Management of recurrent and refractory Cushing disease

Enhanced EPR effects by tumour stromal cell mimicking nanoplatform on invasive pituitary adenoma

Rapid advances in nanomedicine have enabled potential applications in cancer therapy. The enhanced permeability and retention (EPR) effect is the primary rationale for the passive targeting of nanoparticles in oncology. However, growing evidence indicates that the accumulation of nanomaterials via the EPR effect could be more efficient. Inspired by our clinical observation of the Gap Junction connecpion between folliculostellate cells and pituitary adenoma cells, we designed a novel drug delivery system that targets tumours by coating folliculostellate cell (FS) membranes onto PLGA nanoparticles (NPs). The resulting FSNPs, inheriting membrane proteins from the folliculostellate cell membrane, significantly enhanced the EPR effect compared to nanoparticles without cancer cell membranes. We further demonstrated that mitotane encapsulation improved the therapeutic efficacy of mitotane in both heterotopic and orthotopic pituitary adenoma models. Owing to its significant efficacy, our FS cell membrane-coated nanoplatforms has the potential to be translated into clinical applications for the treatment of invasive pituitary adenoma.

Current and Emerging Pharmacological Therapies for Cushing's Disease

Cushing's Disease (CD), hypercortisolism due to pituitary ACTH secreting neuroendocrine neoplasm, is associated with increased morbidity and, if untreated, mortality in about half of the affected individuals. Consequently, the timely initiation of effective treatment is mandatory. Neurosurgery is the first line and the only potentially curative treatment; however, 30% of patients will have persistent disease post-surgery. Furthermore, a small percentage of those initially controlled will develop hypercortisolism during long-term follow- up. Therefore, patients with persistent or recurrent disease, as well as those considered non-eligible for surgery, will need a second-line therapeutic approach, i.e., pharmacotherapy. Radiation therapy is reserved as a third-line therapeutic option due to its slower onset of action and its unfavorable profile regarding complications. During the past few years, the understanding of molecular mechanisms implicated in the physiology of the hypothalamus-pituitary-adrenal axis has evolved, and new therapeutic targets for CD have emerged. In the present review, currently available treatments, compounds currently tested in ongoing clinical trials, and interesting, potentially new targets emerging from unraveling molecular mechanisms involved in the pathophysiology of Cushing's disease are discussed.

Recurrent Cushing Disease: An Extensive Review on Pros and Cons of Different Therapeutic Approaches

OBJECTIVE

Recurrent Cushing disease (CD) is characterized by the reappearance of clinical and hormonal aspects of hypercortisolism that occur more than 6 months after an initial post-treatment remission.

METHODS

We performed a systematic review and meta-analysis to synthesize the evidence about remission and complication rates after transsphenoidal surgery (TSS) radiotherapy (RT) and medical therapy (MT) in recurrent CD patients. A quantitative systematic review was performed. Article selection was performed by searching MEDLINE (using PubMed), and Cochrane electronic bibliographic databases through 2020.

RESULTS

We noted 61 articles described therapeutic management of recurrent CD patients with representative outcome. A total of 723 patients received different therapeutic modality for their recurrent CD. The remission rates were 0.65 (95% confidence interval [CI] 0.60-0.70), 0.57 (95% CI 0.51-0.63), and 0.75 (95% CI 0.60-0.86) in the TSS, RT, and MT subgroups, respectively. The total remission rate after therapeutic approaches on recurrent CD patients was 0.64 (95% CI 0.60-0.68). A test for subgroup differences revealed there was a statistically significant difference between different subgroups (P = 0.01). The post hoc test showed that in comparison with RT, TSS (P = 0.0344) and MT (P = 0.0149) had a higher rate of remission. However, there was no statistically significant difference between separate therapeutic modalities in terms of complications including diabetes insipidus (P = 1.0) and hypopituitarism (P = 0.28).

CONCLUSIONS

Compared MT and TSS, RT has a statistically lower rate of remission. Although there is robust superiority of surgery over RT, interpretation of MT data must considered with caution due to the small number of included cases and wide CI range.

Radiation Therapy for Recurrent or Residual Pituitary Macroadenoma Invading Extrasellar Structures

PURPOSE

This study aimed to evaluate the efficacy of radiation therapy (RT) for recurrent or residual pituitary macroadenoma (PMA) invading extrasellar regions.

MATERIALS AND METHODS

Patients from 2000 to 2020 who received RT with conventional fractionation for recurrent or residual PMA were included. The patients were divided according to the type of tumor [functioning (fx) or non-fx] and the aim of RT (salvage RT alone, immediate postoperative RT, delayed postoperative RT). Local and biochemical failure-free rates (FFR) were calculated using the Kaplan-Meier method.

RESULTS

With a median follow up of 82 months (IQR; 42-132 months), 36 patients treated with conventional RT (total 45-54 Gy in 1.8 or 2 Gy per fraction) for recurrent or residual PMA were analyzed. The 10-year local FFRs after RT for non-fx and fx tumor were 100% and 74.4%, respectively (p=0.047). In the immediate postoperative RT group, the 10-year local FFR was 100%, which was higher than the 90% FFR for salvage RT alone or 80% FFR for the delayed postoperative RT group (overall p=0.043, immediate vs. salvage; p=0.312, immediate vs. delayed; p=0.072). The local FFR was compared according to size of tumor with a cut-off value of 4 cm, and there was no significant difference (10-year local FFR 100% vs. 84.7% for >4 cm vs. <4 cm, p=0.320). The extents of extrasellar region invasion were not predictive of local failure after RT. We found no grade ≥3 acute toxicities or newly developed visual impairments as a late toxicity of RT.

CONCLUSION

Conventional RT is safe and effective for the local control of recurrent or residual PMA. Our data suggest that immediate postoperative RT can be beneficial in recurrent or residual PMA, although further studies to evaluate risk factors of treatment failure in terms of treatment and disease characteristics are required.

Pituitary Adenomas: Classification, Clinical Evaluation and Management

Pituitary adenomas are one of the most common brain tumors. They represent approximately 18% of all intracranial, and around 95% of sellar neoplasms. In recent years, our understanding of the pathophysiology and the behavior of these lesions has led to better control and higher curative rates. The treatment decision is largely dependent on type of the adenoma, clinical presentation, and the size of the lesion. In addition, incidental pituitary lesions add uncertainty in the decision-making process, especially for pituitary adenomas that can be medically managed. When surgery is indicated, the endoscopic endonasal transsphenoidal approach is the technique of choice, but open standard craniotomy approaches can also be the option in selected cases. The following chapter will review the classification, clinical presentation, pathophysiology, diagnostic work-up, selection of surgical approach, and treatment complications in pituitary adenomas.

Early versus late Gamma Knife radiosurgery for Cushing's disease after prior resection: results of an international, multicenter study

OBJECTIVE

The optimal time to perform stereotactic radiosurgery after incomplete resection of adrenocorticotropic hormone (ACTH)-producing pituitary adenoma in patients with Cushing's disease (CD) remains unclear. In patients with persistent CD after resection of ACTH-producing pituitary adenoma, the authors evaluated the association of the interval between resection and Gamma Knife radiosurgery (GKRS) with outcomes.

METHODS

Pooled data from 10 institutions participating in the International Radiosurgery Research Foundation were used in this study.

RESULTS

Data from 255 patients with a mean follow-up of 65.59 ± 49.01 months (mean ± SD) were analyzed. Seventy-seven patients (30%) underwent GKRS within 3 months; 46 (18%) from 4 to 6 months; 34 (13%) from 7 to 12 months; and 98 (38%) at > 12 months after the resection. Actuarial endocrine remission rates were higher in patients who underwent GKRS ≤ 3 months than when treatment was > 3 months after the resection (78% and 65%, respectively; p = 0.017). Endocrine remission rates were lower in patients who underwent GKRS at > 12 months versus ≤ 12 months after the resection (57% vs 76%, respectively; p = 0.006). In multivariate Cox regression analyses adjusted for clinical and treatment characteristics, early GKRS was associated with increased probability of endocrine remission (hazard ratio [HR] 1.518, 95% CI 1.039-2.218; p = 0.031), whereas late GKRS (HR 0.641, 95% CI 0.448-0.919; p = 0.015) was associated with reduced probability of endocrine remission. The incidence of some degree of new pituitary deficiency (p = 0.922), new visual deficits (p = 0.740), and other cranial nerve deficits (p = 0.610) was not significantly related to time from resection to GKRS.

CONCLUSIONS

Early GKRS is associated with an improved endocrine remission rate, whereas later GKRS is associated with a lower rate of endocrine remission after pituitary adenoma resection. Early GKRS should be considered for patients with CD after incomplete pituitary adenoma resection.

Pasireotide-induced hyperglycemia in a patient with Cushing's disease: Potential use of sodium-glucose cotransporter 2 inhibitor and glucagon-like peptide-1 receptor agonist for treatment

Pasireotide improves hypercortisolemia and induces hyperglycemia via somatostatin receptor type-5 stimulation. GLP-1RA and SGLT2 inhibitor potentially help regulate hyperglycemia in patients with Cushing's disease, especially after pasireotide administration.

Effect of repeated transsphenoidal surgery in recurrent or residual pituitary adenomas: A systematic review and meta-analysis

Background:

Recurrent or residual pituitary adenomas previously treated by transsphenoidal surgery are not uncommon. There are no strongly established guidelines to perform treatment of such cases. The objective of this study is to elucidate the effect of transsphenoidal reoperation in residual or recurrent pituitary adenomas.

Methods:

We made a systematic review of the literature to elucidate this effect through electronic search in MEDLINE/PubMed and Cochrane Central database. PRISMA statement was used as a basis for this systematic review and analysis of the risk of bias was made according to the Grading of Recommendations, Assessment, Development and Evaluation recommendations.

Results:

In this review, fifteen studies were finally pooled analyzed. Although remission rates (RRs) and follow-up periods varied widely, from 149 patients with growth hormone-secreting tumors the mean RR was 44.5%, from 273 patients with adrenocorticotropic hormone-secreting tumors the mean RR was 55.5% and among 173 patients with nonsecreting tumors, RR was 76.1%. There was significant higher RR in nonsecreting tumors. Mean follow-up was 32.1 months. No difference was found between microscopic and endoscopic techniques.

Conclusions:

A second transsphenoidal surgery is accompanied by a chance of remission in approximately half of cases with secreting tumors. In nonsecreting ones, success is higher.

Dilated Cardiomyopathy Revealing Cushing Disease: A Case Report and Literature Review

Cardiovascular impairments are frequent in Cushing's syndrome and the hypercortisolism can result in cardiac structural and functional changes that lead in rare cases to dilated cardiomyopathy (DCM). Such cardiac impairment may be reversible in response to a eucortisolaemic state.A 43-year-old man with a medical past of hypertension and history of smoking presented to the emergency department with global heart failure. Coronary angiography showed a significant stenosis of a marginal branch and cardiac MRI revealed a nonischemic DCM. The left ventricular ejection fraction (LVEF) was estimated as 28% to 30%. Clinicobiological features and pituitary imaging pointed toward Cushing's disease and administration of adrenolytic drugs (metyrapone and ketoconazole) was initiated. Despite the normalization of cortisol which had been achieved 2 months later, the patient presented an acute heart failure. A massive mitral regurgitation secondary to posterior papillary muscle rupture was diagnosed as a complication of the occlusion of the marginal branch. After 6 months of optimal pharmacological treatment for systolic heart failure, as well as treatment with inhibitors of steroidogenesis, there was no improvement of LVEF. The percutaneous mitral valve was therefore repaired and a defibrillator implanted. The severity of heart failure contraindicated pituitary surgery and the patient was instead treated by stereotaxic radiotherapy.This is the first case reporting a Cushing's syndrome DCM without improvement of LVEF despite normalization of serum cortisol levels.

Update on the management of recurrent Cushing's disease

After transsphenoidal surgery, Cushing's disease (CD) shows excellent long-term remission rates, but it may recur and pose a therapeutic challenge. Findings in recent published reports on the treatment of recurrent adrenocorticotropic hormone (ACTH)-secreting tumors suggest that repeat resection, radiation-based therapies such as Gamma Knife surgery and proton-beam radiosurgery, pharmacotherapy, and bilateral adrenalectomy all have important roles in the treatment of recurrent CD. Each of these interventions has inherent risks and benefits that should be presented to the patient during counseling on retreatment options. Radiation-based therapies increasingly appear to have efficacies similar to those of repeat resection in achieving biochemical remission and tumor control. In addition, an expanding retinue of medication-based therapies, several of which are currently being evaluated in clinical trials, has shown some promise as tertiary adjunctive therapies. Lastly, bilateral adrenalectomy may offer durable control of refractory recurrent CD. An increasing number of published studies with long-term patient outcomes highlight the evolving treatment patterns in the management of recurrent CD.

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.

Up-to 5-year efficacy of pasireotide in a patient with Cushing's disease and pre-existing diabetes: literature review and clinical practice considerations

PURPOSE

Pasireotide is a multi-receptor-targeted somatostatin analogue approved in the EU and in the US for the treatment of adults with Cushing's disease (CD). Pasireotide has a safety profile similar to other somatostatin analogues with the exception of hyperglycemia. In this report and literature review, the current understanding of predicting a positive treatment response to pasireotide in CD and the management of diabetes mellitus (DM) during pasireotide treatment are discussed and analyzed.

CASE PRESENTATION

We report a case of a 55-year-old woman with CD and DM who benefitted from long-term pasireotide. The patient, who was enrolled in a phase III trial of the drug, showed early clinical improvements with pasireotide [900 μg subcutaneously twice daily (bid)] but was classified as a non-responder as urinary free cortisol (UFC) levels, were not normalized. Continuation of pasireotide for 12 months at an increased dose (1,200 μg bid) normalized UFC levels and restored cortisol rhythm. The initial deterioration in her blood glucose was managed with insulin and metformin; however, after 12 months' treatment with pasireotide her DM was well controlled with oral hypoglycemic agents. Five years later, the patient is still receiving pasireotide (300 μg bid) with no loss of clinical or biochemical efficacy and with continued glycemic control.

CONCLUSIONS

This case presentation indicates that uncontrolled UFC levels during the first few months of pasireotide treatment as well as worsening of glycemic control in patients with CD and DM are not always predictive of the efficacy and tolerability and appears to support the long-term continuation of pasireotide.

Approach to the postoperative patient with Cushing's disease

INTRODUCTION

Cushing's disease is a neuroendocrine disorder marked by hypercortisolemia secondary to overproduction of ACTH by a corticotropic pituitary adenoma. Due to the diverse and deleterious effects of hypercortisolemia including diabetes mellitus, hypertension, and cardiovascular disease, prompt and accurate diagnosis followed by surgical resection of the responsible corticotropic adenoma is critical.

METHODS

In the following review, we present a focused synopsis of recently published data and management strategies for the post-operative Cushing's disease patient with a particular focus on studies examining perioperative complications, establishment of biochemical remission, factors associated with disease remission, and predictors of recurrence.

CONCLUSIONS

Although no standard definition of remission exists, we suggest measurement of serum cortisol level on the morning of postoperative day 1 given the preponderance of evidence in the published literature suggesting its association with long-term remission and relatively low rates of recurrence. Nevertheless, all patients should be counseled that recurrence can occur in a delayed fashion and that annual endocrine testing should be utilized to track and confirm disease status.

Therapeutic outcomes in patients undergoing surgery after diagnosis of Cushing's disease: A single-center study

This study aimed to investigate early and late outcomes of patients who underwent neurosurgical procedures for the preoperative diagnosis of Cushing's disease (CD). Clinical, endocrine, imaging, and histologic data from 252 patients undergoing pituitary surgery at Toranomon Hospital through the end of 2012 were entered into a database and statistically analyzed. In 22 of these patients (8.7%; positive venous sampling in 15 and negative venous sampling in 7 patients), tumors were invisible on magnetic resonance imaging (MRI) and 42.9% of them achieved remission. In the remaining 230 patients, 93.5% of those with microadenomas (n=154) and 71.1% of those with macroadenomas (n=76) achieved early postoperative remission, with recurrence rates of 2.7% and 14.8%, respectively, during a 72.5-month median follow-up. In multivariate analyses, cavernous sinus invasion (CSI; odds ratio [OR], 13.0), type of surgery (OR, 4.0), and tumor size (OR, 2.7) were significant preoperative factors affecting early postoperative results, whereas peak cortisol levels ≥9.4 μg/dL in response to corticotropin-releasing hormone (CRH) and CSI were significant factors predicting recurrence. Tumor recurrence was more common in patients with non-densely granulated adenomas than in patients with densely granulated adenomas. We propose that the higher remission and lower recurrence rates in this series are due to our surgical strategies, including extracapsular tumor removal, aggressive resection of tumors with CSI, extended transsphenoidal surgery (TSS), or a combined approach for large/giant adenomas. Appropriate multimodal treatments, including radiotherapy, medication, and repeated surgery in patients with persistent or recurrent CD, could result in better overall outcomes than previously achieved.

Downregulation of Insulin-like growth factor binding protein 6 is associated with ACTH-secreting pituitary adenoma growth

BACKGROUND

Adrenocorticotrophic hormone (ACTH)-dependent Cushing's syndrome, called Cushing disease, is caused by a corticotroph tumor of the pituitary gland. Insulin-like growth factor binding protein 6 (IGFBP6), which regulates insulin-like growth factor (IGF) activity and inhibits several IGF2-dependent cancer growths, plays a pivotal role in the tumorigenesis of malignancy, but its roles in ACTH-secreting pituitary adenomas remain unclear.

OBJECTIVE

To investigate IGFBP6 expression in ACTH-secreting pituitary adenomas, and its involvement in tumor growth.

METHODS

Sporadic ACTH-secreting pituitary adenomas specimens (n = 41) and adjacent non-tumorous pituitary tissues (n = 9) were collected by transphenoidal surgery. IGFBP6 expression was assessed by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) and validated by Western blotting. Associations of IGFBP6 expression with maximum tumor diameter or Ki-67 labeling index were evaluated in ACTH-secreting pituitary adenomas.

RESULTS

IGFBP6 mRNA and protein expression were both decreased in ACTH-secreting pituitary adenomas, compared to adjacent non-tumorous pituitary tissues (P < 0.01). IGFBP6 expression was correlated inversely with maximum tumor diameter (Rho = -0.53, P < 0.0001) and Ki-67 levels (Rho = -0.52, P < 0.05). Moreover, IGFBP6 downregulation activated PI3 K-AKT-mTOR pathway in ACTH-secreting pituitary adenomas.

CONCLUSIONS

IGFBP6 attenuation in ACTH-secreting pituitary adenomas is associated with tumor growth, through activation of PI3K-AKT-mTOR pathway. The finding underlies IGFBP6 roles in Cushing disease and would potentially provide a novel target of medical therapies.

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.

Morbidity of repeat transsphenoidal surgery assessed in more than 1000 operations

Object

While transsphenoidal surgery is associated with low morbidity, the degree to which morbidity increases after reoperation remains unclear. The authors determined the morbidity associated with repeat versus initial transsphenoidal surgery after 1015 consecutive operations.

Methods

The authors conducted a 5-year retrospective review of the first 916 patients undergoing transsphenoidal surgery at their institution after a pituitary center of expertise was established, and they analyzed morbidities.

Results

The authors analyzed 907 initial and 108 repeat transsphenoidal surgeries performed in 916 patients (9 initial surgeries performed outside the authors' center were excluded). The most common diagnoses were endocrine inactive (30%) or active (36%) adenomas, Rathke's cleft cysts (10%), and craniopharyngioma (3%). Morbidity of initial surgery versus reoperation included diabetes insipidus ([DI] 16% vs 26%; p = 0.03), postoperative hyponatremia (20% vs 16%; p = 0.3), new postoperative hypopituitarism (5% vs 8%; p = 0.3), CSF leak requiring repair (1% vs 4%; p = 0.04), meningitis (0.4% vs 3%; p = 0.02), and length of stay ([LOS] 2.8 vs 4.5 days; p = 0.006). Of intraoperative parameters and postoperative morbidities, 1) some (use of lumbar drain and new postoperative hypopituitarism) did not increase with second or subsequent reoperations (p = 0.3–0.9); 2) some (DI and meningitis) increased upon second surgery (p = 0.02–0.04) but did not continue to increase for subsequent reoperations (p = 0.3–0.9); 3) some (LOS) increased upon second surgery and increased again for subsequent reoperations (p < 0.001); and 4) some (postoperative hyponatremia and CSF leak requiring repair) did not increase upon second surgery (p = 0.3) but went on to increase upon subsequent reoperations (p = 0.001–0.02). Multivariate analysis revealed that operation number, but not sex, age, pathology, radiation therapy, or lesion size, increased the risk of CSF leak, meningitis, and increased LOS. Separate analysis of initial versus repeat transsphenoidal surgery on the 2 most common benign pituitary lesions, pituitary adenomas and Rathke's cleft cysts, revealed that the increased incidence of DI and CSF leak requiring repair seen when all pathologies were combined remained significant when analyzing only pituitary adenomas and Rathke's cleft cysts (DI, 13% vs 35% [p = 0.001]; and CSF leak, 0.3% vs 9% [p = 0.0009]).

Conclusions

Repeat transsphenoidal surgery was associated with somewhat more frequent postoperative DI, meningitis, CSF leak requiring repair, and greater LOS than the low morbidity characterizing initial transsphenoidal surgery. These results provide a framework for neurosurgeons in discussing reoperation for pituitary disease with their patients.

Retinoic acid receptor-α up-regulates proopiomelanocortin gene expression in AtT20 corticotroph cells

Cushing's disease is a disorder caused by excessive ACTH secretion from a corticotroph tumor of the pituitary gland. Although its standard therapy is a transsphenoidal surgery, innovation of novel medical treatments for the disease is urgently necessary. Retinoic acid (RA) has been reported to suppress adrenocorticotropic hormone (ACTH) secretion in Cushing's disease. However, the role of RA receptor (RAR) in proopiomelanocortin (Pomc) gene expression remains uncertain. We here examined the involvement of RARα in Pomc regulation using AtT20 corticotroph cells. Surprisingly, a synthetic RARα agonist Am80 increased Pomc mRNA expression, CRH-induced ACTH secretion, and Pomc promoter activity. Small interfering RNA-mediated RARα-knockdown suppressed both basal and Am80-induced Pomc promoter activity. RARα-overexpression dose-dependently increased Pomc promoter activity. Pomc promoter mutation analysis revealed that both Tpit and NeuroD1 binding elements were responsible for the Am80-mediated effect. Am80 increased Tpit expression while RAR antagonist LE540 suppressed the increase. Tpit-overexpression increased Pomc promoter activity. Mammalian two-hybrid assay revealed that Am80 induced NeuroD1-RARα interaction. NeuroD1-overexpression enhanced the Am80-induced Pomc promoter activity, which was suppressed by NeuroD1 truncated mutant-overexpression. RARα thus positively regulates ACTH secretion/Pomc gene expression through interaction with NeuroD1 and Tpit expression increase. The present observation will be useful for the future development of the RA/retinoid-derived therapeutics of the disease.

Approach to the Cushing's disease patient with persistent/recurrent hypercortisolism after pituitary surgery

Although it is the ideal treatment, pituitary surgery is not always successful, and success is not always lasting. Close surveillance, clinical and biological, will detect immediate failure or late recurrence. The reason must be thoroughly explored with the somewhat dogmatic rule that the patient should be offered the best surgery in expert hands, and a repeat surgical attempt must be systematically discussed. When repeat pituitary surgery is not indicated or has failed, then comes the difficult task to choose between a number of options directed toward different targets: directly suppress tumor ACTH by pituitary radiotherapy (conventional or stereotaxic) or with medications (somatostatin analog such as pasireotide, or dopaminergic drug such as cabergoline), directly suppress adrenocortical activity with medications (inhibitors of adrenal steroidogenesis such as ketoconazole or metyrapone, or the adrenolytic Lysodren), or by surgery (bilateral adrenalectomy), and finally oppose peripheral cortisol action with the antiglucocorticoid mifepristone. No single option is ideal, able to provide at the same time a high success rate and a rapid onset of action, to restore a normal pituitary adrenal axis, and to have good tolerability. Close follow-up and thorough evaluation of the cortisolic status will eventually dictate a switch in treatment options and/or combination strategies over time. The tumor status and its possible oncogenic threat, the severity of the hypercortisolism, and the patient perspectives (wish of fertility) are among the major parameters that can help a multidisciplinary approach toward the best option.

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.

Diagnosis and Multimodality Management of Cushing's Disease: A Practical Review

Cushing's Disease is caused by oversecretion of ACTH from a pituitary adenoma and results in subsequent elevations of systemic cortisol, ultimately contributing to reduced patient survival. The diagnosis of Cushing's Disease frequently involves a stepwise approach including clinical, laboratory, neuroimaging, and sometimes interventional radiology techniques, often mandating multidisciplinary collaboration from numerous specialty practitioners. Pituitary microadenomas that do not appear on designated pituitary MRI or dynamic contrast protocols may pose a particularly challenging subset of this disease. The treatment of Cushing's Disease typically involves transsphenoidal surgical resection of the pituitary adenoma as a first-line option, yet may require the addition of adjunctive measures such as stereotactic radiosurgery or medical management to achieve normalization of serum cortisol levels. Vigilant long-term serial endocrine monitoring of patients is imperative in order to detect any recurrence that may occur, even years following initial remission. In this paper, a stepwise approach to the diagnosis, and various management strategies and associated outcomes in patients with Cushing's Disease are discussed.

Cushing's disease

Cushing’s disease, or pituitary ACTH dependent Cushing’s syndrome, is a rare disease responsible for increased morbidity and mortality. Signs and symptoms of hypercortisolism are usually non specific: obesity, signs of protein wasting, increased blood pressure, variable levels of hirsutism. Diagnosis is frequently difficult, and requires a strict algorithm. First-line treatment is based on transsphenoidal surgery, which cures 80% of ACTH-secreting microadenomas. The rate of remission is lower in macroadenomas. Other therapeutic modalities including anticortisolic drugs, radiation techniques or bilateral adrenalectomy will thus be necessary to avoid long-term risks (metabolic syndrome, osteoporosis, cardiovascular disease) of hypercortisolism. This review summarizes potential pathophysiological mechanisms, diagnostic approaches, and therapies.

Efficacy of cabergoline in uncured (persistent or recurrent) Cushing disease after pituitary surgical treatment with or without radiotherapy

OBJECTIVE

To evaluate the efficacy of cabergoline therapy in patients with Cushing disease who remained uncured (had persistent or recurrent disease) after a pituitary surgical procedure with or without radiotherapy.

METHODS

We undertook a prospective, open-label, single-arm study, with short-term (5 months) and longterm (1 year) evaluations. In 20 patients with uncured Cushing disease, treatment was initiated with cabergoline at a dosage of 1 mg/wk, with a monthly increment of 1 mg, until midnight serum cortisol (MNSC) or low-dose dexamethasone suppression serum cortisol (LDSC) (or both) normalized or a maximal dosage of 5 mg/wk was reached.

RESULTS

Overall, 5 of 18 patients (28%) responded in terms of LDSC or MNSC (or both) at a mean dosage of 3.6 mg/wk (range, 2 to 5). When the response was defined with use of either LDSC or MNSC level as an isolated criterion, it was achieved in 4 of 16 patients (25%) and 3 of 18 patients (17%), respectively. Four patients were treated for 1 year, and the response was persistent in 2 and 3 patients on the basis of MNSC and LDSC levels, respectively. Lower baseline serum cortisol (basal, MNSC, and LDSC) values were predictive of a therapeutic response.

CONCLUSION

Cabergoline was an effective therapy in 28%, 25%, and 17% of patients with uncured Cushing disease in terms of LDSC or MNSC (or both), LDSC alone, and MNSC alone, respectively. Further studies are needed to address the persistence of the drug response and the effects on the dynamics of the hypothalamic-pituitary-adrenal axis.

Understanding sarcopenia as a geriatric syndrome

PURPOSE OF REVIEW

Highly prevalent in the population older than 65 years and leading to poor outcomes (functional decline and its related consequences), sarcopenia does not benefit yet either of a clear understanding of its pathophysiology or of precise clinical or biological markers allowing its identification.

RECENT FINDINGS

The new scientific definition of 'geriatric syndromes' challenges the authors to review the current sarcopenia literature, allowing them to affirm that sarcopenia cannot be considered as an age-related disease but as a true 'geriatric syndrome'. More than 50% of the population older than 80 years suffer from this medical condition, which is linked to multiple causations: the ageing process itself, genetic susceptibility, certain life habits, changes in living conditions and a number of chronic diseases. Moreover, sarcopenia favours poor outcomes such as mobility disorders, disability, poor quality of life and death.

SUMMARY

Considering sarcopenia as a geriatric syndrome allows us to request its recognition and assess its multiple risk factors, to implement a clinical and public health approach to the management of sarcopenic patients and population at risk and to disentangle the links among sarcopenia, frailty, disability and mortality.