cortex and medulla using an adrenal gland implantable flexible EP probe. With such a probe, we could observe the EP signals from the adrenal cortex and medulla in response to various stress stimuli, such as enhanced hormone activity with adrenocorticotropic hormone, a biomarker for chronic stress response, and an actual stress environment, like a forced swimming test. This technique could be useful to continuously monitor the elevation of cortisol level, a useful indicator of chronic stress that potentially causes various diseases.

Beyond the Dual Paraneoplastic Syndromes of Small-Cell Lung Cancer with ADH and ACTH Secretion: A Case Report with Literature Review and Future Implications

We present a case of small-cell lung cancer (SCLC) with syndrome of inappropriate antidiuretic hormone secretion (SIADH) in which serum sodium gradually normalized with the onset of hypertension, refractory hypokalemia, and chloride-resistant metabolic alkalosis due to ectopic adrenocorticotrophic hormone (ACTH) secretion (EAS). In this case report, we discuss the diagnostic challenges of dual paraneoplastic syndromes with SIADH and EAS, management of SCLC with paraneoplastic endocrinopathies, and their prognostic impact on SCLC. In addition, we discuss neuroendocrine differentiation and ectopic hormone production in relation to intratumoral heterogeneity in SCLC and propose tumor microenvironment and hormonal and metabolic dependence as important determinants of tumor growth and survival.

Preoperative medical treatment in Cushing's syndrome: frequency of use and its impact on postoperative assessment: data from ERCUSYN

BACKGROUND

Surgery is the definitive treatment of Cushing's syndrome (CS) but medications may also be used as a first-line therapy. Whether preoperative medical treatment (PMT) affects postoperative outcome remains controversial.

OBJECTIVE

(1) Evaluate how frequently PMT is given to CS patients across Europe; (2) examine differences in preoperative characteristics of patients who receive PMT and those who undergo primary surgery and (3) determine if PMT influences postoperative outcome in pituitary-dependent CS (PIT-CS).

PATIENTS AND METHODS

1143 CS patients entered into the ERCUSYN database from 57 centers in 26 countries. Sixty-nine percent had PIT-CS, 25% adrenal-dependent CS (ADR-CS), 5% CS from an ectopic source (ECT-CS) and 1% were classified as having CS from other causes (OTH-CS).

RESULTS

Twenty per cent of patients took PMT. ECT-CS and PIT-CS were more likely to receive PMT compared to ADR-CS (P < 0.001). Most commonly used drugs were ketoconazole (62%), metyrapone (16%) and a combination of both (12%). Median (interquartile range) duration of PMT was 109 (98) days. PIT-CS patients treated with PMT had more severe clinical features at diagnosis and poorer quality of life compared to those undergoing primary surgery (SX) (P < 0.05). Within 7 days of surgery, PIT-CS patients treated with PMT were more likely to have normal cortisol (P < 0.01) and a lower remission rate (P < 0.01). Within 6 months of surgery, no differences in morbidity or remission rates were observed between SX and PMT groups.

CONCLUSIONS

PMT may confound the interpretation of immediate postoperative outcome. Follow-up is recommended to definitely evaluate surgical results.

Treatment of Cushing's Syndrome: An Endocrine Society Clinical Practice Guideline

OBJECTIVE

The objective is to formulate clinical practice guidelines for treating Cushing's syndrome.

PARTICIPANTS

Participants include an Endocrine Society-appointed Task Force of experts, a methodologist, and a medical writer. The European Society for Endocrinology co-sponsored the guideline.

EVIDENCE

The Task Force used the Grading of Recommendations, Assessment, Development, and Evaluation system to describe the strength of recommendations and the quality of evidence. The Task Force commissioned three systematic reviews and used the best available evidence from other published systematic reviews and individual studies.

CONSENSUS PROCESS

The Task Force achieved consensus through one group meeting, several conference calls, and numerous e-mail communications. Committees and members of The Endocrine Society and the European Society of Endocrinology reviewed and commented on preliminary drafts of these guidelines.

CONCLUSIONS

Treatment of Cushing's syndrome is essential to reduce mortality and associated comorbidities. Effective treatment includes the normalization of cortisol levels or action. It also includes the normalization of comorbidities via directly treating the cause of Cushing's syndrome and by adjunctive treatments (eg, antihypertensives). Surgical resection of the causal lesion(s) is generally the first-line approach. The choice of second-line treatments, including medication, bilateral adrenalectomy, and radiation therapy (for corticotrope tumors), must be individualized to each patient.

The Treatment of Cushing's Disease

Cushing's disease (CD), or pituitary-dependent Cushing's syndrome, is a severe endocrine disease caused by a corticotroph pituitary tumor and associated with increased morbidity and mortality. The first-line treatment for CD is pituitary surgery, which is followed by disease remission in around 78% and relapse in around 13% of patients during the 10-year period after surgery, so that nearly one third of patients experience in the long-term a failure of surgery and require an additional second-line treatment. Patients with persistent or recurrent CD require additional treatments, including pituitary radiotherapy, adrenal surgery, and/or medical therapy. Pituitary radiotherapy is effective in controlling cortisol excess in a large percentage of patients, but it is associated with a considerable risk of hypopituitarism. Adrenal surgery is followed by a rapid and definitive control of cortisol excess in nearly all patients, but it induces adrenal insufficiency. Medical therapy has recently acquired a more important role compared to the past, due to the recent employment of novel compounds able to control cortisol secretion or action. Currently, medical therapy is used as a presurgical treatment, particularly for severe disease; or as postsurgical treatment, in cases of failure or incomplete surgical tumor resection; or as bridging therapy before, during, and after radiotherapy while waiting for disease control; or, in selected cases, as primary therapy, mainly when surgery is not an option. The adrenal-directed drug ketoconazole is the most commonly used drug, mainly because of its rapid action, whereas the glucocorticoid receptor antagonist, mifepristone, is highly effective in controlling clinical comorbidities, mainly glucose intolerance, thus being a useful treatment for CD when it is associated with diabetes mellitus. Pituitary-directed drugs have the advantage of acting at the site responsible for CD, the pituitary tumor. Among this group of drugs, the dopamine agonist cabergoline and the somatostatin analog pasireotide result in disease remission in a consistent subgroup of patients with CD. Recently, pasireotide has been approved for the treatment of CD when surgery has failed or when surgery is not an option, and mifepristone has been approved for the treatment of Cushing's syndrome when associated with impairment of glucose metabolism in case of the lack of a surgical indication. Recent experience suggests that the combination of different drugs may be able to control cortisol excess in a great majority of patients with CD.

Current approaches to the pharmacological management of Cushing's disease

If treatment of Cushing's disease (CD) by surgery is not successful, medical therapy is often required. Long-term use of metyrapone is limited by hirsutism and hypertension and escape because of increased ACTH levels. Although ketoconazole can normalize cortisol levels in 50%, liver toxicity limits its use. Mitotane, an adrenolytic agent, has had minimal use for benign disease. Etomidate is useful when rapid reduction in cortisol levels is needed. Cabergoline can normalize cortisol levels in CD in about one-third of patients and is well tolerated. Pasireotide can normalize cortisol levels in CD in about 25% but causes worsening of glucose tolerance in most patients. Mifepristone, a blocker of cortisol receptors, improves clinical aspects of CD in most patients but cortisol and ACTH measurements do not reflect clinical activity and adrenal insufficiency, hypokalemia, and endometrial hyperplasia can occur. Combinations of drugs can be tried in patients resistant to monotherapy.

Therapy of endocrine disease: steroidogenesis enzyme inhibitors in Cushing's syndrome

Steroidogenesis enzyme inhibitors are the mainstay of medical therapy in Cushing's syndrome (CS). Ketoconazole (KTZ) and metyrapone are the most commonly used agents. Although there is considerable experience of their use in individual specialist centres, these drugs have not been rigorously tested in prospective clinical trials. Clinicians face uncertainties and concerns with respect to the safety profile of these agents, and best means to monitor effect. We review steroidogenesis inhibitors in the management of CS, including older agents (KTZ, metyrapone, etomidate and mitotane) and those currently under development (LCI699, non-racemic KTZ), and offer a practical approach for their use in clinical practice.

Rapid control of severe neoplastic hypercortisolism with metyrapone and ketoconazole

CONTEXT

Severe Cushing's syndrome elicited by ectopic ACTH syndrome (EAS) or adrenal carcinoma (ACC) can threaten life in the short term. The effectiveness of oral administration of the inhibitors of steroidogenesis ketoconazole and metyrapone in this situation is poorly described.

OBJECTIVE

To report the short-term effectiveness and tolerability of metyrapone and ketoconazole elicited either by EAS or by ACC in patients exhibiting severe hypercortisolism.

DESIGN

Retrospective analysis of data obtained for patients with urinary free cortisol (UFC) level estimated to be fivefold the upper limit of the normal range (ULN).

PATIENTS AND SETTINGS

A total of 14 patients with EAS and eight with ACC treated in two tertiary-care university hospitals.

INTERVENTION

Metyrapone and ketoconazole treatment in combination (along with symptomatic treatments for co-morbidities).

MAIN OUTCOME

Evolution of clinically relevant endpoints (blood pressure, kalaemia and glycaemia) and biological intensity of hypercortisolism 1 week and 1 month after starting steroidogenesis inhibition.

RESULTS

After 1 week of treatment, median UFC fell from 40.0 to 3.2 ULN and from 16.0 to 1.0 ULN in patients with EAS and ACC respectively. Median UFC after 1 month of treatment was 0.5 and 1.0 ULN in patients with EAS and ACC respectively and UFC values were normal in 73 and 86% of patients respectively. Clinical status improved dramatically along with kalaemia, glycaemia and blood pressure, allowing a decrease in the relevant treatments.Side effects were minimal and only two patients (one EAS and one ACC) experienced plasma transaminase elevations necessitating ketoconazole withdrawal.

CONCLUSION

Metyrapone-ketoconazole combination therapy is well tolerated and provides rapid control of endocrine cancer-related life-threatening hypercortisolism.

Treatment of Cushing's disease: a mechanistic update

Cushing's disease (CD) is characterized by an ACTH-producing anterior corticotrope pituitary adenoma. If hypothalamus-pituitary-adrenal (HPA) axis physiology is disrupted, ACTH secretion increases, which in turn stimulates adrenocortical steroidogenesis and cortisol production. Medical treatment plays an important role for patients with persistent disease after surgery, for those in whom surgery is not feasible, or while awaiting effects of radiation. Multiple drugs, with different mechanisms of action and variable efficacy and tolerability for controlling the deleterious effects of chronic glucocorticoid excess, are available. The molecular basis and clinical data for centrally acting drugs, adrenal steroidogenesis inhibitors, and glucocorticoid receptor antagonists are reviewed, as are potential novel molecules and future possible targets for CD treatment. Although progress has been made in the understanding of specific corticotrope adenoma receptor physiology and recent clinical studies have detected improved effects with a combined medical therapy approach, there is a clear need for a more efficacious and better-tolerated medical therapy for patients with CD. A better understanding of the molecular mechanisms in CD and of HPA axis physiology should advance the development of new drugs in the future.

Ketoconazole in Cushing's disease: is it worth a try?

BACKGROUND

The use of ketoconazole has been recently questioned after warnings from the European Medicine Agencies and the Food and Drug Administration due to potential hepatotoxicity. However, ketoconazole is frequently used as a drug to lower circulating cortisol levels. Several pharmacological agents have recently been approved for the treatment of Cushing's disease (CD) despite limited efficacy or significant side effects. Ketoconazole has been used worldwide for more than 30 years in CD, but in the absence of a large-scale study, its efficacy and tolerance are still under debate.

PATIENTS AND METHODS

We conducted a French retrospective multicenter study reviewing data from patients treated by ketoconazole as a single agent for CD, with the aim of clarifying efficacy and tolerance to better determine the benefit/risk balance.

RESULTS

Data from 200 patients were included in this study. At the last follow-up, 49.3% of patients had normal urinary free cortisol (UFC) levels, 25.6% had at least a 50% decrease, and 25.4% had unchanged UFC levels. The median final dose of ketoconazole was 600 mg/d. Forty patients (20%) received ketoconazole as a presurgical treatment; 40% to 50% of these patients showed improvement of hypertension, hypokalemia, and diabetes, and 48.7% had normal UFC before surgery. Overall, 41 patients (20.5%) stopped the treatment due to poor tolerance. Mild (<5N, inferior to 5-fold normal values) and major (>5N, superior to 5-fold normal values) increases in liver enzymes were observed in 13.5% and 2.5% of patients, respectively. No fatal hepatitis was observed.

CONCLUSIONS

Ketoconazole is an effective drug with acceptable side effects. It should be used under close liver enzyme monitoring. Hepatotoxicity is usually mild and resolves after drug withdrawal.

Medical management of persistent and recurrent cushing disease

Recent evidence supports the notion that the incidence of Cushing disease is higher than previously thought. Transphenoidal surgery, in the hands of experienced neurosurgeons, is currently considered the first-line treatment of choice. However, an examination of remission and recurrence rates in long-term follow-up studies reveals that potentially up to 40% to 50% of patients could require additional treatment. If left untreated, the resultant morbidity and mortality are high. Successful clinical management of patients with Cushing disease remains a challenge. The development of new therapeutic agents has been eagerly anticipated. This article discusses the results of currently available and promising new therapeutic agents used to treat this challenging disease.

A reappraisal of the medical therapy with steroidogenesis inhibitors in Cushing's syndrome

OBJECTIVE

To evaluate the outcome of preoperative therapy with ketoconazole (KTZ) and/or metyrapone (MTP) in previously untreated patients with Cushing's syndrome (CS).

DESIGN AND PATIENTS

Sixty-two patients with CS (85% ACTH dependent), treated with steroidogenesis inhibitors prior to surgery between 1983 and 2010, were retrospectively studied. T(0) and t(1) defined baseline and end of preoperative medical treatment.

RESULTS

Outcomes were based upon clinical and biochemical (normal UFC) control of hypercortisolism at t(1) : group CO (controlled) included 20 patients (32%) with eucortisolism and significant clinical improvement; group NC (not controlled) 30 (48%) with persistent hypercortisolism and no control of symptoms; and group PC (partially controlled) 12 patients (19%) who despite eucortisolism had no real clinical improvement. Median duration of treatment was 4 months (range: 1-30·7), and median cumulative dose of KTZ and MTP was 57 g (range: 3·6-240) and 120 g (range: 7·5-1215). CO patients were treated more with KTZ alone than the other groups (P < 0·05). MTP alone was administered more in PC than in CO patients (P < 0·01). No clinical differences were observed between groups at baseline. Systolic blood pressure at t(1) was higher in PC than in NC patients (P < 0·05). Hypertension persisted more in PC patients than in the other groups (P < 0·05) after a median postsurgery follow-up of 108 months (range: 4-276).

CONCLUSIONS

Preoperative administration of KTZ, MTP or both normalized UFC in 52% of patients with CS, but concomitant clinical improvement did not always follow. Larger, multicentre studies are needed to individualize preoperative medical treatment and improve outcome in patients with CS.

Isolated Cushing's syndrome in early infancy due to left adrenal adenoma: an unusual aetiology

Bilateral macronodular adrenocortical disease as a part of McCune Albright Syndrome (MAS) is the most common cause of endogenous Cushing's syndrome (CS) in infancy. Adrenocortical tumors causing CS in infancy are extremely rare. We report the case of a girl with CS who presented at age 4 months with obesity and growth retardation. Her 8 am paired cortisol and adrenocorticotropic hormone levels were 49.3 µg/dL and <1 pg/mL, respectively with non-suppressed serum cortisol (41 µg/dL) on high-dose dexamethasone suppression test. Abdominal computed tomography scan demonstrated a 5.3x4.8x3.7 cm homogenous left adrenal mass with distinct borders. Laparotomy following pre-operative stabilization with ketoconazole 200 mg/day, revealed a 7.5x5x4 cm lobulated left adrenal mass with intact capsule and weighing 115 grams. Histopathology showed small round adrenal tumor cells with increased nucleo-cytoplasmic ratio and prominent nucleoli. The cells were separated by fibrous septae without any evidence of vascular or capsular invasion- findings consistent with adrenal adenoma. On the 8th post-operative day, after withholding hydrocortisone supplementation, the 8 am cortisol level was <1 µg/dL, suggestive of biochemical remission of CS. The patient improved clinically with a 7.5 kg weight loss over the next 3.5 months. This is perhaps the youngest ever reported infant with CS due to adrenal adenoma. Lack of clinical and biochemical evidence of hyperandrogenism as well as the benign histology in spite of the large tumor size (>7 cm diameter; 115 g) are some of the unique features of our patient.

Cushing's Syndrome due to Ectopic ACTH from Bronchial Carcinoid: A Case Report and Review

Despite advances in analytic and imaging techniques, the syndrome of ectopic adrenocorticotrophic hormone (ACTH) secretion from a tumour resulting in Cushing's syndrome continues to pose difficult diagnostic and therapeutic challenges. Dynamic testing may be equivocal and radiology indeterminate. We report a patient presenting with Cushing's syndrome associated with ectopic ACTH secretion from a bronchial carcinoid whose management presented diagnostic and therapeutic challenges.

Case report: a rare cause of metabolic alkalosis

A case of a 66-year-old white man with recent onset of oedema, hypertension, metabolic alkalosis and profound hypokalaemia is described. The initial laboratorial workup showed that urinary chloride concentration and potassium excretion were increased, suggesting a state of hyperaldosteronism. Nonetheless, renin activity was low and aldosterone levels were normal. The metabolic alkalosis seen in this case was due to a rare cause, the ectopic adrenocorticotropic hormone syndrome. A literature review in the subject is presented.

Management of Cushing disease

Cushing disease is caused by a corticotroph tumor of the pituitary gland. Patients with Cushing disease are usually treated with transsphenoidal surgery, as this approach leads to remission in 70-90% of cases and is associated with low morbidity when performed by experienced pituitary gland surgeons. Nonetheless, among patients in postoperative remission, the risk of recurrence of Cushing disease could reach 20-25% at 10 years after surgery. Patients with persistent or recurrent Cushing disease might, therefore, benefit from a second pituitary operation (which leads to remission in 50-70% of cases), radiation therapy to the pituitary gland or bilateral adrenalectomy. Remission after radiation therapy occurs in ∼85% of patients with Cushing disease after a considerable latency period. Interim medical therapy is generally advisable after patients receive radiation therapy because of the long latency period. Bilateral adrenalectomy might be considered in patients who do not improve following transsphenoidal surgery, particularly patients who are very ill and require rapid control of hypercortisolism, or those wishing to avoid the risk of hypopituitarism associated with radiation therapy. Adrenalectomized patients require lifelong adrenal hormone replacement and are at risk of Nelson syndrome. The development of medical therapies with improved efficacy might influence the management of this challenging condition.

Ketoconazole revisited: a preoperative or postoperative treatment in Cushing's disease

CONTEXT

Although transsphenoidal surgery remains the first-line treatment in Cushing's disease (CD), recurrence is observed in about 20% of cases. Adjunctive treatments each have specific drawbacks. Despite its inhibitory effects on steroidogenesis, the antifungal drug ketoconazole was only evaluated in series with few patients and/or short-term follow-up.

OBJECTIVE

Analysis of long-term hormonal effects and tolerance of ketoconazole in CD.

DESIGN

A total of 38 patients were retrospectively studied with a mean follow-up of 23 months (6-72).

SETTING

All patients were treated at the same Department of Endocrinology in Marseille, France.

PATIENTS

The 38 patients with CD, of whom 17 had previous transsphenoidal surgery.

INTERVENTION

Ketoconazole was begun at 200-400 mg/day and titrated up to 1200 mg/day until biochemical remission.

MAIN OUTCOME MEASURES

Patients were considered controlled if 24-h urinary free cortisol was normalized.

RESULTS

Five patients stopped ketoconazole during the first week because of clinical or biological intolerance. On an intention to treat basis, 45% of the patients were controlled as were 51% of those treated long term. Initial hormonal levels were not statistically different between patients controlled or uncontrolled. Ketoconazole was similarly efficacious as a primary or postoperative treatment. Among 15 patients without visible adenoma at initial evaluation, subsequent follow-up allowed identification of the lesion in five cases. No adrenal insufficiency was observed. Adverse effects were rare in patients treated long term.

CONCLUSIONS

Ketoconazole is a safe and efficacious treatment in CD, particularly in patients for whom surgery is contraindicated, or delayed because of the absence of image of adenoma on magnetic resonance imaging.

Adrenocorticotropin-secreting pancreatoblastoma

We present a 3-year-old child with Cushing's syndrome due to an ACTH-secreting metastatic pancreatoblastoma. This malignancy is a rare cause of Cushing's syndrome, particularly at pediatric age. We describe her course including the use of ketoconazole to alleviate hypercortisolemia.

A case of recurrent non-small-cell lung carcinoma and paraneoplastic Cushing's syndrome

Secretion of ectopic adrenocorticotropic hormone (ACTH) with consequently Cushing's syndrome is a rare paraneoplastic phenomenon. It has been described in a variety of malignancies, like bronchial carcinoids, small-cell lung carcinoma, thymoma, pancreatic carcinoma and other. In many cases of suspected ectopic ACTH secretion, it is difficult to histologically or cytochemically confirm the diagnosis. We present a 63-year-old woman with a recurrent poorly differentiated squamous cell lung carcinoma with clinical and biochemical features consistent with ectopic Cushing's syndrome. Immunocytochemical staining confirmed the secretion of ACTH by tumour cells.

Pituitary surgery and postoperative management in Cushing's disease

Transsphenoidal pituitary surgery is the therapy for most Cushing's disease patients. This article describes the surgical technique, efficacy, perioperative management, and complications associated with this procedure. Numerous biochemical tests of cortisol status have been studied for the evaluation of the postoperative patient. Factors that predict postoperative remission and future relapse of Cushing's disease are addressed. Secondary interventions for persistent or recurrent disease include repeat transsphenoidal resection, pituitary radiation, medical therapy, and bilateral adrenalectomy

PPAR-gamma in Cushing's disease

The majority of pituitary tumors that cause Cushing's disease are small (<1 cm diameter), and most disease morbidity is due to the effects of elevated, non-suppressible, ACTH levels that these tumors secrete. Tumor-derived ACTH leads to adrenal-derived steroid hypersecretion and results in many disabling and sometimes life-threatening symptoms including abnormal fat deposition, skin thinning, psychological disturbances, hypertension, diabetes, osteoporosis and muscle weakness. Cushing's disease is associated with high morbidity and ultimately mortality. In experienced specialized centers, 70% of corticotroph microadenomas can be successfully resected by transsphenoidal pituitary surgery. However, surgical "cure" rates for larger ACTH-secreting pituitary tumors are achieved in only 30% of cases, and recent reports highlight a significant recurrence rate after longer term follow-up even in smaller tumors. Post-surgical persistence of ACTH hypersecretion may require pituitary-directed radiation, but this treatment may take some time to be effective, and like extensive surgical pituitary tumor resection, ultimately leads to partial- or total hypopituitarism in approximately 80% of cases. Although hypercortisolism may be completely resolved by adrenalectomy, this procedure does not suppress, and may act as a stimulus to pituitary tumor growth, and is associated with other co-morbidity. Although some currently available drug-based treatments for Cushing's disease effectively control hypercortisolism, their drawback has been that they do not impact on pituitary tumor growth. Recent studies have identified the potential utility of peroxisome-proliferator activating receptor-gamma (PPAR-gamma) novel ligands in in vitro, and in vivo Cushing's disease models, and have paved the way for early clinical studies to develop novel therapeutic approaches in Cushing's disease.

Cortisol and the renal handling of electrolytes: role in glucocorticoid-induced hypertension and bone disease

Hypertension and osteoporosis are characteristic clinical features in patients with Cushing's syndrome or in those on glucocorticoid (GC) treatment. These two distinct complications of GC excess share one common denominator: an abnormal handling of cations, sodium (Na(+)) and calcium (Ca(2+)), either primarily or in part by the kidney tubule. The principal mechanism of GC-induced hypertension is overstimulation of the non-selective mineralocorticoid receptor (MR), resulting in renal Na(+) retention, volume expansion and finally to an increase in blood pressure. In mineralocorticoid target organs, such as the kidney, the MR is protected from GC occupation by the enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2), a gate-keeping enzyme, which converts cortisol to receptor-inactive cortisone. This enzyme allows aldosterone to be the physiological agonist of the MR despite significantly higher circulating levels of cortisol. Kinetic properties of 11betaHSD2 suggest that saturability of this enzyme can already be achieved at high-normal physiological plasma cortisol levels, thereby leading to ovestimualtion of the MR by cortisol in states of GC excess. The mechanisms of GC action on bone turnover are more complex. GCs increase bone resorption, inhibit bone formation and have an indirect action on bone by decreasing intestinal Ca(2+) absorption, but also inducing a sustained renal Ca(2+) excretion. The latter appears to be mediated through stimulation of the MR by GC. The prevention and treatment of GC-induced hypertension and osteoporosis include the use of the minimal effective dose of GC, some general measures, and the use of some specific drugs. Modulation of renal Na(+) and Ca(2+) excretion with some, but not all, diuretics represents an important specific (for hypertension) or supportive (for bone disease) therapeutic intervention.

The medical management of Cushing's syndrome

Cushing's syndrome results from prolonged exposure to excessive circulating glucocorticosteroids, and is associated with significant morbidity and mortality. While the treatment of choice in most patients is surgical, the metabolic consequences of the syndrome, including increased tissue fragility, poor wound healing, hypertension, and diabetes mellitus, increase the risks of such surgery. The hypercortisolemia and its sequelae can be efficiently reversed using medical therapy, either as a temporary measure prior to definitive treatment, or longer term in more difficult cases. Drug treatment has been targeted at the hypothalamic/pituitary level, the adrenal glands, and also at the glucocorticoid receptor level. In this review we discuss the pharmacotherapeutic agents that have been used in Cushing's syndrome, and their efficacy, the monitoring of treatment, and potential therapies that may prove useful in the future in this complex endocrinological disorder.

Pituitary tumor diagnosis and treatment

Over the past few years, significant contributions have been made to the understanding, diagnosis, and treatment of pituitary tumors. This article reviews recent advances in the areas of biology, diagnostic imaging, medical diagnosis and treatment, surgical results and technique, and adjuvant therapy in the form of radiotherapy and radiosurgery. Of particular note are the roles of endoscopy, intraoperative magnetic resonance imaging, radiosurgery, and radiation for nonfunction tumors, the diagnosis of Cushing's disease, the management of "incidentalomas," and new medication therapies.

Cushing syndrome due to ectopic adrenocorticotropic hormone secretion

Cushing syndrome (CS) caused by ectopic adrenocorticotropic hormone (ACTH) production (EA) poses major challenges diagnostically by mimicking the pituitary-dependent form of CS and therapeutically by producing severe, life-threatening hypercortisolemia. This retrospective follow-up study describes the clinical characteristics and course of EA in a large referral center. Computer-based cross-index codes for EA, CS, and bilateral adrenalectomy were used to identify patients treated at the Mayo Clinic between 1956 and 1998. EA was confirmed in 106 patients. Gender distribution showed a slight female predominance (61:45). Bronchial carcinoid was the most frequent cause of EA (25%), followed by islet cell cancer (16%), small-cell lung carcinoma (11%), medullary thyroid cancer (8%), disseminated neuroendocrine tumor of unknown primary source (7%), thymic carcinoid (5%), pheochromocytoma (3%), disseminated gastrointestinal carcinoid (1%), and other tumors (8%). No tumor was found in 16% of patients. Altogether, 28 patients were managed medically, and the others underwent curative tumor resection (13 patients) or bilateral adrenalectomy (65 patients). Surgically treated patients had longer survival, but this was most likely affected by treatment bias. The diagnoses of CS and ACTH-secreting neoplasm were usually concurrent, although, there were remarkable cases in which the two conditions were diagnosed several years apart. Curative resection of the tumor producing EA was possible in a small proportion of patients (12%). When curative resection is not possible, patients who are reasonable surgical candidates are likely to benefit from adrenalectomy. Additional experience with bilateral laparoscopic adrenalectomy should increase the number of patients who benefit from adrenal-directed surgery.

Fatal liver failure due to ketoconazole treatment of a girl with Cushing's syndrome

A patient is reported who developed fatal liver failure on ketoconazole treatment for Cushing's syndrome. It is recommended that metyrapone be used when hypercortisolism has to be controlled as a temporary measure in childhood and adolescence.

S, Leite V, Canadas V. Tratamento medicamentoso dos tumores hipofisários. parte II: adenomas secretores de ACTH, TSH e adenomas clinicamente não-funcionantes

Este artigo revisa o potencial papel do tratamento medicamentoso para os adenomas hipofisários secretores de ACTH, TSH e aqueles clinicamente não-funcionantes (ACNF), Metirapona, mitotano e cetoconazol (preferível por causar menos efeitos colaterais) são as drogas mais eficazes no controle do hipercortisolismo, mas nenhuma delas supera a eficácia da cirurgia transesfenoidal (TSA). O tratamento medicamentoso da doença de Cushing está, portanto, melhor indicado para pacientes aguardando o efeito pleno da radioterapia ou, como alternativa para esta última, em casos de hipercortisolismo persistente após TSA, e para pacientes com rejeição ou limitações clínicas para a cirurgia. Outra indicação potencial seria em idosos com microadenomas ou pequenos macroadenomas, ou em casos associados a sela vazia. No que se refere aos adenomas secretores de TSH, os análogos somatostatínicos (SRIFa) proporcionam normalização dos hormônios tiroideanos em até 95% dos casos. Assim, eles podem se mostrar úteis em casos de insucesso da cirurgia ou como terapia primária de casos selecionados. Ocasionalmente, agonistas dopaminérgicos (DA), sobretudo a cabergolina, também podem ser eficazes. Em contraste, DA e SRIFa raramente induzem uma significante redução das dimensões dos ACNFs. Por isso, em pacientes com tais tumores, essas drogas devem ser principalmente consideradas diante de contra-indicações ou limitações clínicas para a cirurgia ou quando a cirurgia e a radioterapia tenham sido mal-sucedidas.

High-dose dexamethasone suppression testing versus inferior petrosal sinus sampling in the differential diagnosis of adrenocorticotropin-dependent Cushing's syndrome: a decision analysis

Differentiation of adrenocorticotropin (ACTH)-dependent Cushing's syndrome between Cushing's disease and the occult ectopic ACTH syndrome is difficult. Simultaneous bilateral inferior petrosal sinus sampling (IPSS) for ACTH levels in response to corticotropin-releasing hormone has high diagnostic accuracy, but its cost-effectiveness has not been analyzed. In this study, decision analysis was used to compare two diagnostic strategies: IPSS versus high-dose dexamethasone suppression (HDD) followed by IPSS in those with a negative HDD test. Sensitivity analyses were performed for all variables. The authors found that at 100% accuracy, IPSS has an incremental cost-effectiveness ratio of $1,000,000 per life saved. Incremental cost, incremental effectiveness, and incremental cost-effectiveness are sensitive to the pretest probability of Cushing's disease, test characteristics, and test costs. As the pretest probability of Cushing's disease decreases, cost per life saved also decreases to less than 85%, the HDD strategy saves more lives and costs less. When the HDD test has a 83% sensitivity rate and a 100% specificity rate, the two strategy remains less expensive. The IPSS strategy saves lives whenever HDD specificity is less than 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Therapy of Cushing's syndrome with steroid biosynthesis inhibitors

Several substances with different inhibitory effects on adrenal steroid biosynthesis were investigated in patients with Cushing's syndrome. It has been shown that trilostane, a 3 beta-hydroxysteroid-dehydrogenase inhibitor, is not potent enough to block cortisol biosynthesis in patients with hypercortisolism. Aminoglutethimide inhibits side chain cleavage of cortisol synthesis, but it has been demonstrated that the blocking effect on cortisol secretion is not strong enough to normalize urinary cortisol excretion in patients with Cushing's disease. For metyrapone, an inhibitor of adrenal 11 beta-hydroxylase, promising results were reported for the treatment of Cushing's syndrome. However, the drug has several side effects and depending on the definition of the desired reduction of cortisol secretion a true remission was only found in a minority of patients. The antifungal drug ketoconazole in vitro predominantly blocks 17,20-desmolase (IC50 1 microM) and to a lesser extent 17 alpha-hydroxylase (IC50 10 microM) and 11 beta-hydroxylase (IC50 15-40 microM). Therefore, ketoconazole in vivo most potently suppresses androgen secretion and only to a lesser extent cortisol biosynthesis. Several therapeutic trials with ketoconazole treatment in patients with pituitary Cushing's disease showed various remission rates between 30 and 90%. In contrast, in almost all patients with benign, primary adrenal Cushing's syndrome cortisol levels were normalized. In patients with ectopic ACTH syndrome ketoconazole was effective in about 50% of all reported cases, while cortisol hypersecretion due to adrenocortical carcinoma was only rarely inhibited by ketoconazole. The main side effect of ketoconazole treatment was liver toxicity which occurred in 12% of all treated patients. In contrast to ketoconazole, the narcotic drug etomidate shows a strong inhibitory effect on 11 beta-hydroxylase (IC50 0.03-0.15 microM) but only a weak inhibition of 17,20 desmolase (IC50 380 microM). This correlates with in vivo studies where even low, non-hypnotic doses of etomidate induced a pronounced fall in serum cortisol levels in normals and in patients with Cushing's syndrome. However, its clinical use is limited by its mandatory intravenous application and its sedative effects. In conclusion, ketoconazole remains the only available steroid-inhibitory drug for a therapeutic trial in patients with Cushing's syndrome who cannot be treated definitively by surgery.

[Value of ketoconazole in the treatment of Cushing disease]

Ketoconazole has been successfully used in short-term treatment of Cushing's syndrome. We treated 4 patients who had Cushing's disease with ketoconazole administered during 5 to 18 months. Two of them are still controlled after 15 months of treatment and 7 months after treatment was withdrawn. In the other two patients, treatment was ineffective primarily and after 5 months. Our data confirm the usefulness of ketoconazole in the treatment of Cushing's disease, but they also show that primary resistance and tachyphylaxis in long-term treatment may occur, as previously reported.

Ketoconazole treatment in Cushing's syndrome: experience in 34 patients

OBJECTIVE

Ketoconazole treatment of Cushing's syndrome has been reported in single cases and a few small groups of 5-8 patients. We report our experience in 34 patients.

DESIGN

Clinical study, with pretreatment and post-treatment evaluations.

PATIENTS

Out of 67 patients with Cushing's syndrome admitted during the last 6 years, 34 (28 females/six males; age range 14-67 years) received ketoconazole as a palliative treatment due to severe clinical conditions or management of the disease while awaiting results of definitive therapy.

MEASUREMENTS

Urinary cortisol, plasma cortisol and ACTH, and routine chemistry were measured every week for 4 weeks, and then once a month.

RESULTS

Comparing the last values (mean +/- SEM) during treatment with baseline, urinary cortisol decreased from 1296 +/- 176 to 270 +/- 69 nmol/d (n = 34; P less than 0.001); plasma cortisol decreased from 672 +/- 31 to 549 +/- 35 nmol/l (n = 34; P less than 0.001). For patients with pituitary-dependent Cushing's syndrome, urinary cortisol decreased from 1073 +/- 126 to 200 +/- 21 nmol/d (n = 28; P less than 0.001) while plasma ACTH changed from 12.5 +/- 1.3 to 11.3 +/- 0.8 pmol/l (n = 26; not significant). Twelve patients were treated for more than 6 months, and those with pituitary-dependent disease all received pituitary radiation therapy, except the two who eventually escaped pharmacological control. One additional patient with adrenal carcinoma and one with ectopic ACTH syndrome showed lack of control of urinary cortisol levels. Ketoconazole was withdrawn within the first week in two patients for allergic reaction and acute liver toxicity. Other side-effects included: asymptomatic liver function abnormalities in three patients; gastrointestinal symptoms in four; worsening of gynaecomastia in one. Rapid clinical improvement was observed together with the normalization of urinary cortisol levels, with regression of symptoms such as diabetes mellitus, hypertension, hypokalaemia, and restoration of well being.

CONCLUSIONS

These data confirm that ketoconazole is valuable in the management of hypercortisolism, provided that patients are closely watched to exclude those who may develop liver toxicity and to prevent the occurrence of adrenal insufficiency.