Biochemical predictors of outcome of pituitary surgery for Cushing's disease

Clinicoradiological Parameters and Biochemical and Molecular Alterations Predicting Remission and Recurrence After Surgical Treatment of Corticotroph Adenomas-Cushing Disease

OBJECTIVE

Endonasal endoscopic transsphenoidal surgery (TSS) and resection of pituitary adenomas are considered the gold standard treatment for Cushing disease (CD). Even with various recent advances in management, disease persistence and recurrence are common in these patients. The remission rate in the global population after surgery has been reported to vary widely from 64% to 93%. This study aims to determine the various clinical, biochemical, radiological, and histological factors that correlate with persistence and recurrence in patients with CD. This study also aims to understand the clinicopathological significance of EGFR-MAPK, NF-κB, and SHH pathway activation and to study the protein expression of activation markers of these pathways (i.e., c-Fos, c-Jun, GLI-1, pMEK, NR4A1, and p44) in functioning corticotroph pituitary adenomas.

METHODS

From January 2009 to September 2022, the clinical data of 167 patients who underwent surgical treatment (n = 174 surgeries) for CD with a median follow-up of 8.1 years (range, 1-13.29 years) were ambispectively analyzed. The preoperative clinical, biochemical, and radiological features, operative findings, postoperative clinical and biochemical data, and histopathological and molecular profiles were retrieved from the electronic medical records. The patients were followed up to assess their remission status.

RESULTS

Among the 174 surgeries performed, 140 were primary surgeries, 22 were revision surgeries, 24 surgeries were for pediatric patients, and 12 surgeries were for patients with Nelson syndrome. In the primary surgery cohort, 74.3% were female, and the average age was 28.73 ± 10.15 years. Of the primary surgery cohort, 75% of the patients experienced remission compared with 47.4% after revision surgery. The remission rate for the pediatric patients was 55.5%. The postoperative day 1 plasma cortisol (P < 0.001; area under the curve, 0.8894; range, 0.8087-0.9701) and adrenocorticotropic hormone (P < 0.001; area under the curve, 0.9; range, 0.7386-1) levels were seen to be strong independent predictors of remission in the primary surgery cohort. The remission rate after endoscopic TSS was greater than that after microscopic TSS in patients undergoing primary surgery (81.08% vs. 57.14%; P = 0.008). The presence of adenoma on histopathological examination (HPE) was also a strong predictor of disease remission (P = 0.020). On stratifying by surgical approach and HPE, microscopically operated patients without histopathological evidence of adenoma had significantly higher odds of nonremission (odds ratio, 38.1; 95% confidence interval, 4.2-348.3) compared with endoscopically operated patients with adenoma found on HPE. A lower immunoreactivity score for NR4A1 was found to correlate with higher remission rates (P = 0.074). However, none of the molecular markers studied (i.e., c-Fos, c-Jun, GLI-1, pMEK, and p44) showed a significant correlation with the preoperative cortisol values.

CONCLUSIONS

The remission rate after primary surgery is higher than that after revision surgery and is lower for pediatric patients than for adults. The postoperative day 1 plasma cortisol and adrenocorticotropic hormone levels are strong independent predictors of remission in the primary surgery cohort. An endoscopic approach with histopathological evidence of adenoma is associated with a higher remission rate; thus, endoscopy should be the approach of choice for these patients with the goal of identification of an adenoma on HPE.

Exoscopic vs. microscopic transsphenoidal surgery for Cushing's disease: a retrospective single-center study on 388 patients

Microscopic and endoscopic transsphenoidal surgeries represent the standard treatment for Cushing's disease (CD). At our institution a new exoscopic approach was implemented. After proof of the general use for transsphenoidal pituitary surgery, the aim of this study was to compare the exoscopic 4K3D video microscope with the microscopic transsphenoidal surgery for patients with CD. We conducted a retrospective analysis on 388 patients with CD treated in our medical center via microscopic transsphenoidal surgery (MTS) between January 2008 and July 2019 or via exoscopic transsphenoidal surgery (ExTS) between May 2019 and May 2021. Parameters investigated included histology, pre- and postoperative MRI with tumor size, pre- and postoperative ACTH and cortisol levels, duration of surgery, perioperative and postoperative complications as well as clinical outcome. Patients who underwent ExTS in CD experienced a lower incidence of SIADH/diabetes insipidus (p = 0.0164), a higher rate of remission (p = 0.0422), and a shorter duration of surgery (p < 0.0001), compared to MTS. However, there was no significant difference regarding new postoperative pituitary insufficiency and intraoperative CSF space opening. We found that ExTS had multiple benefits compared to MTS for tumor resection in case of CD. These results are in line with our previous publication on the general applicability of an exoscope in pituitary surgery. To our knowledge, this is the first clinical study proving the superiority of ExTS in CD. These results are promising, nevertheless further studies comparing exoscopic with the endoscopic approach are necessary to finally evaluate the utility of the new technique.

Long-term follow-up and predictors of recurrence of Cushing's disease

Transsphenoidal surgery is the first-line treatment for Cushing's disease to selectively remove the tumor. The rate of postoperative remission is estimated around 70%-80% in expert centers. However, the long-term remission rate is lower because of recurrence during follow-up that can be observed in 15% to 25% of the patients depending on the studies and duration of follow-up. There is no significant predictive factor of recurrence before surgery, but postoperative corticotroph insufficiency and its duration has been found to be a protective factor for recurrence in many studies. The persistence of a positive response to desmopressin after surgery is associated with a higher rate of recurrence. Long term monitoring for recurrence with annual clinical and hormonal investigations after the hypothalamic-pituitary-adrenal axis postoperative recovery is advised. The biological tests used for the diagnosis of Cushing's syndrome (24 h-urinary-free cortisol [UFC], late-night salivary or serum cortisol, 1 mg dexamethasone suppression test) can be used to screen for recurrence. Several studies report that increased late night cortisol and alterations of dynamic testing can be observed before the increased 24 h-UFC. For this reason it is suggested that late-night salivary cortisol would be a very sensitive tool to diagnose recurrence, pending the realization of several assays in case of borderline or discrepant result. This review will summarize the knowledge about recurrence of Cushing's disease after pituitary surgery and the current recommendations for its monitoring and diagnosis.

A Comprehensive Approach to Predicting the Outcomes of Transsphenoidal Endoscopic Adenomectomy in Patients with Cushing’s Disease

Persistent and recurrent hypercortisolism after transsphenoidal endoscopic surgery (TSS) is considered to be an urgent issue prompting the search for Cushing’s disease (CD) remission predictors. The goal was to find a combination of predictors that can forecast the remission of CD after TSS. A total of 101 patients with CD who had undergone TSS were included. One year after surgery, CD remission status was evaluated. Preoperative pituitary magnetic resonance imaging (MRI) data, preoperative results of a high-dose dexamethasone suppression test (HDDST) and morning serum cortisol level collected 24 h after TSS (24 h MSeC) were compared in patients with and without remission of hypercortisolism. Remission one year after TSS was confirmed in 63 patients. CD remission predictors one year after TSS were: adenoma size ≥ 3 mm in the absence of invasive growth and the suppression of serum cortisol ≥ 74% in the HDDST, 24 h MSeC ≤ 388 nmol/L. A total of 38 patients had three favorable values of detected predictors; all of them had CD remission one year after TSS. With long-term follow-up, 36 of them remained in remission. Patients who had no one favorable predictor had no remission of hypercortisolism one year after TSS. Our data confirmed the prospects of using a combination of selected predictors to forecast CD remission after TSS.

Consensus statement by the French Society of Endocrinology (SFE) and French Society of Pediatric Endocrinology & Diabetology (SFEDP) on diagnosis of Cushing's syndrome

Cushing's syndrome is defined by prolonged exposure to glucocorticoids, leading to excess morbidity and mortality. Diagnosis of this rare pathology is difficult due to the low specificity of the clinical signs, the variable severity of the clinical presentation, and the difficulties of interpretation associated with the diagnostic methods. The present consensus paper by 38 experts of the French Society of Endocrinology and the French Society of Pediatric Endocrinology and Diabetology aimed firstly to detail the circumstances suggesting diagnosis and the biologic diagnosis tools and their interpretation for positive diagnosis and for etiologic diagnosis according to ACTH-independent and -dependent mechanisms. Secondly, situations making diagnosis complex (pregnancy, intense hypercortisolism, fluctuating Cushing's syndrome, pediatric forms and genetically determined forms) were detailed. Lastly, methods of surveillance and diagnosis of recurrence were dealt with in the final section.

Low but not undetectable early postoperative nadir serum cortisol predicts sustained remission in Cushing's disease

Objective

Transsphenoidal surgery (TSS) is the first-line treatment for Cushing's disease. The objectives of the study were to determine remission and recurrence rates after TSS for Cushing's disease, identify factors that predict these outcomes, and define the threshold for postoperative morning serum cortisol (MSeC) that most accurately predicts sustained remission.

Methods

Records were retrospectively reviewed for consecutive adults undergoing TSS for Cushing's disease at a tertiary centre (1990-2019). Remission was defined as MSeC <138 nmol/L by 6 weeks postoperatively. Recurrence was defined as elevated 24-h urine free cortisol, lack of suppression after dexamethasone or elevated midnight salivary cortisol.

Results

In this study, 42 patients (age 47 ± 13 years, 83% female) were assessed with 55 ± 56 months of follow-up. Remission occurred after 77% of primary (n = 30) and 42% of revision operations (n = 12). After primary surgery, remission was associated with lower MSeC nadir (26 ± 36 nmol/L vs 347 ± 220 nmol/L, P  < 0.01) and lower adrenocorticotropin nadir (2 ± 3 pmol/L vs 6 ± 3 pmol/L, P = 0.01). Sustained remission 5 years after surgery was predicted by MSeC <92 nmol/L within 2 weeks postoperatively (sensitivity 100% and specificity 100%). After revision surgery, remission was predicted by lower MSeC nadir (70 ± 45 nmol/L vs 408 ± 305 nmol/L, P = 0.03), smaller tumour diameter (3 ± 2 mm vs 15 ± 13 mm, P = 0.05) and absence of cavernous sinus invasion (0% vs 71%, P = 0.03). Recurrence after primary and revision surgery occurred in 17% and 20% of patients respectively.

Conclusions

Lower postoperative MSeC nadir strongly predicted remission after both primary and revision surgery. Following primary surgery, an MSeC <92 nmol/L within 2 weeks predicted sustained remission at 5 years. MSeC nadir was the most important prognostic marker following TSS for Cushing's disease.

Remission in Cushing's disease is predicted by cortisol burden and its withdrawal following pituitary surgery

AIM

To ascertain the predictors of remission and relapse in patients of Cushing's disease (CD) undergoing pituitary transsphenoidal surgery (TSS).

METHODS

Patients with CD subjected to TSS over 35 years at a tertiary care center were included. Patients were grouped into remission and persistent disease at 1 year after surgery, and were further followed up for relapse. Demographic, clinical, biochemical, histological, radiological and post-operative follow-up parameters were analyzed.

RESULTS

Of the 152 patients of CD, 145 underwent TSS. Remission was achieved in 95 (65.5%) patients at 1 year. Patients in remission had shorter duration of symptoms prior to presentation (p = 0.009), more frequent presence of proximal myopathy (p = 0.038) and a tumor size of < 2.05 cm (p = 0.016) in comparison to those with persistent disease. Post-TSS, immediate post-operative 0800-h cortisol (< 159.85 nmol/L; p = 0.001), histological confirmation of tumor (p = 0.045), duration of glucocorticoid replacement (median 90 days; p = 0.001), non-visualization of tumor on MRI (p = 0.003), new-onset hypogonadism (p = 0.001), 3-month 0800-h cortisol (< 384.9 nmol/L; p = 0.001), resolution of diabetes (p = 0.001) and hypertension (p = 0.001), and recovery of hypothalamic-pituitary-adrenal axis (p = 0.018) favored remission. In logistic regression model, requirement of glucocorticoid replacement (p = 0.033), and resolution of hypertension post-TSS (p = 0.003) predicted remission. None of the parameters could predict relapse.

CONCLUSION

The study could ascertain the predictors of remission in CD. Apart from the tumor characteristics, surgical aspects and low post-operative 0800-h cortisol, the results suggest that baseline clinical parameters, longer glucocorticoid replacement, and resolution of metabolic complications post-TSS predict remission in CD. Long-term follow-up is essential to look for relapse.

Development of Machine Learning Models for Predicting Postoperative Delayed Remission in Patients With Cushing's Disease

CONTEXT

Postoperative hypercortisolemia mandates further therapy in patients with Cushing's disease (CD). Delayed remission (DR) is defined as not achieving postoperative immediate remission (IR), but having spontaneous remission during long-term follow-up.

OBJECTIVE

We aimed to develop and validate machine learning (ML) models for predicting DR in non-IR patients with CD.

METHODS

We enrolled 201 CD patients, and randomly divided them into training and test datasets. We then used the recursive feature elimination (RFE) algorithm to select features and applied 5 ML algorithms to construct DR prediction models. We used permutation importance and local interpretable model-agnostic explanation (LIME) algorithms to determine the importance of the selected features and interpret the ML models.

RESULTS

Eighty-eight (43.8%) of the 201 CD patients met the criteria for DR. Overall, patients who were younger, had a low body mass index, a Knosp grade of III-IV, and a tumor not found by pathological examination tended to achieve a lower rate of DR. After RFE feature selection, the Adaboost model, which comprised 18 features, had the greatest discriminatory ability, and its predictive ability was significantly better than using Knosp grading and postoperative immediate morning serum cortisol (PoC). The results obtained from permutation importance and LIME algorithms showed that preoperative 24-hour urine free cortisol, PoC, and age were the most important features, and showed the reliability and clinical practicability of the Adaboost model in DC prediction.

CONCLUSIONS

Machine learning-based models could serve as an effective noninvasive approach to predicting DR, and could aid in determining individual treatment and follow-up strategies for CD patients.

Predictors of Immediate Remission after Surgery in Cushing's Disease Patients: A Large Retrospective Study from a Single Center

OBJECTIVE

Transsphenoidal surgery (TSS) is the first-line treatment of patients with Cushing's disease (CD). However, biochemical remission rates after TSS for CD vary from 59 to 95%, and the predictors of surgical outcomes remain unclear. The aim of this study was to identify the predictors of early outcomes in patients with CD treated with TSS.

METHODS

The clinical features and outcomes of CD patients who underwent TSS between February 2000 and September 2019 at the Peking Union Medical College Hospital were collected from medical records and analyzed. Uni- and multivariate odds ratio (OR) analyses were performed to identify the predictors of early outcomes in patients with CD.

RESULTS

A total of 1,045 patients were included. The median age at TSS was 34.0 years (IQR 26.0-45.0), with a female:male ratio of 4.2:1 (844/201). The median duration of symptoms was 46.0 months (IQR 24.0-72.0). After surgery, the overall postoperative immediate remission rate was 73.3%, and 26.7% of patients had persistent hypercortisolism. Univariate analysis demonstrated that the number of operations was correlated with a lower immediate remission rate (OR 0.393, 95% CI 0.266-0.580, p = 0.000), as was tumor size (OR 0.462, 95% CI 0.334-0.639, p = 0.000), the duration of disease (OR 0.996, 95% CI 0.993-0.999, p = 0.003), and preoperative ACTH concentration (0.998, 95% CI 0.996-0.999, p = 0.003). Cavernous sinus invasion has also been identified as an important factor associated with a lower immediate remission rate (OR 0.275, 95% CI 0.166-0.456, p = 0.000). No correlations were detected between the immediate outcomes and age, gender, BMI, the combination of a low- and high-dose dexamethasone suppression test, preoperative morning serum cortisol level, or 24-h urinary free cortisol level (all p > 0.05). The results of multivariate analysis were similar to those of univariate analysis. Preoperative ACTH ≤67.35 ng/L predicted remission with 60.9% sensitivity and 49.5% specificity (AUC 0.553; p = 0.008). A cutoff of ≤64.5 months for disease duration predicted immediate remission with 40.5% sensitivity and 71.0% specificity (AUC 0.552; p = 0.01).

CONCLUSION

Early outcomes of TSS in CD patients can be predicted by factors including the number of operations, duration of disease, tumor invasion, tumor size, and preoperative ACTH concentration. These predictors can be used to improve the perioperative management of CD patients.

Outcomes of pituitary surgery for Cushing's disease: a systematic review and meta-analysis

PURPOSE

Transsphenoidal surgery (TSS) is the first-line treatment for Cushing's disease (CD). This review aimed to synthesize the remission and recurrence rates following TSS for CD and identify predictors of these outcomes.

METHODS

Medline (1946-) and Embase (1947-) were searched until 23rd January 2019 for original studies. A meta-analysis was performed of remission and recurrence rates. Studies were excluded if patients had prior radiosurgery/radiotherapy, mixed pathologies or interventions without separated data, follow-up not reported or population size < 20. For recurrence rate syntheses, studies with follow-up < 6 months were excluded.

RESULTS

The search produced 2663 studies, of which n = 68 were included, involving 5664 patients. Remission rates after primary and revision TSS were 80% [77-82] and 58% [50-66] at last follow-up. After primary TSS, predictors of remission were micro- v macroadenomas (83% v 68%, p < 0.01), imaging-visible adenomas (81% v 69%, p < 0.01), adenomas confirmed on histopathology (87% v 45%, p < 0.01), absence of cavernous sinus invasion (80% v 30%, p < 0.01), postoperative serum cortisol (MSeC) nadir < 2 μg/dL (< 55 nmol/L; 95% v 46%, p < 0.01) and lower preoperative 24-h urine free cortisol (1250 nmol v 1726 nmol, p < 0.01). For revision TSS, predictors of remission were postoperative MSeC nadir < 2 μg/dL (< 55 nmol/L; 100% v 38%, p < 0.01) and operations for recurrence v persistence (80% v 54%, p < 0.01). Recurrence rates after primary and revision TSS were 18% [14-22] and 28% [16-42].

CONCLUSIONS

TSS is most effective in primary microadenomas, visible on preoperative imaging and without CS invasion, lower preoperative 24-h urine free cortisol and postoperative MSeC nadir < 2 μg/dL (< 55 nmol/L).

Cushing's syndrome - Disease monitoring: Recurrence, surveillance with biomarkers or imaging studies

Pituitary surgery is the first-line treatment for patients with Cushing's disease. For patients who are not considered candidates for pituitary surgery, pituitary radiation and bilateral adrenalectomy are further treatment alternatives. Not all patients are cured with pituitary surgery, and a substantial number of patients develop recurrence, sometimes many years after an apparently successful treatment. The same applies to patients treated with radiotherapy. Far from all patients are cured, and in many cases the disease recurs. Bilateral adrenalectomy, although always curative, causes chronic adrenal insufficiency and the remaining pituitary tumour can continue to grow and cause symptoms due to pressure on adjacent tissues, a phenomenon called Nelson's syndrome. In this paper the rate of recurrence of hypercortisolism, as well as the rate of development of Nelson's syndrome, following treatment of patients with Cushing's syndrome, will be reviewed. The aim of the paper is also to summarize clinical and biochemical factors that are associated with recurrence of hypercortisolism and how the patients should be monitored following treatment.

Cushing's Disease

In patients with Cushing's disease (CD), prompt diagnosis and treatment are essential for favorable long-term outcomes, although this remains a challenging task. The differential diagnosis of CD is still difficult in some patients, even with an organized stepwise diagnostic approach. Moreover, despite the use of high-resolution magnetic resonance imaging (MRI) combined with advanced fine sequences, some tumors remain invisible. Surgery, using various surgical approaches for safe maximum tumor removal, still remains the first-line treatment for most patients with CD. Persistent or recurrent CD after unsuccessful surgery requires further treatment, including repeat surgery, medical therapy, radiotherapy, or sometimes, bilateral adrenalectomy. These treatments have their own advantages and disadvantages. However, the most important thing is that this complex disease should be managed by a multidisciplinary team with collaborating experts. In addition, a personalized and individual-based approach is paramount to achieve high success rates while minimizing the occurrence of adverse events and improving the patients' quality of life. Finally, the recent new insights into the pathophysiology of CD at the molecular level are highly anticipated to lead to the introduction of more accurate diagnostic tests and efficacious therapies for this devastating disease in the near future.

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.

Treatment challenges in pediatric Cushing's disease: Review of the literature with particular emphasis on predictive factors for the disease recurrence

Cushing's disease (CD) is a rare endocrine condition caused by a corticotroph pituitary tumor that produces adrenocorticotropic hormone. The current state of knowledge of CD treatment is presented in this article including factors that can be helpful in predicting remission and/or recurrence of the disease. The primary goals in CD treatment are quick diagnosis and effective, prompt treatment as the persistent disease is associated with increased morbidity and mortality. Cooperation of a team consisting of experienced pediatrician/adult endocrinologist, neuroradiologist, transsphenoidal neurosurgeon and (if necessary) radiotherapist contribute to the best treatment effects.

Prognostic usefulness of ACTH in the postoperative period of Cushing's disease

OBJECTIVES

To analyze the usefulness of plasma ACTH in predicting CD remission after surgery and to evaluate the prognostic usefulness of ACTH measurement after the cortisol and ACTH nadir (48 h prior to discharge).

DESIGN

A prospective study was made of 65 patients with CD operated upon between 2005 and 2016.

METHODS

Postsurgery plasma ACTH and cortisol were measured every 6 h, in the absence of corticosteroid coverage. Hydrocortisone was started in the presence of adrenal insufficiency or cortisol <55.2 nmol/L. Plasma ACTH was again determined before discharge.

MAIN OUTCOME MEASURE

Usefulness of plasma ACTH in predicting CD remission.

RESULTS

Remission at 3 months of CD was achieved in 56 of 65 cases, with late recurrence in 18 of 58 cases. Following resection, the ACTH nadir was significantly lower referred to late remission (2.8 vs 6.5 pmol/L; P = 0.031) and higher for recurrence (2.1 vs 4.8 pmol/L; P < 0.001), and identical results were obtained for the ACTH values before discharge. In the analysis of the ROC curves, nadir and before discharge ACTH values <1.9 pmol/L and <2.6 pmol/L were respectively indicative of early remission (AUC 0.827; P < 0.001); <6.2 pmol/L of remission at 3 months (AUC 0.847; P = 0.001) and >3.2 pmol/L of recurrence (AUC 0.810; P < 0.001) in both ACTH values. A time to ACTH nadir <46 h was indicative of early remission (AUC 0.751; P = 0.001), while a time >39 h was indicative of recurrence (AUC 0.773; P = 0.001).

CONCLUSIONS

We propose an ACTH value <3.3 pmol/L as a good long-term prognostic marker in the postoperative period of CD. Reaching the ACTH nadir in less time is associated to a lesser recurrence rate.

Recovery of Adrenal Function after Pituitary Surgery in Patients with Cushing Disease: Persistent Remission or Recurrence?

BACKGROUND

Cushing disease (CD) represents the principal cause of endogenous hypercortisolism. The first-line therapy of CD is surgical removal of the ACTH-secreting pituitary adenoma, which is generally followed by adrenal insufficiency (AI).

OBJECTIVE

To analyze the recovery of AI in patients with CD after pituitary surgery in relation with recurrence and persistent remission of CD.

PATIENTS AND METHODS

We performed a retrospective analysis of patients with CD who met the following inclusion criteria: adult age, presence of AI 2 months after the surgical intervention, and a minimum follow-up of 3 years after the surgical intervention.

RESULTS

Sixty-one patients were followed for a median of 6 years. Ten (16.4%) patients recurred during follow-up. The patients who restored adrenal function did so after a median time of 19 months, with a significantly shorter time in the recurrence group (12.5 vs. 25 months, p = 0.008). All 10 patients who recurred recovered their adrenal function within 22 months. The recovery rate of AI in the persistent remission group was 37.3% (19/51) at 3 years and 55.8% (24/43) at 5 years. In all patients the duration of AI was negatively associated with disease recurrence.

CONCLUSION

The duration of postsurgical AI in patients with recurrent CD is significantly shorter than that in patients with persistently remitted CD, and this parameter may be a useful predictor of recurrence. Patients showing a normal pituitary-adrenal axis within 2 years after surgery should be strictly monitored as they are at higher risk of disease relapse.

Endoscopic vs. microscopic transsphenoidal surgery for Cushing's disease: a systematic review and meta-analysis

PURPOSE

Systematic review and meta-analysis comparing endoscopic and microscopic transsphenoidal surgery for Cushing's disease regarding surgical outcomes (remission, recurrence, and mortality) and complication rates. To stratify the results by tumor size.

METHODS

Nine electronic databases were searched in February 2017 to identify potentially relevant articles. Cohort studies assessing surgical outcomes or complication rates after endoscopic or microscopic transsphenoidal surgery for Cushing's disease were eligible. Pooled proportions were reported including 95% confidence intervals.

RESULTS

We included 97 articles with 6695 patients in total (5711 microscopically and 984 endoscopically operated). Overall, remission was achieved in 5177 patients (80%), with no clear difference between both techniques. Recurrence was around 10% and short term mortality < 0.5% for both techniques. Cerebrospinal fluid leak occurred more often in endoscopic surgery (12.9 vs. 4.0%), whereas transient diabetes insipidus occurred less often (11.3 vs. 21.7%). For microadenomas, results were comparable between both techniques. For macroadenomas, the percentage of patients in remission was higher after endoscopic surgery (76.3 vs. 59.9%), and the percentage recurrence lower after endoscopic surgery (1.5 vs. 17.0%).

CONCLUSIONS

Endoscopic surgery for patients with Cushing's disease reaches comparable results for microadenomas, and probably better results for macroadenomas than microscopic surgery. This is present despite the presumed learning curve of the newer endoscopic technique, although confounding cannot be excluded. Based on this study, endoscopic surgery may thus be considered the current standard of care. Microscopic surgery can be used based on neurosurgeon's preference. Endocrinologists and neurosurgeons in pituitary centers performing the microscopic technique should at least consider referring Cushing's disease patients with a macroadenoma.

The experience with transsphenoidal surgery and its importance to outcomes

PURPOSE

Surgical experience is considered paramount for excellent outcome of transsphenoidal surgery (TSS). However, objective data demonstrating the surgical success in relation to the experience of pituitary surgery units or individual experience of pituitary surgeons is sparse.

METHODS

Based on literature data, we have investigated the influence of experience with TSS for pituitary adenomas on endocrinological remission rates and on operative complications. The surgical experience was assessed by calculating the number of transsphenoidal operations per year.

RESULTS

For TSS of microprolactinomas, mean remission rates were 77% in centers with < 2 operations per year for microprolactinomas, 82% with 2-4 operations, 84% with 4-6 operations, and 91% with > 6 operations. A yearly experience with more than 10 initial operations for Cushing's disease (CD) warrants a remission rate exceeding 70%. Remission rates in CD exceeding 86% have only been reported for single surgeon series. Extraordinarily high complication rates were found in some series with < 25 yearly total operations for pituitary adenomas. Major vascular complications were less than 2% and revision rates for rhinorrhea usually < 2.5% in centers performing > 25 transsphenoidal operations per year.

CONCLUSIONS

We conclude that a center with experience of > 25 transsphenoidal operations for pituitary adenomas per year provides a high likelihood of safe TSS. Surgery for CD requires a particularly high level of practice to guarantee excellent remission rates. The endocrinologist has the unique opportunity to audit the surgical success by hormone measurement and to refer patients to neurosurgeons with proven excellence.

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.

DIAGNOSIS OF ENDOCRINE DISEASE: The role of the desmopressin test in the diagnosis and follow-up of Cushing's syndrome

Desmopressin is a vasopressin analogue selective for type 2 vasopressin receptors that mediate renal water retention. In contrast to the native hormone arginine vasopressin, a well-known ACTH secretagogue, desmopressin, exerts minimal or no activity on ACTH excretion. However, in a substantial proportion of patients with ACTH-dependent Cushing's syndrome (CS), desmopressin elicits an ACTH and cortisol response, which contrasts with the minimal responses obtained in healthy subjects. The mechanism underlying this paradoxical response involves upregulation of vasopressin type 3 and/or the aberrant expression of type 2 receptors by neoplastic ACTH-producing cells. This makes desmopressin administration a suitable test enabling the distinction between neoplastic from functional (formerly termed 'pseudo-Cushing syndrome') ACTH-dependent cortisol excess. Several studies have now established an adjunctive role of desmopressin in the initial diagnostic workup of CS. Despite some early data indicating that this test may also have a role in distinguishing between Cushing's disease (CD) and ectopic ACTH secretion, subsequent studies failed to confirm this observation. The ability of the paradoxical response to desmopressin to depict the presence of neoplastic ACTH-secreting cells was also exploited in the follow-up of patients with CD undergoing surgery. Loss of the desmopressin response, performed in the early postoperative period, was a good predictor for a favorable long-term outcome. Moreover, during follow-up, reappearance of desmopressin paradoxical response was an early indicator for recurrence. In conclusion, the desmopressin test is a valid tool in both the diagnosis and follow-up of patients with CD and should be more widely applied in the workup of these patients.

Earlier post-operative hypocortisolemia may predict durable remission from Cushing's disease

CONTEXT

Achievement of hypocortisolemia following transsphenoidal surgery (TSS) for Cushing's disease (CD) is associated with successful adenoma resection. However, up to one-third of these patients recur.

OBJECTIVE

We assessed whether delay in reaching post-operative cortisol nadir may delineate patients at risk of recurrence for CD following TSS.

METHODS

A retrospective review of 257 patients who received 291 TSS procedures for CD at NIH, between 2003 and 2016. Early biochemical remission (serum cortisol nadir <5 μg/dL) was confirmed with endocrinological and clinical follow-up. Recurrence was detected by laboratory testing, clinical stigmata or medication dependence during a median follow-up of 11 months.

RESULTS

Of the 268 unique admissions, remission was recorded in 241 instances. Recurrence was observed in 9% of these cases with cortisol nadir ≤5 μg/dL and 6% of cases with cortisol nadir ≤2 μg/dL. The timing of hypocortisolemia was critical in detecting late recurrences. Morning POD-1 cortisol <3.3 μg/dL was 100% sensitive in predicting durable remission and morning POD-3 cortisol ≥18.5 μg/dL was 98.6% specific in predicting remote recurrence. AUROC analysis revealed that hypocortisolemia ≤5 µg/dL before 15 h (post-operative) had 95% sensitivity and an NPV of 0.98 for durable remission. Serum cortisol level ≤2 µg/dL, when achieved before 21 h, improved sensitivity to 100%.

CONCLUSIONS

In our cohort, early, profound hypocortisolemia could be used as a clinical prediction tool for durable remission. Achievement of hypocortisolemia ≤2 µg/dL before 21 post-operative hours appeared to accurately predict durable remission in the intermediate term.

Outcome of endoscopic vs microsurgical transsphenoidal resection for Cushing's disease

INTRODUCTION

It is unclear whether the proportions of remission and the recurrence rates differ between endoscopic transsphenoidal surgery (TS) and microscopic TS in Cushing's disease (CD); thus, we conducted a systematic review and meta-analysis to evaluate studies of endoscopic TS and microscopic TS.

METHODS

We conducted a comprehensive search of PubMed to identify relevant studies. Remission and recurrence were used as outcome measures following surgical treatment of CD.

RESULTS

A total of 24 cohort studies involving 1670 adult patients were included in the comparison. Among these studies, 702 patients across 9 studies underwent endoscopic TS, and 968 patients across 15 studies underwent microscopic TS. Similar baseline characteristics were observed in both groups. There was no significant difference in remission between the two groups: 79.7% (95% CI: 73.1-85.0%) in the endoscopic group and 76.9% (95% CI: 71.3-81.6%) in the microscopic group (P = 0.485). It appears that patients who underwent endoscopic surgery experience recurrence less often than patients who underwent microscopic surgery, with recurrence proportions of 11.0% and 15.9%, respectively (P = 0.134). However, if follow-up time is taken into account, both groups had a recurrence rate of approximately 4% per person per year (95% CI: 3.1-5.4% and 3.6-5.1%, P = 0.651).

CONCLUSIONS

We found that remission proportion and recurrence rate were the same in patients who underwent endoscopic TS as in patients who underwent microscopic TS. The definition of diagnosis, remission and recurrence should always be considered in the studies assessing therapeutic efficacy in CD.

Long-term outcomes of tissue-based ACTH-antibody assay-guided transsphenoidal resection of pituitary adenomas in Cushing disease

OBJECTIVE Cushing disease is caused by a pituitary micro- or macroadenoma that hypersecretes adrenocorticotropic hormone (ACTH), resulting in hypercortisolemia. For decades, transsphenoidal resection (TSR) has been an efficacious treatment but with certain limitations, namely precise tumor localization and complete excision. The authors evaluated the novel use of a double-antibody sandwich assay for the real-time quantitation of ACTH in resected pituitary specimens with the goals of augmenting pathological diagnosis and ultimately improving long-term patient outcome. METHODS This study involved a retrospective review of records and an analysis of assay values, pathology slides, and MRI studies of patients with Cushing disease who had undergone TSR in the period from 2009 to 2014 and had at least 1 year of follow-up in coordination with an endocrinologist. In the operating room, biopsy specimens from the patients had been analyzed for tissue ACTH concentration. Additional samples were simultaneously sent for frozen-section pathological analysis. The ACTH assay performance was compared against pathology assessments of surgical tumor samples using receiver operating characteristic (ROC) analysis and against pre- and postoperative MRI studies. RESULTS Fourteen patients underwent TSR with guidance by ACTH-antibody assay and pathological assessment of 127 biopsy samples and were followed up for an average of 3 years. The ACTH threshold for discriminating adenomatous from normal tissue was 290,000 pg/mg of tissue, based on jointly maximized sensitivity (95.0%) and specificity (71.3%). Lateralization discordance between preoperative MRI studies and surgical visualization was noted in 3 patients, confirming the impression that MRI alone may not achieve optimal localization. A majority of the patients (85.7%) attained long-term disease remission based on urinary free cortisol levels, plasma cortisol levels, and long-term corticosteroid therapy. Comparisons of patient-months of remission and treatment failure showed that the remission rate in the study sample statistically exceeds the rate in historical controls (71.9%; p = 0.0007, Fisher's exact test). Long-term unexpected hormonal deficiencies were statistically similar between study patients (29%) and those in a meta-analysis (25%; p = 0.7596, Fisher's exact test). CONCLUSIONS These preliminary findings reflect the promising potential of tissue-based ACTH-antibody-guided assay for improving the cure rates of Cushing disease patients undergoing TSR. Further studies with larger sample sizes, further refinements of assay interpretation, and longer-term follow-ups are needed.

POSTSURGICAL RECURRENT CUSHING DISEASE: CLINICAL BENEFIT OF EARLY INTERVENTION IN PATIENTS WITH NORMAL URINARY FREE CORTISOL

OBJECTIVE

To assess the performance of biochemical markers in the detection of recurrent Cushing disease (CD), as well as the potential benefit of early intervention in recurrent CD patients with elevated late-night salivary cortisol (LNSC) and normal urinary free cortisol (UFC).

METHODS

The design was a single-center, retrospective chart review. Patients treated by the authors from 2008-2013 were included. Recurrence was defined by postsurgical remission of CD with subsequent abnormal LNSC, UFC, or dexamethasone suppression test (DST).

RESULTS

We identified 15 patients with postsurgical recurrent CD after initial remission; all but one underwent testing with LNSC, DST, and UFC. Although 12 of 15 patients had normal UFC at time of recurrence, DST was abnormal in 11 of 15, and all 14 patients with LNSC results had ≥1 elevated measurement. Nine patients (7 with normal UFC) showed radiologic evidence of a pituitary tumor at time of recurrence. Among the 14 patients with available follow-up data, 12 have demonstrated significant improvement since receiving treatment. Five patients underwent repeat pituitary surgery and 4 achieved clinical and biochemical remission. Eight patients received mifepristone or cabergoline, and 6 showed clinical and/or biochemical improvement. Three patients (2 with prior mifepristone) underwent bilateral adrenalectomy and 2 demonstrated significant clinical improvements.

CONCLUSION

LNSC is more sensitive than UFC or DST for detection of CD recurrence. Prompt intervention when LNSC is elevated, despite normal UFC, may yield significant clinical benefit for many patients with CD. Early treatment for patients with recurrent CD should be prospectively evaluated, utilizing LNSC elevation as an early biochemical marker.

ABBREVIATIONS

ACTH = adrenocorticotropic hormone CD = Cushing disease CS = Cushing syndrome CV = coefficient of variation DST = dexamethasone suppression test IPSS = inferior petrosal sinus sampling LNSC = late-night salivary cortisol QoL = quality of life TSS = transsphenoidal adenoma resection UFC = urinary free cortisol.

Cushing's disease: pathobiology, diagnosis, and management

Cushing's disease (CD) is the result of excess secretion of adrenocorticotropic hormone (ACTH) by a benign monoclonal pituitary adenoma. The excessive secretion of ACTH stimulates secretion of cortisol by the adrenal glands, resulting in supraphysiological levels of circulating cortisol. The pathophysiological levels of cortisol are associated with hypertension, diabetes, obesity, and early death. Successful resection of the CD-associated ACTH-secreting pituitary adenoma is the treatment of choice and results in immediate biochemical remission with preservation of pituitary function. Accurate and early identification of CD is critical for effective surgical management and optimal prognosis. The authors review the current pathophysiological principles, diagnostic methods, and management of CD.

Postoperative follow-up of Cushing's disease using cortisol, desmopressin and coupled dexamethasone-desmopressin tests: a head-to-head comparison

OBJECTIVE

Predicting the outcome of patients operated on for Cushing's disease (CD) is a challenging task. Our objective was to assess the accuracy of immediate postsurgical plasma cortisol, desmopressin test and the coupled dexamethasone-desmopressin test (CDDT) as predictors of outcome.

DESIGN AND PATIENTS

Sixty-seven patients with initial remission and a minimal postsurgical follow-up greater than 18 months were included in this retrospective bicentre study.

MEASUREMENTS

Follow-up included 3-6 months followed by yearly 24-h urinary-free cortisol, ACTH and cortisol plasmatic levels, a 1-mg overnight dexamethasone suppression test (1-mg DST), desmopressin test and the CDDT. ROC curves were performed to define the optimal threshold of immediate postsurgical cortisol level and 3- to 6-month desmopressin test and CDDT, as predictors of final outcome in comparison with classical biological markers of recurrence.

RESULTS

Eleven patients presented recurrence. The patient's median follow-up was 52 months (range, 18-180). As early predictors of outcome, immediate postsurgical plasma cortisol level <35 nmol/l predicted the lack of recurrence with 93% negative predictive value (NPV), whereas predictive positive value (PPV) was 25%. During the follow-up, the CDDT was more precise than the desmopressin test in predicting the lack of recurrence (100% NPV) when performed in the first 3 years after surgery. Positivity of the CDDT was defined based on ROC curves by ACTH and cortisol increments >50%. The CDDT was highly reproducible, as the same response was observed every year in 91% of the patients.

CONCLUSIONS

Adding the CDDT the first 3 years after surgery to immediate postsurgical cortisol evaluation should allow obtaining an optimal follow-up management of patients operated for Cushing's disease.

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.

Therapy of endocrine disease: outcomes in patients with Cushing's disease undergoing transsphenoidal surgery: systematic review assessing criteria used to define remission and recurrence

OBJECTIVE

A number of factors can influence the reported outcomes of transsphenoidal surgery (TSS) for Cushing's disease - including different remission and recurrence criteria, for which there is no consensus. Therefore, a comparative analysis of the best treatment options and patient management strategies is difficult. In this review, we investigated the clinical outcomes of initial TSS in patients with Cushing's disease based on definitions of and assessments for remission and recurrence.

METHODS

We systematically searched PubMed and identified 44 studies with clear definitions of remission and recurrence. When data were available, additional analyses by time of remission, tumor size, duration of follow-up, surgical experience, year of study publication and adverse events related to surgery were performed.

RESULTS

Data from a total of 6400 patients who received microscopic TSS were extracted and analyzed. A variety of definitions of remission and recurrence of Cushing's disease after initial microscopic TSS was used, giving broad ranges of remission (42.0-96.6%; median, 77.9%) and recurrence (0-47.4%; median, 11.5%). Better remission and recurrence outcomes were achieved for microadenomas vs macroadenomas; however, no correlations were found with other parameters, other than improved safety with longer surgical experience.

CONCLUSIONS

The variety of methodologies used in clinical evaluation of TSS for Cushing's disease strongly support the call for standardization and optimization of studies to inform clinical practice and maximize patient outcomes. Clinically significant rates of failure of initial TSS highlight the need for effective second-line treatments.

Cushing's disease: predicting long-term remission after surgical treatment

Cushing's disease (CD) is a state of excess glucocorticoid production resulting from an adrenocorticotropic hormone (ACTH)–secreting pituitary adenoma. The gold-standard treatment for CD is transsphenoidal adenomectomy. In the hands of an experienced neurosurgeon, gross-total resection is possible in the majority of ACTH-secreting pituitary adenomas, with early postoperative remission rates ranging from 67% to 95%. In contrast to the strong data in support of resection, the clinical course of postsurgical persistent or recurrent disease remains unclear. There is significant variability in recurrence rates, with reports as high as 36% with a mean time to recurrence of 15–50 months. It is therefore important to develop biochemical criteria that define postsurgical remission and that may provide prognosis for long-term recurrence. Despite the use of a number of biochemical assessments, there is debate regarding the accuracy of these tests in predicting recurrence. Here, the authors review the various biochemical criteria and assess their utility in predicting CD recurrence after resection.

Long-term remission and recurrence rate in a cohort of Cushing's disease: the need for long-term follow-up

OBJECTIVE

Transsphenoidal surgery is the procedure of choice in Cushing disease (CD), with immediate post-operative remission rates ranging between 59 and 94% and recurrence rates between 3 and 46%, both depending upon the definition criteria and the duration of the follow-up. Our aim was to assess the rate of remission, recurrence and persistence of the disease after the first treatment and to identify predictors of remission in the CD population of our center.

METHODS

Retrospective cohort study of the patients diagnosed of CD and with follow-up in our center between 1974 and 2011. We analyzed 41 patients (35 women and 6 men) with a mean age at diagnosis of 34 ± 13 years. The mean follow-up was 14 ± 10 years (range 1-37 years) and the median of follow-up period was 6.68 years.

RESULTS

Thirty-five (85.4%) patients underwent transsphenoidal surgery as first treatment option. Histopathological evidence of a pituitary adenoma was registered in 17 (48.5%) patients. Thirty-two (78%) patients achieved disease remission after the first treatment, 21 (65.6%) of them presented disease recurrence. Persistent disease was observed in 9 (22%) patients. Twelve (29.3%) subjects developed post-surgical adrenal insufficiency, 7 of which (70%) achieved stable remission. Two parameters were found to be significant predictors of remission after the first treatment: age at disease diagnosis and the development of adrenal insufficiency (cortisol <3 μg/dl) in the immediate post-operative state.

CONCLUSIONS

We report a high recurrence rate, at least partially attributable to the long follow-up time. Early post-surgery adrenal insufficiency predicts remission. Hypopituitarism was also very prevalent, and strongly associated with radiotherapy. These results lead us to the conclusion that CD needs a life-long strict follow-up.

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.

Budget impact of pasireotide for the treatment of Cushing's disease, a rare endocrine disorder associated with considerable comorbidities

OBJECTIVES

Cushing's disease (CD) is a rare condition with a prevalence of roughly 39 cases per million in the general population. Healthcare costs are substantial for CD patients with either untreated or inadequately controlled disease. This study assesses the 3-year budget impact of pasireotide on a US managed care health plan following pasireotide (Signifor) availability.

METHODS

Two scenarios were evaluated to understand the differences in costs associated with the introduction of pasireotide. The first scenario evaluates the budget impact of pasireotide from the perspective of an entire health plan (total budget impact) and the second from the perspective of the pharmacy budget (pharmacy budget impact). Both scenarios evaluate the annual incremental budget impact with and without pasireotide. Scenario 1 includes costs for medical procedures, drug therapies, monitoring, surgical complications, comorbidities for patients with controlled or uncontrolled CD, and adverse events. Procedures include transsphenoidal surgery, bilateral adrenalectomy, radiotherapy and radiosurgery. Drugs include pasireotide (indicated for CD), mifepristone (indicated to control hyperglycemia secondary to hypercortisolism in patients with Cushing's syndrome) as well as several off-label treatments (ketoconazole, cabergoline, mitotane). Scenario 2 considers costs solely from the perspective of a health plan pharmacy. Costs are in $2013.

RESULTS

The estimated total budget impact is $0.0115 per-member per-month (PMPM) in the first year following FDA approval, $0.0184 in the second year, and $0.0194 in the third year. Introduction of pasireotide is expected to increase the pharmacy budget by $0.0257 PMPM in the first year, $0.0363 in the second year, and $0.0360 in the third year.

LIMITATIONS

Model inputs rely on the small body of literature available for Cushing's disease.

CONCLUSIONS

Cushing's disease is severe disease with debilitating comorbidities and substantial healthcare costs when untreated or inadequately controlled. The inclusion of pasireotide in a health plan formulary appears to have only a small impact on the total health plan or pharmacy budget.

Increased long-term remission after adequate medical cortisol suppression therapy as presurgical treatment in Cushing's disease

OBJECTIVE

In the last decade, pre-operative medical cortisol suppression therapy has frequently been used in Cushing's disease to normalize cortisol concentrations pre-operatively. Our aim was to assess the efficacy of presurgical medical cortisol suppression therapy in Cushing's disease.

DESIGN AND METHODS

We retrospectively assessed the medical files of all patients with Cushing's disease that received presurgical cortisol suppression therapy with ketoconazole or metyrapone and underwent subsequent transsphenoidal surgery between 1990 and 2010 at our centre. We retrieved the pretreatment regimen, adequacy of pretreatment, early postoperative serum cortisol levels, adverse effects and long-term remission status.

RESULTS

Nineteen of 33 patients (58%) obtained long-term remission after pituitary surgery without additional postoperative therapy. Thirteen of 16 patients with adequate presurgical cortisol suppression therapy had postoperative cortisol concentrations <50 nmol/l. The 16 patients with adequate presurgical cortisol suppression had a higher long-term remission rate after primary surgery compared with the 13 patients with borderline or inadequate pretreatment (81% vs 38%; P < 0·05).

CONCLUSIONS

Adequate presurgical cortisol suppression treatment with ketoconazole or metyrapone in Cushing's disease seems to be associated with suppressed postoperative cortisol concentrations and an increased long-term remission rate.

Impact of technique on cushing disease outcome using strict remission criteria

BACKGROUND

Cushing disease (CD) constitutes a challenging condition for the pituitary surgeon. Given the variety of factors affecting outcomes in CD, it is uncertain whether the newer endoscopic technique improves the results of surgery.

METHODS

A review was conducted of CD cases at our institution between 2000 and 2010. Analysis was done to: determine if surgical technique had an effect on outcome, identify the predictors of outcome and provide details of failed cases. Remission was defined as normal postoperative 24-hour urinary free cortisol (24-h UFC), suppression of morning serum cortisol to <50 nmol/L after 1mg of dexamethasone or being dependent on steroid replacement.

RESULTS

Forty-two patients met our inclusion criteria. Average follow-up period was 33 months. There were 15 macroadenomas and 27 microadenomas. Seventeen patients had an endoscopic transsphenoidal surgery and twenty-five patients had a microscopic transsphenoidal procedure. Long-term overall remission was achieved in 26 (62%) patients. There was no significant difference in remission rates between the two techniques (p value 0.757). Patient's subjective symptomatic improvement and drop of morning serum cortisol in the postoperative period to less than 100 nmol/L correlated with long-term remission (p value 0.0031 and 0.0101, respectively) while repeat surgery was the only predictor of the lack of postoperative remission (p value 0.0008).

CONCLUSIONS

Revision surgery predicted poor remission rate for CD. Within the power of our study size, there was no difference in outcome between the endoscopic and microscopic approaches. Surgical outcomes should be reviewed in association with remission criteria used in a study.

Remission rate after transsphenoidal surgery in patients with pathologically confirmed Cushing's disease, the role of cortisol, ACTH assessment and immediate reoperation: a large single center experience

Postoperative serum cortisol is used as an indicator of Cushing's disease (CD) remission following transsphenoidal surgery (TSS) and guides (controversially) the need for immediate adjuvant treatment for CD. We investigated postoperative cortisol and adrenocorticotropic hormone (ACTH) levels as predictors of remission/recurrence in CD in a large retrospective cohort of patients with pathologically confirmed CD, over 6 years at a single institution. Midnight and morning cortisol, and ACTH at 24-48 h postoperatively (>24 h after last hydrocortisone dose) were measured. Remission was defined as normal 24-h urine free cortisol, normal midnight salivary cortisol, a normal dexamethasone-corticotropin releasing hormone (CRH) test or continued need for hydrocortisone, assessed periodically. Statistical analysis was performed using PASW 18. Follow up data was available for 52 patients (38 females and 14 males), median follow up was 16.5 month (range 2-143 months), median age was 45 years (range 21-72 years), 28 tumors were microadenomas and 16 were macroadenomas, and in eight cases no tumor was observed on magnetic resonance imaging. No patient with postoperative cortisol levels >10 mcg/dl were found to be in remission. Ten of the 52 patients with cortisol >10 mcg/dl by postoperative day 1-2 underwent a second TSS within 7 days. Forty-three patients (82.7%) achieved CD remission (36 after one TSS and 7 after a second early TSS) and six patients suffered disease recurrence (mean 39.2 ± 52.4 months). An immediate second TSS induced additional hormonal deficiencies (diabetes insipidus) in three patients with no surgical complications. Persistent disease was noted in nine patients despite three patients having an immediate second TSS. Positive predictive value for remission of cortisol <2 mcg/dl and ACTH <5 pg/ml was 100%. Cortisol and ACTH levels (at all postoperative time points and at 2 months) were correlated (r = 0.37, P < 0.001). Nadir serum cortisol of ≤2 mcg/dl and ACTH <5 pg/ml predicted remission (P < 0.005), but no level predicted lack of recurrence. Immediate postoperative ACTH/cortisol did not predict length of remission. No patients with postoperative cortisol >10 mcg/dl were observed to have delayed remission; all required additional treatment. There was no significant difference in age, body mass index, tumor size and length of follow-up between postoperative cortisol groups: cortisol ≤2 mcg/dl, cortisol >5 mcg/dl and cortisol >10 mcg/dl. Immediate postoperative cortisol levels should routinely be obtained in CD patients post TSS, until better tools to identify early remission are available. Immediate repeat TSS could be beneficial in patients with cortisol >10 mcg/dl and positive CD pathology: our combined (micro- and macroadenomas) remission rate with this approach was 82.7%. ACTH measurements correlate well with cortisol. However, because no single cortisol or ACTH cutoff value excludes all recurrences, patients require long-term clinical and biochemical follow-up. Further research is needed in this area.

Early promising results for the endoscopic surgical treatment of Cushing's disease

High levels of endogenous cortisol due to Cushing's disease cause significant mortality and morbidity. Treatment of Cushing's disease is challenging. For many years, transsphenoidal microsurgical resection of the adenoma has been the treatment of choice. However, recently, neuroendoscope has taken its place in the neurosurgeon's armamentarium, and the endoscopic transsphenoidal resection of pituitary tumors has become a familiar approach. Our aim was to present the results of pure endoscopic surgery in the treatment of corticotropinomas for comparison with the results of previous endoscopic and microsurgical series. We present a retrospective analysis of 90 patients with diagnosis of Cushing's disease who were operated between 2006 and 2012. Among 90 patients, a total of 81 (90.0 %) had a remission (28 out of 29 macroadenomas (96.6 %) and 53 out of 61 microadenoma patients (86.9 %)). Of note is that 66 out of 69 (95.7 %) primary patients (i.e., those who were operated in our center) and 15 out of 21 (71.4 %) patients previously operated in other centers reached a hypo/eucortisolemic state. A remission rate comparable with previous endoscopic series was achieved. In nine patients, it was not possible to achieve remission at all. On the other hand, only four of our cases (5.6 %) had a recurrence, and with reoperation, all of these patients entered a re-remission. To our knowledge, our series is the largest series studying endoscopically operated adrenocorticotropic hormone-secreting adenomas. Our results suggest that the endoscopic approach has opened a new avenue in the treatment of Cushing's disease, previously a therapeutic challenge for both the clinician and the neurosurgeon. Endoscopic approach in the treatment of Cushing's disease is clearly better for patients because of its low morbidity rates and short duration of hospital stay. On the other hand, long-term follow-up of our patients will show whether these favorable observations will persist.

A new therapeutic approach in the medical treatment of Cushing's syndrome: glucocorticoid receptor blockade with mifepristone

OBJECTIVE

Cushing's syndrome (CS) is a serious endocrine disorder caused by prolonged exposure to high cortisol levels. Initial treatment of this condition is dependent upon the cause, but is generally surgical. For patients whose hypercortisolism is not cured by surgery, medical therapy is often required. Drugs that have typically been used for CS medical therapy act by decreasing cortisol levels. Mifepristone is a glucocorticoid receptor antagonist now available for use in patients with CS. Unlike other agents, mifepristone does not decrease cortisol levels, but directly antagonizes its effects. Our objective is to review the pharmacology and clinical use of this novel agent and to discuss detailed guidance on the management of CS patients treated with mifepristone.

METHODS

We review the literature regarding mifepristone use in CS and recently published clinical trial data. Detailed information related to clinical assessment of mifepristone use, potential drug interactions, drug initiation and dose titration, and monitoring of drug tolerability are provided.

RESULTS

Clinical trial data have shown that mifepristone improves glycemic control and blood pressure, causes weight loss and a decrease in waist circumference, lessens depression, and improves overall wellbeing. However, adverse effects include adrenal insufficiency, hypokalemia, and endometrial thickening with vaginal bleeding. These findings are supported by the earlier literature case reports.

CONCLUSION

This article provides a review of the pharmacology and clinical use of mifepristone in Cushing's syndrome, as well as detailed guidance on the management of patients treated with this novel agent.

Endoscopic transsphenoidal pituitary surgery: a good and safe primary treatment option for Cushing's disease, even in case of macroadenomas or invasive adenomas

CONTEXT

Although the endoscopic technique of transsphenoidal pituitary surgery (TS) has been widely adopted, reports on its results in Cushing's disease (CD) are still scarce and no studies have investigated long-term recurrence rates. This is the largest endoscopic series published till now.

OBJECTIVE

To gain insight into the role of endoscopic TS as a primary treatment option for CD, especially in patients with magnetic resonance imaging (MRI)-negative CD and (invasive) macroadenomas.

DESIGN

Retrospective cohort study.

PATIENTS AND METHODS

The medical records of 86 patients with CD who underwent endoscopic TS were examined. Data on preoperative and postoperative evaluation, perioperative complications, and follow-up were collected. Remission was defined as disappearance of clinical symptoms with a fasting plasma cortisol level ≤ 50 nmol/l either basal or after 1 mg dexamethasone.

RESULTS

The remission rate in different adenoma subclasses varied significantly: 60% in MRI-negative CD (n=20), 83% in microadenomas (n=35), 94% in noninvasive macroadenomas (n=16), and 40% in macroadenomas that invaded the cavernous sinus (n=15). The recurrence rate was 16% after 71 ± 39 months of follow-up (mean ± S.D., range 10-165 months).

CONCLUSIONS

Endoscopic TS is a safe and effective treatment for all patients with CD. Recurrence rates after endoscopic TS are comparable with those reported for microscopic TS. Our data suggest that in patients with noninvasive and invasive macroadenomas, the endoscopic technique of TS should be the treatment of choice as remission rates seem to be higher than those reported for microscopic TS, although no comparative study has been performed.

Mifepristone: is there a place in the treatment of Cushing's disease?

The purpose was to review the use of mifepristone in the treatment of Cushing's syndrome (CS) in the context of other recently published studies. We review the use of mifepristone, as published in the recent Study of the Efficacy and Safety of Mifepristone in the Treatment of Endogenous Cushing's Syndrome (SEISMIC). We also review the multiple case reports and case series of mifepristone use in CS. A review of other medications used in the treatment of Cushing's disease (CD), including pasireotide and cabergoline also provides context for the discussion of the role of mifepristone in the treatment of CD. The results show that the treatment of CD has been primarily surgical with medical therapy reserved for adjuvant therapy when primary treatment fails or other therapies require time for optimal efficacy. Two recent large prospective studies, using pasireotide and mifepristone provide new clinical insights to the medical treatment of CD in particular. Mifepristone has been used to treat excessive cortisol production by blocking the action of cortisol at the level of the glucocorticoid receptor. Until recently, the majority of clinical experience with mifepristone on the treatment of excess cortisol was derived from case reports and small case series. Based on the SEISMIC study, mifepristone was FDA approved for hyperglycemia associated with CS. In conclusion the role of mifepristone in the treatment of CD remains one of adjuvant therapy. Its place among other choices for medical therapy has yet to be firmly established and an evidenced-based approach toward the use of novel medications in the treatment of CD has not been made. Selection of medication depends on drug approval and availability in individual countries and requires cautious assessment of potential adverse effects, consideration of patient comorbidities, and efficacy.

Clinical factors involved in the recurrence of pituitary adenomas after surgical remission: a structured review and meta-analysis

To study the currently available data of recurrence rates of functioning and nonfunctioning pituitary adenomas following surgical cure and to analyze associated predisposing factors, which are not well established. A systematic literature search was conducted using Medline, Embase, Web of Science and the Cochran Library for studies reporting data on recurrence of pituitary adenoma after surgery, in nonfunctioning adenoma (NF), prolactinoma (PRL) acromegaly (ACRO) and Cushing's disease (CUSH). Of 557 initially retrieved potential relevant studies 143 were selected. Recurrence in NFA was defined as reappearance of tumor on MRI or CT. Increase of hormone levels above normal limits as set by the authors after initial remission was used to indicate recurrence in the functioning tumor types. Remission percentage was lowest in NFA compared with other tumor types (P < 0.001). Surgery-related hypopituitarism was more frequent in CUSH than in the other tumors (P < 0.001). Recurrence, expressed as percentage of the cured population or as ratio of recurrence and total patient years of follow-up was highest in PRL (P < 0.001). The remission percentage did not improve over 3 decades of publications, but there was a modest decrease in recurrence rate (P = 0.04). Recurrences peaked between 1 and 5 years after surgery. Most of the studies with a sufficient number of recurrences did not apply multivariate statistics, and mentioned at best associated factors. Age, gender, tumor size and invasion were generally unrelated to recurrence. For functioning adenomas a low postoperative hormone concentration was a prognostically favorable factor. In NFA no specific factor predicted recurrence. Recurrence rate differs between pituitary adenomas, being highest in patients with prolactinoma, with the highest incidence of recurrence between 1 and 5 years after surgery in all adenomas. Patients with NFA have a lower chance of remission than patients with functioning adenomas. The postoperative basal hormone level is the most important predictor for recurrence in functioning adenomas, while in NFA no single convincing factor could be identified.

Rapid decrease in adrenal responsiveness to ACTH stimulation after successful pituitary surgery in patients with Cushing's disease

OBJECTIVE

The aim of this study was to investigate the effects of transsphenoidal surgery (TS) on the adrenal sensitivity to ACTH (adrenocorticotropin) stimulation in patients with Cushing's disease (CD).

METHODS

We measured the cortisol response to 1 μg synthetic ACTH (1-24) 6 days after pituitary surgery in 45 patients with CD. Mean follow-up period was 56·5 months (SE 4·7).

RESULTS

In 24 of 28 patients in sustained remission after pituitary surgery, peak cortisol concentrations below 774 nm (28·0 μg/dl) were recorded after stimulation with 1 μg synthetic ACTH (86%). Two patients with recurrent disease after initial remission (late relapse) also showed ACTH-stimulated peak cortisol levels below 774 nM. Fourteen of 15 patients with persistent CD after surgery (early failure) showed absolute peak cortisol levels >774 nm in response to ACTH stimulation.

CONCLUSION

Patients in remission after pituitary surgery for CD showed a rapid decrease of adrenal responsiveness to exogenous ACTH stimulation. This phenomenon may be explained by ACTH-receptor down-regulation in the adrenal cortex after complete removal of the pituitary corticotroph adenoma. In our study, the postoperative low-dose ACTH stimulation test had a sensitivity of 93% and a specificity of 87% in predicting immediate remission of CD after pituitary surgery.