Neurosurgical Treatment of Cushing Disease

Prospective Evaluation of Late-Night Salivary Cortisol and Cortisone by EIA and LC-MS/MS in Suspected Cushing Syndrome

Context

Late-night salivary cortisol (LNSC) measured by enzyme immunoassay (EIA-F) is a first-line screening test for Cushing syndrome (CS) with a reported sensitivity and specificity of >90%. However, liquid chromatography-tandem mass spectrometry, validated to measure salivary cortisol (LCMS-F) and cortisone (LCMS-E), has been proposed to be superior diagnostically.

Objective, Setting, and Main Outcome Measures

Prospectively evaluate the diagnostic performance of EIA-F, LCMS-F, and LCMS-E in 1453 consecutive late-night saliva samples from 705 patients with suspected CS.

Design

Patients grouped by the presence or absence of at least one elevated salivary steroid result and then subdivided by diagnosis.

Results

We identified 283 patients with at least one elevated salivary result; 45 had an established diagnosis of neoplastic hypercortisolism (CS) for which EIA-F had a very high sensitivity (97.5%). LCMS-F and LCMS-E had lower sensitivity but higher specificity than EIA-F. EIA-F had poor sensitivity (31.3%) for adrenocorticotropic hormone (ACTH)-independent CS (5 patients with at least 1 and 11 without any elevated salivary result). In patients with Cushing disease (CD), most nonelevated LCMS-F results were in patients with persistent/recurrent CD; their EIA-F levels were lower than in patients with newly diagnosed CD.

Conclusions

Since the majority of patients with ≥1 elevated late-night salivary cortisol or cortisone result did not have CS, a single elevated level has poor specificity and positive predictive value. LNSC measured by EIA is a sensitive test for ACTH-dependent Cushing syndrome but not for ACTH-independent CS. We suggest that neither LCMS-F nor LCMS-E improves the sensitivity of late-night EIA-F for CS.

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.

Endoscopic Transsphenoidal Surgery for Cushing's Disease: A Review

Ever since the 1960s, transsphenoidal surgery has been the modality of choice for treating Cushing's disease. Subsequent visualization of the pituitary fossa and sphenoid sinus may be done either with the operating microscope or with the relatively new endoscope. The endoscope due to its panoramic view allows greater visualization as compared to the operating microscope. It confers greater access to the cavernous sinus, sella, suprasellar, and parasellar regions and accommodates higher magnifications. It is bi-dimensional, however as opposed to the operating microscope that provides a three-dimensional view and allows greater depth perception. This article provides a comprehensive review of the advantages and disadvantages of the endoscope and compares it to the operating microscope. We hope this article will prove useful to both clinicians and academicians alike in their approach and management of Cushing's disease.

Outcome of Transsphenoidal Surgery for Cushing Disease: A Single-Center Experience over 20 Years

BACKGROUND

This study investigated the outcome of transsphenoidal surgery (TSS) for Cushing disease (CD) and the influence of our surgical strategy on remission rates and postoperative pituitary function.

PATIENTS AND METHODS

We retrospectively reviewed data from 71 patients with CD who underwent microscope navigation TSS (MN-TSS) in Saint-Luc Hospital between 1996 and 2017. True remission was defined as normal fasting cortisol level, normal 24-hour urinary free cortisol, or continued need for hydrocortisone replacement for 1 year after surgery.

RESULTS

Overall remission rate after 1 or repeated MN-TSS was 83%. Highest remission rate was found in patients with macroadenomas (92%). Successful first MN-TSS was correlated with a high final remission rate (95%), whereas failed first MN-TSS was correlated with a low final remission rate (36%). Although day 1 cortisol levels were significantly lower in patients with long-term remission, high levels were still observed in a few patients, especially those who had had CD for many years. We found a low rate of postoperative pituitary long-term hypofunction (9.7%).

CONCLUSIONS

MN-TSS is a safe and effective procedure to treat CD, allowing remission rates of 83%. One-year remission period after first surgery is correlated with a final remission rate of 95%. Although day 1 morning cortisol value is the most significant predictor for long-term remission, some patients with CD for many years may keep high postoperative cortisol levels and be in later remission, likely because of secondary adrenal hyperplasia. Our focused approach with microscope navigation resulted in low rates of postoperative pituitary hypofunction and kept a recurrence rate comparable to that in the literature.

Prognostic Factors of Long-Term Remission After Surgical Treatment of Cushing's Disease

Transsphenoidal surgery is the main treatment of patients with adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas. Although biochemical remission occurs in most patients undergoing operations at specialized centers, the recurrence risk is significant. Visualization of microadenomas on preoperative imaging and confirmation of ACTH-positive adenomas have been associated with higher remission rates. Low cortisol levels in the first 2 weeks postoperatively have been associated with durable remission; however, recurrence cannot be excluded by any cortisol threshold. The decision to perform a pituitary reoperation is based on this parameter; the protocols are institution specific. Patients with Cushing's disease warrant lifelong endocrinologic surveillance.

A review of Cushing's disease treatment by the Department of Neuroendocrinology of the Brazilian Society of Endocrinology and Metabolism

The treatment objectives for a patient with Cushing's disease (CD) are remission of hypercortisolism, adequate management of co-morbidities, restoration of the hypothalamic-pituitary-adrenal axis, preservation of fertility and pituitary function, and improvement of visual defects in cases of macroadenomas with suprasellar extension. Transsphenoidal pituitary surgery is the main treatment option for the majority of cases, even in macroadenomas with low probability of remission. In cases of surgical failure, another subsequent pituitary surgery might be indicated in cases with persistent tumor imaging at post surgical magnetic resonance imaging (MRI) and/or pathology analysis of adrenocorticotropic hormone-positive (ACTH+) positive pituitary adenoma in the first procedure. Medical treatment, radiotherapy and adrenalectomy are the other options when transsphenoidal pituitary surgery fails. There are several options of medical treatment, although cabergoline and ketoconazole are the most commonly used alone or in combination. Novel treatments are also addressed in this review. Different therapeutic approaches are frequently needed on an individual basis, both before and, particularly, after surgery, and they should be individualized. The objective of the present review is to provide the necessary information to achieve a more effective treatment for CD. It is recommended that patients with CD be followed at tertiary care centers with experience in treating this condition.

Surgical management of adrenocorticotropic hormone-secreting pituitary adenomas

Cushing's disease is defined as hypercortisolemia caused by secretion of adrenocorticotropic hormone from a pituitary adenoma. The diagnosis of Cushing's disease is based on clinical symptoms, laboratory and imaging findings. Once an adrenocorticotropic-hormone-secreting adenoma is found, the standard of care is transsphenoidal adenomectomy. MRI negative microadenomas and large, invasive macroadenomas provide a surgical and clinical challenge and are best handled at high volume centers. Multiple options exist for refractory disease or recurrence, including repeat surgery, radiosurgery and radiotherapy, medical management and bilateral adrenalectomy.

The Role of Isotretinoin Therapy for Cushing's Disease: Results of a Prospective Study

Objective. This prospective open trial aimed to evaluate the efficacy and safety of isotretinoin (13-cis-retinoic acid) in patients with Cushing's disease (CD). Methods. Sixteen patients with CD and persistent or recurrent hypercortisolism after transsphenoidal surgery were given isotretinoin orally for 6-12 months. The drug was started on 20 mg daily and the dosage was increased up to 80 mg daily if needed and tolerated. Clinical, biochemical, and hormonal parameters were evaluated at baseline and monthly for 6-12 months. Results. Of the 16 subjects, 4% (25%) persisted with normal urinary free cortisol (UFC) levels at the end of the study. UFC reductions of up to 52.1% were found in the rest. Only patients with UFC levels below 2.5-fold of the upper limit of normal achieved sustained UFC normalization. Improvements of clinical and biochemical parameters were also noted mostly in responsive patients. Typical isotretinoin side-effects were experienced by 7 patients (43.7%), though they were mild and mostly transient. We also observed that the combination of isotretinoin with cabergoline, in relatively low doses, may occasionally be more effective than either drug alone. Conclusions. Isotretinoin may be an effective and safe therapy for some CD patients, particularly those with mild hypercortisolism.

The role of bilateral adrenalectomy in the treatment of refractory Cushing's disease

Cushing's syndrome (CS) results from sustained exposure to excessive levels of free glucocorticoids. One of the main causes of CS is excessive adrenocorticotropic hormone (ACTH) secretion by tumors in the pituitary gland (Cushing's disease [CD]). Cushing's disease and its associated hypercortisolism have a breadth of debilitating symptoms associated with an increased mortality rate, warranting urgent treatment. Currently, the first line of treatment for CD is transsphenoidal surgery (TSS), with excellent long-term results. Transsphenoidal resections performed by experienced surgeons have shown remission rates ranging from 70% to 90%. However, some patients do not achieve normalization of their hypercortisolemic state after TSS and continue to have persistent or recurrent CD. For these patients, various therapeutic options after failed TSS include repeat TSS, radiotherapy, medical therapy, and bilateral adrenalectomy (BLA). Bilateral adrenalectomy has been shown to be a safe and effective treatment modality for persistent or recurrent CD with an immediate and definitive cure of the hypercortisolemic state. BLA was traditionally performed through an open approach, but since the advent of laparoscopic adrenalectomy, the laparoscopic approach has become the surgical method of choice. Advances in technology, refinement in surgical skills, competency in adrenopathology, and emphasis on multidisciplinary collaborations have greatly reduced morbidity and mortality associated with adrenalectomy surgery in a high-risk patient population. In this article, the authors review the role of BLA in the treatment of refractory CD. The clinical indications, current surgical and endocrinological results reported in the literature, surgical technique (open vs laparoscopic), drawbacks, and complications of BLA are discussed.

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.

Medical combination therapies in Cushing's disease

INTRODUCTION

There has been growing interest on medical therapy for the management of Cushing's disease (CD), particularly in cases of persistent or recurrent hypercortisolism. Ketoconazole, an inhibitor of adrenal steroidogenesis, is the most widely used drug, whereas cabergoline and pasireotide are the most promising centrally acting agents. The main purpose of this review article is to highlight the options of medical treatment for CD, with a special emphasis on combination therapies, a topic that has only been addressed by a limited number of studies.

CONCLUSIONS

According to the results of these studies, combination therapies involving medications with additive or synergistic effects on ACTH and cortisol secretion seem quite attractive as they yield higher probability of longterm control of the hypercortisolism at lower doses, a lower incidence of side-effects, and possibly a lower rate of treatment escapes. Currently, ketoconazole, cabergoline, and pasireotide are the best drugs to be prescribed in combination.