Postoperative metyrapone test in the early assessment of outcome of pituitary surgery for Cushing's disease

Early Morning Cortisol Level as a Predictive Factor for Long-Term Glucocorticoid Replacement After Pituitary Surgery: A Systematic Review and Meta-Analysis

BACKGROUND

A reliable strategy for predicting long-term adrenal insufficiency after pituitary surgery can reduce the risk of glucocorticoid overexposure or missing patients with pituitary insufficiency. For this purpose, we aimed to assess the predictive value of early postoperative morning serum cortisol level for the detection of hypothalamic-pituitary-adrenal axis dysfunction in patients who underwent pituitary surgery.

METHODS

A Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)-based systematic review was conducted to include articles investigating morning blood cortisol levels after pituitary surgery for lesions of the pituitary gland as a determinant for administration of long-term supplemental glucocorticoids. Bayesian statistics were used to pool the sensitivity and specificity rates. Sensitivity and specificity were also determined for each potential cortisol level on postoperative day (POD) 1 and POD 2.

RESULTS

The study included 17 articles encompassing 1648 patients. Morning cortisol levels on POD 1 and POD 2 showed pooled sensitivity rates of 86.4% and 86.6% and pooled specificity rates of 73.1% and 78.2%, respectively, for predicting long-term glucocorticoid replacement after surgery. A cortisol level of 2.1 μg/dL showed the highest sensitivity rate (98.78%), and 22.5 μg/dL showed the highest specificity rate (72.5%) on POD 1.

CONCLUSIONS

In this review and Bayesian meta-analysis, we found that postoperative serum cortisol measurement may have high accuracy in prediction of the long-term need for glucocorticoid administration in patients who underwent pituitary surgery.

Postoperative Day 1 Morning Cortisol Value as a Biomarker to Predict Long-term Remission of Cushing Disease

CONTEXT

Recurrence of Cushing disease (CD) can occur even decades after surgery. Biomarkers to predict recurrence of CD after surgery have been studied but are inconclusive.

OBJECTIVE

The aim of our study was to identify specific biomarkers that can predict long-term remission after neurosurgery.

DESIGN

Identification of specific biomarkers to predict long-term remission of CD was performed by logistic regression analysis followed by Kaplan-Meier survival analysis, using recurrence as the dependent variable.

SETTING

A total of 260 patients with CD identified from our institutional research patient data registry search tool and from patients who presented to our longitudinal multidisciplinary clinic between May 2008 and May 2018 underwent statistical analysis.

INTERVENTIONS

Data on clinical features, neuro-imaging study, pathology, biochemistry, and treatments were collected by reviewing digital chart records.

MAIN OUTCOME MEASURE

Postoperative cortisol as a biomarker to predict long-term remission after surgical treatment for CD.

RESULTS

By logistic regression analysis, postoperative day 1 (POD1) morning (5-10 am) serum cortisol, female sex, and proliferative index had significant association with CD recurrence (odds ratio [OR] = 1.025, 95% CI: 1.002-1.048, P = .032). In contrast, the postoperative nadir cortisol (OR = 1.081, 95% CI: 0.989-1.181, P = .086), urinary free cortisol (OR = 1.032, 95% CI: 0.994-1.07, P = .098), and late night salivary cortisol (OR = 1.383, 95% CI: 0.841-2.274, P = .201) had no significant correlation with recurrence. A significant association between POD1 morning serum cortisol and long-term CD remission was verified by Kaplan-Meier analysis when using POD1 morning serum cortisol <5 μg/dL as the cut-off.

CONCLUSIONS

The POD1 morning serum cortisol level has a significant association with CD recurrence.

Adrenally Directed Medical Therapies for Cushing Syndrome

CONTEXT

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

EVIDENCE ACQUISITION

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

EVIDENCE SYNTHESIS

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

CONCLUSIONS

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

Recurrence after pituitary surgery in adult Cushing's disease: a systematic review on diagnosis and treatment

PURPOSE

Recurrence after pituitary surgery in Cushing's disease (CD) is a common problem ranging from 5% (minimum) to 50% (maximum) after initially successful surgery, respectively. In this review, we give an overview of the current literature regarding prevalence, diagnosis, and therapeutic options of recurrent CD.

METHODS

We systematically screened the literature regarding recurrent and persistent Cushing's disease using the MESH term Cushing's disease and recurrence. Of 717 results in PubMed, all manuscripts in English and German published between 1980 and April 2020 were screened. Case reports, comments, publications focusing on pediatric CD or CD in veterinary disciplines or studies with very small sample size (patient number < 10) were excluded. Also, papers on CD in pregnancy were not included in this review.

RESULTS AND CONCLUSIONS

Because of the high incidence of recurrence in CD, annual clinical and biochemical follow-up is paramount. 50% of recurrences occur during the first 50 months after first surgery. In case of recurrence, treatment options include second surgery, pituitary radiation, targeted medical therapy to control hypercortisolism, and bilateral adrenalectomy. Success rates of all these treatment options vary between 25 (some of the medical therapy) and 100% (bilateral adrenalectomy). All treatment options have specific advantages, limitations, and side effects. Therefore, treatment decisions have to be individualized according to the specific needs of the patient.

Prediction of recurrence and remission within 3 years in patients with Cushing disease after successful transnasal adenomectomy

BACKGROUND

Some laboratory and clinical features are associated with a probability of recurrence after transnasal adenomectomy for Cushing disease (CD). However, there is no consensus on a set of predictors. Rules for prediction of recurrence were not proposed earlier.

AIM

To develop prediction model of recurrence/remission after successful neurosurgical treatment for CD.

METHODS

Retrospective single-site comparative study included 349 patients (52 men and 297 women) with a verified diagnosis of CD who underwent effective endoscopic transsphenoidal adenomectomy between 2007 and 2014. Clinical and laboratory parameters were evaluated. Laboratory tests were performed using immunochemiluminescent method. Time-to-event analysis and ROC-analysis were applied. Multivariate models were developed using logistic regression and artificial neural network (ANN).

RESULTS

Postoperative cortisol and ACTH levels and their combinations cannot be used for prediction of recurrence. ANN for prediction of recurrence within 3 years after successful surgery was developed. Input variables are age, duration of the disease, MRI data on adenoma, morning postoperative levels of ACTH and cortisol, output variable is binary (recurrence/remission). Predictive value for remission is 93%, 95% CI [89%; 96%], and predictive value for recurrence is 85%, 95% CI [71%; 94%]. Web-calculator based on the model is developed and free for use.

CONCLUSION

Effective method for prediction of recurrence and long-term remission within 3 years after successful endoscopic transsphenoidal adenomectomy is proposed.

Dynamics of postoperative serum cortisol after transsphenoidal surgery for Cushing's disease: implications for immediate reoperation and remission

OBJECTIVESuccessful transsphenoidal surgery for adrenocorticotropin hormone (ACTH)-producing pituitary tumors is associated with subnormal postoperative serum cortisol levels, which may guide decisions regarding immediate reoperation. However, little is known about the detailed temporal course of changes in serum cortisol in the immediate postoperative period, and the relationship of postoperative cortisol dynamics to remission and late recurrence.METHODSA single-center retrospective cohort analysis was performed for all patients undergoing pituitary surgery from 2007 through 2015. Standardized diagnostic and treatment algorithms were applied to all patients with potential Cushing's disease (CD), including microsurgical transsphenoidal adenomectomy (TSA) by a single surgeon. All patients had serum cortisol levels drawn at 6-hour intervals for 72 hours after surgery, and were offered reoperation within 3 days for normal or supranormal postoperative cortisol levels. Primary outcomes were 6-month remission and late recurrence; secondary outcomes were persistent postoperative hypocortisolism and surgical morbidity. Discriminatory levels of postoperative serum cortisol for predicting remission were calculated at various intervals after surgery using receiver operating characteristic (ROC) curves.RESULTSAmong 89 patients diagnosed with CD, 81 underwent initial TSA for a potentially curable lesion; 23 patients (25.8%) underwent an immediate second TSA. For the entire cohort, 6-month remission was achieved in 77.8% and late recurrences occurred in 9.5%, at a mean of 43.5 months. Compared with patients with a single surgery, those with an immediate second TSA had similar rates of remission (78.3% vs 77.6%) and late recurrence (5.6% vs 11.1%). The rate of hypocortisolism for patients with 2 surgeries (12/23, 52.2%) was significantly greater than that for patients with single surgeries (13/58, 22.4%; p < 0.001). There was no difference in the incidence of CSF leaks between the first and second operations. Remission was achieved in 58 (92.1%) of 64 patients who completed the 2-surgery protocol. The temporal course of postoperative serum cortisol levels among patients varied considerably, with subnormal nadir levels < 2 μg/dl occurring between 12 hours and 66 hours. Patients achieving remission had significantly lower mean serum cortisol levels at every time point after surgery (p < 0.01). By ROC curve analysis, nadir cortisol levels < 2.1 μg/dl were predictive of 6-month remission for the entire cohort over 3 days (positive predictive value [PPV] = 94%); discriminating cortisol levels for predicting remission on postoperative day (POD) 2 were < 5.4 μg/dl (PPV = 97%), although patients with remission after postoperative cortisol levels of 2-5 μg/dl had a significantly higher rate of late recurrence.CONCLUSIONSThere is substantial variation in the temporal course of serum cortisol levels over the first 72 hours after TSA for CD, with nadir levels predictive for remission occurring as late as POD 3. Although a cortisol level of 2.1 μg/dl at any point was an accurate predictor of 6-month remission, levels less than 5.4 μg/dl on POD 2 were reasonably accurate. These data may enable decisions regarding the efficacy of an immediate second surgical procedure performed during the same hospitalization; immediate reoperation is associated with excellent remission rates and low recurrence rates in patients otherwise unlikely to achieve remission, but carries a higher risk of permanent hypocortisolism.

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.

Adrenocorticotropic hormone levels before treatment predict recurrence of Cushing's disease

BACKGROUND/PURPOSE

Cushing's disease (CD) is the most common cause of endogenous Cushing's syndrome. Transsphenoidal surgery (TSS) is the first choice of treatment. Predicting prognosis after treatment can benefit further strategies of management, but currently there is no convenient predictor. This study aims to investigate characteristic changes after treatment and to identify potential prognostic predictors.

METHODS

We retrospectively studied the records of CD patients presenting to the National Taiwan University Hospital, Taipei, Taiwan between 1992 and 2011. They were categorized according to treatment response. Clinical features and examination findings were compared between groups.

RESULTS

Forty-one patients with CD were included. The follow-up time was 0.26-19.3 years. The time interval between the onset of symptoms and diagnosis was 2.1-120.0 months. The initial remission rate of CD after the first treatment was 82.9%. Mean body mass index (BMI) was 27.4 kg/m² before treatment and 26.0 kg/m² 3 months after treatment. The patients in remission had a greater decrease in BMI after treatment and lower dehydroepiandrosterone sulfate (DHEAS) levels before treatment, compared with the recurrent group (both p < 0.05). Adrenocorticotropic hormone (ACTH) levels before treatment showed a significant positive correlation with recurrent diseases (p < 0.05).

CONCLUSION

A larger decrease in BMI after treatment and lower DHEAS levels before treatment were noted for the patients who stayed in CD remission. Higher ACTH levels before treatment predicted a recurrence of CD. These are potentially simple and practical predictors of prognosis.

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.

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.

The postoperative basal cortisol and CRH tests for prediction of long-term remission from Cushing's disease after transsphenoidal surgery

CONTEXT

Selective adenomectomy via transsphenoidal surgery induces remission of Cushing's disease (CD) in most patients. Although an undetectable postoperative serum cortisol (<2 μg/dl) has been advocated as an index of remission, there is no consensus on predictors of recurrence.

OBJECTIVE

We hypothesized that patients with subnormal cortisol (2-4.9 μg/dl) might achieve long-term remission and that postoperative responses to CRH might predict recurrence.

DESIGN, SETTING, AND PARTICIPANTS

We prospectively studied CD patients with initial remission after adenomectomy or hemihypophysectomy (n = 14). Long-term recurrence (n = 39) or remission (n = 293) was assigned by laboratory results, glucocorticoid dependence, or patient survey at a mean of 10.6 yr after surgery.

INTERVENTION AND MAIN OUTCOME MEASURES

Postoperatively, morning cortisol was measured on d 3-5, and cortisol and ACTH responses to ovine CRH were assessed around d 10.

RESULTS

Follow-up duration was median 11 yr (range 1-22.8 yr). Fewer patients achieved a cortisol nadir below 2 μg/dl (87%) than below 5 μg/dl (98%), yet recurrence rates were similar (<2 μg/dl, 9.5%; <5 μg/dl, 10.4%; 2-4.9 μg/dl, 20%; not significant). CRH-stimulated cortisol (P < 0.002) and ACTH (P = 0.04) values were higher for the recurrence than the remission group. However, no basal or stimulated ACTH or serum or urine cortisol cutoff value predicted all who later recurred.

CONCLUSIONS

A postoperative cortisol below 2 μg/dl predicts long-term remission after transsphenoidal surgery in CD. Remission in those with intermediate d 3-5 postoperative cortisol values (2-4.9 μg/dl) suggests that these patients do not require immediate reoperation. However, because no single cortisol cutoff value excludes all patients with recurrence, all require long-term clinical follow-up.

Management of Cushing disease

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

A combined dexamethasone desmopressin test as an early marker of postsurgical recurrence in Cushing's disease

CONTEXT

Recurrence of Cushing's disease (CD) after transsphenoidal surgery (TSS) occurs in about 25% of cases. Twenty percent of patients with immediate postsurgical corticotroph deficiency will present late recurrence.

OBJECTIVE

The aim of the study was to evaluate a coupled dexamethasone desmopressin test (CDDT) as a predictor of recurrence of CD.

DESIGN

We conducted a prospective bicenter study (Marseille and Grenoble, France).

PATIENTS

We studied 38 patients treated by TSS for CD with a mean follow-up of 60 months.

INTERVENTION(S)

We evaluated 24-h urinary free cortisol, ACTH, and cortisol plasmatic levels and performed low-dose dexamethasone suppression test and CDDT 3 to 6 months after surgery and then yearly.

MAIN OUTCOME MEASURES

After CDDT, ACTH ratio (ACTHr) was defined as (PeakACTH - BaseACTH)/BaseACTH. Cortisol ratio (Cortisolr) was defined as (PeakCortisol - BaseCortisol)/BaseCortisol. Basal values were observed after low-dose dexamethasone suppression test. Receiver operator characteristics curve defined ACTHr and Cortisolr giving the best sensitivity and specificity associated with recurrence.

RESULTS

Ten patients presented recurrence. ACTHr and Cortisolr were superior or equal to 0.5 in all patients with recurrence and in three of 28 patients in remission (100% sensitivity, 89% specificity). The test became positive in eight of 10 patients with recurrence 6-60 months before classical markers of hypercortisolism. Six patients with immediate postsurgical corticotroph deficiency presented recurrence. All of them presented CDDT positivity during the 3 yr after surgery, and recurrence 6 to 60 months after CDDT positivity.

CONCLUSIONS

CDDT is an early predictor of recurrence of CD and could be of particular interest in the first 3 yr after surgery, by selecting patients at high risk of recurrence despite falsely reassuring classical hormonal markers.

Role for postoperative cortisol response to desmopressin in predicting the risk for recurrent Cushing's disease

In the early postoperative period of Cushing's disease patients, desmopressin may stimulate ACTH secretion in the remnant corticotrophic tumour, but not in nontumour suppressed cells.

OBJECTIVE

The aim of this study is to evaluate the serum cortisol responses to desmopressin after pituitary surgery, establishing an optimal cut-off for absolute increment (Delta) of serum cortisol (F) suitable to predict recurrence risk.

DESIGN

Retrospective case record study.

PATIENTS

Fifty-seven Cushing's disease patients submitted to pituitary surgery and desmopressin stimulation in the early postoperative with a long-term follow-up (20-161 months) were studied.

METHODS AND MEASUREMENTS

Serum cortisol levels after desmopressin test (10 microg i.v.) 15-30 days after adenomectomy were used to determine DeltaF (absolute increment of F: F peak - F baseline). Sensitivity and specificity of DeltaF were calculated and a ROC curve was performed to establish an optimal cut-off for DeltaF to predict recurrence risk.

RESULTS

Fifteen patients had immediate postoperative failure (basal F > 165 nmol/l; 6 microg/dl) and one patient was lost during the follow-up. Forty-one patients achieved initial remission and were followed-up. Five of 11 patients who recurred had DeltaF > 193 nmol/l (7 microg/dl), but none of 30 patients who remained in prolonged remission showed DeltaF > 193 nmol/l after postoperative desmopressin stimulation.

CONCLUSIONS

Persistence of cortisol response (DeltaF > 193 nmol/l) to desmopressin in the early postoperative period can help to identify Cushing's disease patients with initial remission who present risk for later recurrence.

Criteria of cure and remission in Cushing's disease: an update

We review the clinical and biochemical criteria used for evaluation of the transsphenoidal pituitary surgery results in the treatment of Cushing's disease (CD). Firstly, we discuss the pathophysiology of the hypothalamic-pituitary-adrenal axis in normal subjects and patients with CD. Considering the series published in the last 25 years, we observed a significant variation in the remission or cure criteria, including the choice of biochemical tests, timing, threshold values to define remission, and the interference of glucocorticoid replacement or previous treatment. In this context we emphasize serum cortisol levels obtained early (from hours to 12 days) in the postoperative period without any glucocorticoid replacement or treatment. Our experience demonstrates that: (i) early cortisol < 5 to 7 µg/dl, (ii) a period of glucocorticoid dependence > 6 mo, (iii) absence of response of cortisol/ACTH to CRH or DDAVP, (iv) return of dexamethasone suppression, and circadian rhythm of cortisol are appropriate indices of remission of CD. In patients with undetectable cortisol levels early after surgery, recurrence seems to be low. Finally, although certain biochemical patterns are more suggestive of remission or surgical failure, none has been proven to be completely accurate, with recurrence observed in approximately 10 to 15% of the patients in long-term follow-up. We recommended that patients with CD should have long-term monitoring of the CRH-ACTH-cortisol axis and associated co-morbidities, especially hypopituitarism, diabetes mellitus, hypertension, cardiovascular disturbances, and osteoporosis.

Long-term remission rates after pituitary surgery for Cushing's disease: the need for long-term surveillance

OBJECTIVE

There have been a few reports on long-term remission rates after apparent early remission following pituitary surgery in the management of Cushing's disease. An undetectable postoperative serum cortisol has been regarded as the result most likely to predict long-term remission. Our objective was to assess the relapse rates in patients who underwent transsphenoidal surgery in order to determine whether undetectable cortisol following surgery was predictive of long-term remission and whether it was possible to have long-term remission when early morning cortisol was measurable but not grossly elevated. Endocrinological factors associated with late relapse were also studied.

PATIENTS

We reviewed the long-term outcome in 63 patients who had pituitary surgery for the treatment of Cushing's disease between 1979 and 2000.

MEASUREMENTS

Case notes were reviewed and the current clinical and biochemical status assessed. Our usual practice was that early after the operation, an 08:00 h serum cortisol was measured 24 h after the last dose of hydrocortisone. This was followed by a formal low-dose dexamethasone suppression test. Current clinical status and recent 24-h urinary free cortisol values were used as an index of activity of the Cushing's disease. If there was evidence suggesting relapse, a low-dose dexamethasone suppression test was performed. In many patients, sequential collections of early morning urine specimens for urinary cortisol to creatinine ratio were also performed in an attempt to diagnose cyclical and intermittent forms of recurrent hypercortisolism. We did this if there was conflicting endocrine data, or if patients were slow to lose abnormal clinical features.

RESULTS

Mean age at diagnosis was 40.3 years (range 14-70 years). Mean follow-up up time was 9.6 years (range 1-21 years). Forty-five patients (9 males/36 females) achieved apparent remission immediately after surgery and were subsequently studied long term. Of these 45 patients, four have subsequently died while in remission from hypercortisolism. Ten of the remaining 41 patients have relapsed. Of those 10, six demonstrated definite cyclical cortisol secretion. Two of the 10 had undetectable basal serum cortisol levels in the immediate postoperative period. Thirty-one patients are still alive and in remission. Fourteen (45%) of the 31 who remained in remission had detectable serum cortisol levels (> 50 nmol/l) immediately postoperatively, and remain in remission after a mean of 8.8 years. Our relapse rate was therefore 10/45 (22%), after a mean follow-up time of 9.6 years, with mean time to relapse 5.3 years.

CONCLUSIONS

The overall remission rate of 56% (35/63) at 9.6 years follow-up is disappointing and merits some re-appraisal of the widely accepted principle that pituitary surgery must be the initial treatment of choice in pituitary-dependent Cushing's syndrome. Following pituitary surgery, careful ongoing expert endocrine assessment is mandatory as the incidence of relapse increases with time and also with increasing rigour of the endocrine evaluation. A significant number of our patients were shown to have relapsed with a cyclical form of hypercortisolism.

Pituitary surgery and postoperative management in Cushing's disease

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

Recurrence of Cushing's disease preceded by the reappearance of ACTH and cortisol responses to desmopressin test

At present no single test is considered of absolute value in identifying patients successfully operated for Cushing's disease who are at risk for recurrence. The present report describes the first two patients in whom ACTH/cortisol abnormal responses to desmopressin disappeared after cure and then clearly reappeared during long-term follow-up several months before the clinical and hormonal features of hypercortisolism became manifest. The case histories of 2 young women are reported. The diagnosis of Cushing's disease was made on the basis of clinical features and standard hormonal criteria. Both patients, showing abnormal ACTH/cortisol rises after desmopressin test, underwent pituitary adenomectomy by transsphenoidal surgery and after operation plasma ACTH and serum cortisol levels were 0.2 and 0.4 pmol/l and 56 and 32 nmol/l, respectively. During the follow-up both patients underwent desmopressin (10 microg iv), ovine CRH (1 microg/kg iv) and 1 mg dexamethasone tests at 1, 6, 12, 24 months after surgery. In these two cases the ACTH/cortisol response to desmopressin normalized following pituitary adenomectomy, concomitantly with the normalization of all the other clinical and hormonal parameters. Subsequently abnormal rises after the synthetic AVP analogue administration appeared: paradoxical ACTH/cortisol increments after desmopressin occurred 24 and 6 months before any other hormonal or clinical sign of recurrence of hypercortisolism. As desmopressin may be able to stimulate ACTH/cortisol release in Cushing's disease, but not in normal subjects, we suggest that it can have a role in early identifying successfully operated Cushing's patients at risk for recurrence.

Undetectable postoperative cortisol does not always predict long-term remission in Cushing's disease: a single centre audit

OBJECTIVE

An undetectable postoperative serum cortisol has been regarded as a definition of cure in Cushing's disease. However, we noted disease recurrence amongst patients with Cushing's disease despite undetectable postoperative cortisol levels, and this led us to audit our data. We have also previously assessed surgical outcome for acromegaly and microprolactinoma for a single surgeon. The aims of this study were two-fold: (i) to investigate the treatment and surgical outcome of patients with Cushing's disease. In particular, we wished to compare the data with outcome for other pituitary tumours in our centre; and (ii) to determine whether undetectable cortisol following surgery is predictive of long-term cure for Cushing's disease.

PATIENTS AND METHODS

We performed a retrospective audit of 97 patients; mean age 39.1 (range: 14-82) years, 78/97 (80.4%) female, mean follow-up 92 months (range: 6 months to 29 years), with Cushing's disease seen in our unit between 1969 and 1998. We documented diagnostic investigation, immediate surgical outcome and disease recurrence in these patients.

RESULTS

All patients had elevated urinary free cortisol (mean 1270.6 nmol/l, range: 327-3245 nmol/l). In total, 95.5% of patients did not suppress with low-dose dexamethasone suppression testing. Hypokalaemia (K < 3.2 mmol/l) was present in 15.6% of patients; 17.5% of patients did not show cortisol suppression with high-dose dexamethasone and 15.8% of patients did not show an ACTH rise of > 50% following corticotrophic releasing hormone (CRH) administration. There was no significant (> 3) gradient in ACTH or cortisol following CRH during inferior petrosal sinus sampling in 27.3% of patients who had the test. A pituitary tumour was demonstrated on imaging in 55.8% of patients; 10.3% were macroadenomas. Mortality rate following trans-sphenoidal surgery was 1%. Following surgery, the immediate postoperative remission rate (undetectable postoperative cortisol) was 68.5%. However, 11.5% of these patients developed disease recurrence during a mean follow-up period of 36.3 months. Considering microadenomas, Cushing's disease patients had an immediate postoperative remission rate of 63.2% which is significantly lower (P < 0.05) compared to a remission rate of 91.1% in acromegaly. Additionally, new postoperative gonadotrophin deficiency (13.9%) and TSH deficiency (25.8%) was higher in patients with Cushing's disease compared to patients with acromegaly or microprolactinoma. Immediate postoperative remission rates improved from 50% in the first decade of a surgeon's career to consistently above 60% in the second and third decades, demonstrating a trend which may be attributed to surgical experience.

CONCLUSIONS

(i) Despite strict criteria for immediate postoperative remission and recurrence, undetectable postoperative cortisol is not always predictive of long-term remission. (ii) Despite an aggressive surgical approach, immediate postoperative remission rates for Cushing's disease are lower compared to other microadenomas. The development of new pituitary hormonal deficiency following surgery is also commoner than that seen amongst other microadenomas. These data have important implications for the follow-up of patients with Cushing's disease.