Effectiveness of medical treatment for Cushing's syndrome: a systematic review and meta-analysis.

PURPOSE: To systematically review the effectiveness of medical treatment for Cushing's syndrome in clinical practice, regarding cortisol secretion, clinical symptom improvement, and quality of life. To assess the occurrence of side effects of these medical therapies. METHODS: Eight electronic databases were searched in March 2017 to identify potentially relevant articles. Randomized controlled trials and cohort studies assessing the effectiveness of medical treatment in patients with Cushing's syndrome, were eligible. Pooled proportions were reported including 95% confidence intervals. RESULTS: We included 35 articles with in total 1520 patients in this meta-analysis. Most included patients had Cushing's disease. Pooled reported percentage of patients with normalization of cortisol ranged from 35.7% for cabergoline to 81.8% for mitotane in Cushing's disease. Patients using medication monotherapy showed a lower percentage of cortisol normalization compared to use of multiple medical agents (49.4 vs. 65.7%); this was even higher for patients with concurrent or previous radiotherapy (83.6%). Mild side effects were reported in 39.9%, and severe side effects were seen in 15.2% of patients after medical treatment. No meta-analyses were performed for clinical symptom improvement or quality of life due to lack of sufficient data. CONCLUSIONS: This meta-analysis shows that medication induces cortisol normalization effectively in a large percentage of patients. Medical treatment for Cushing's disease patients is thus a reasonable option in case of a contraindication for surgery, a recurrence, or in patients choosing not to have surgery. When experiencing side effects or no treatment effect, an alternate medical therapy or combination therapy can be considered.

Update on Hypercortisolism Therapy.

Treating Cushing's syndrome is very challenging and should be tailored to the patient. Surgery is considered the gold standard treatment for both pituitary adrenocorticotropic hormone (ACTH)-secreting adenomas, ectopic ACTH-secreting tumors and adrenal tumors, as the chance to be successful is high, especially for adrenal tumors, when performed in specialized centers by expert surgeons. Pituitary radiotherapy represents a second-line treatment in patients not cured with surgery, or when medical treatment is not suitable/efficacious, although the rate of cure is largely variable and achieved only in the long term, and is associated with the risk of developing secondary hypopituitarism. Several drugs, acting at the pituitary, adrenal or peripheral tissue level, are available. Medical treatment is indicated as second-line therapy for patients unsuccessfully treated with pituitary surgery, or in those awaiting radiotherapy to become effective, or prior to adrenalectomy, and as the first-line approach to prepare patients for surgery, especially those with severe comorbidities, or in those not suitable/refusing surgery. The success rate of medical therapy is variable, depending on the cause and severity of hypercortisolism, and is often associated with important side effects.

Radiation-induced opticochiasmatic glioblastoma multiforme following conventional radiotherapy for Cushing's disease.

We report the rare occurrence of an opticochiasmatic glioblastoma multiforme 6 years following conventional radiotherapy for Cushing's disease. This article highlights the risks of collateral damage to the optic apparatus when irradiating the sellar region.

Von Hippel Lindau disease with metastatic pancreatic neuroendocrine tumor causing ectopic Cushing's syndrome.

We present a 39-year-old woman who was previously diagnosed with Von Hippel Lindau Disease (VHLD). She had surgery and radiotherapy for cranial hemangioblastoma (HA) 11 years ago and had unilateral adrenalectomy for pheochromocytoma in another hospital 6 month prior to her admission to our center. Moon face, buffalo hump, central obesity, progressive weight gain and menstrual irregularities persisted after adrenalectomy. Her laboratory results were consistent with ectopic Cushing's syndrome (ECS). A pancreatic solid mass with a nodule on the left lung were revealed upon computed tomography. In addition, Gallium-68 Somatostatin Receptor PET confirmed the pancreatic involvement and demonstrated additional lesions on the left lung and in the aortocaval lymphatic system on the right side, suggesting metastatic pancreatic neuroendocrine tumor (PNET). Peptide receptor radionuclide therapy (PRRT) with [177Lutetium-DOTA0,Tyr3] octreotate was performed on the patient, with no side effects observed. She was discharged from the hospital 10 days after the first cycle.

Negative illness perceptions are associated with impaired quality of life in patients after long-term remission of Cushing's syndrome.

OBJECTIVE: Illness perceptions pertain to the pattern of beliefs patients develop about their illness. Illness perceptions are determinants of quality of life (QoL). Factors contributing to persisting impaired QoL after Cushing's syndrome (CS) remain largely unknown. Therefore, the objective of this study was to explore illness perceptions, as potentially modifiable psychological factors, in relation to QoL in patients with long-term remission of CS. DESIGN: Cross-sectional study. METHODS: We included patients with long-term remission of CS (n=52). Illness perceptions were evaluated using the Illness Perception Questionnaire (IPQ)-Revised, and QoL was measured using the physical symptom checklist, EuroQoL-5D (EQ-5D), and the CushingQoL. Reference data were derived from recent studies and included patients with vestibular schwannoma (n=80), acute (n=35) or chronic (n=63) pain, and chronic obstructive pulmonary disease (COPD; n=171). RESULTS: Illness perceptions showed a strong correlation with QoL. Patients with CS scored distinctively more negative on the IPQ compared with patients with vestibular schwannoma and patients with acute pain, and also reported more illness-related complaints (all P<0.01). There were also some differences in illness perceptions between patients with CS and patients with chronic pain and patients with COPD, but there was no distinct pattern. CONCLUSIONS: Patients after long-term remission of CS report more negative illness perceptions compared with patients with other acute or chronic conditions. Further research is needed to assess whether QoL in CS can be improved by addressing these illness perceptions, for example, by a self-management intervention program.

Cardiac dysfunction is reversed upon successful treatment of Cushing's syndrome.

OBJECTIVE: In patients with active Cushing's syndrome (CS), cardiac structural and functional changes have been described in a limited number of patients. It is unknown whether these changes reverse after successful treatment. We therefore evaluated the changes in cardiac structure and dysfunction after successful treatment of CS, using more sensitive echocardiographic parameters (based on two-dimensional strain imaging) to detect subtle changes in cardiac structure and function. METHODS: In a prospective study design, we studied 15 consecutive CS patients and 30 controls (matched for age, sex, body surface area, hypertension, and left ventricular (LV) systolic function). Multidirectional LV strain was evaluated by two-dimensional speckle tracking strain imaging. Systolic (radial thickening, and circumferential and longitudinal shortening) and diastolic (longitudinal strain rate at the isovolumetric relaxation time (SR(IVRT))) parameters were measured. RESULTS: At baseline, CS patients had similar LV diameters but had significantly more LV hypertrophy and impaired LV diastolic function, compared to controls. In addition, CS patients showed impaired LV shortening in the circumferential (-16.5+/-3.5 vs -19.7+/-3.4%, P=0.013) and longitudinal (-15.9+/-1.9 vs -20.1+/-2.3%, P<0.001) directions and decreased SR(IVRT) (0.3+/-0.15 vs 0.4+/-0.2/ s, P=0.012) compared to controls. After normalization of corticosteroid excess, LV structural abnormalities reversed, LV circumferential and longitudinal shortening occurred, and SR(IVRT) normalized. CONCLUSION: CS induces not only LV hypertrophy and diastolic dysfunction but also subclinical LV systolic dysfunction, which reverses upon normalization of corticosteroid excess.

[The medical management of Cushing's syndrome]. / Tratamiento farmacológico y seguimiento del síndrome de Cushing.

Cushing's syndrome results from prolonged exposure to excessive circulating glucocorticosteroids and is associated with significant morbidity and mortality. While the treatment of choice in most patients is surgical, the metabolic consequences of this syndrome, including hypertension and diabetes mellitus, increase the risks of such surgery. Hypercortisolemia and its sequelae can be efficiently reversed or controlled using medical therapy, either as a temporary measure prior to definitive treatment or as a longer-term treatment in some particularly difficult cases. Drug treatment has been targeted at the hypothalamic/pituitary level, the adrenal glands and at glucocorticoid receptors. The present review discusses the pharmacotherapeutic agents that have been used in Cushing's syndrome and the criteria for their use, as well as recent drugs that may improve the medical treatment of this complex endocrinological disorder in the future. Finally, the short-and long-term follow-up of patients with Cushing's syndrome after surgery is also discussed.

Radiation therapy in the treatment of pituitary tumors.

The treatment of pituitary tumors has progressed into a multidisciplinary approach that involves neurosurgeons, radiation oncologists, and endocrinologists. This has allowed improved outcomes in treatment of pituitary tumors due to a combination of surgical, medical, and radiation therapies. In this study, the authors review the role of radiation therapy in the treatment of pituitary adenomas.

Difficulties in diagnosis and management of ectopic Cushing syndrome.

A 18-year-old man presented to a local hospital with muscle weakness, facial edema, and a 6 kg weight gain over 2 months. After a complete work-up, he was diagnosed with pituitary Cushing syndrome and treated with a bilateral adrenalectomy for Cushing syndrome and pituitary radiotherapy for Nelson syndrome. Twenty-five years later, his ectopic source of adrenocorticotropic hormone was revealed as a pulmonary neuroendocrine tumor, and a pulmonary resection was performed. Subsequently, a biochemical and clinical remission including hyperpigmentation was achieved.

[Radiotherapy of pituitary tumours]. / A hypophysisdaganatok radioteráipiáija.

In this article, the role of conventional radiotherapy and radiosurgery in the management of pituitary tumors is discussed. After a brief review about the mechanism of action and different techniques of irradiation therapy, the therapeutic effectiveness and side effects are analysed in the various types of pituitary tumors. Conventional fractionated radiotherapy has long been used to control growth and/or hormonal secretion of residual or recurrent pituitary tumors. Nevertheless, there is still a controversy concerning patient selection for radiotherapy, because several potentially significant side effects including hypopituitarism may develop. Stereotactic radiosurgical methods may have several advantages over conventional radiotherapy; they can be applied, for example, in patients with residual or recurrent pituitary tumors who had previously received conventional radiotherapy. However, long-term follow-up data with these relatively new techniques are still limited.

Final adult height and body mass index after cure of paediatric Cushing's disease.

OBJECTIVE: Linear growth data after cure of paediatric Cushing's disease (CD) have been reported infrequently. We evaluated final adult height (FH) and body mass index (BMI) in a cohort of paediatric patients treated successfully for CD. PATIENTS AND METHODS: Fourteen patients (10 male, age range 6.4-16.6 years) fulfilled the diagnostic criteria for CD. All had had transsphenoidal surgery (TSS), combined with pituitary irradiation (RT) (45 Gy in 25 fractions) in six. All were cured (post-TSS cortisol < 50 nmol/l or mean cortisol post-RT < 150 nmol/l). Subjects analysed had bone ages at diagnosis of < 15 'years' (male) and < 13 'years' (female). RESULTS: At diagnosis, height SDS was [mean (range)]-2.5 (-4.2 to -0.8) and body mass index (BMI) SDS +2.7 (0.8-5.1). Following cure, 13 patients had GH deficiency (peak GH < 20 mU/l) and were treated with hGH (+ GnRH analogue in four). Height SDS at FH (n = 10) or latest assessment (n = 4) was -1.3 (-3.9-0.2) and increased compared to diagnosis (P < 0.01). The difference between final or latest height SDS and target height SDS was -1.2 (-3.3-0.5), that is less (P < 0.01) than the difference between the height SDS at diagnosis and target height SDS of -2.4 (-3.9 to -0.5). At final height or latest assessment, BMI SDS was +1.7 (0.4-6.2), being decreased compared to diagnosis (P < 0.05) but greater than the normal population (P < 0.01). CONCLUSION: Catch-up growth was demonstrated in paediatric patients cured from CD, with the majority achieving FH within target height range. Early diagnosis and treatment of GH deficiency is recommended to achieve optimal long-term growth. Excess adiposity remains a potential long-term complication.

Clinical and endocrine responses to pituitary radiotherapy in pediatric Cushing's disease: an effective second-line treatment.

Transsphenoidal surgery (TSS) is considered first-line treatment for Cushing's disease (CD). Options for treatment of postoperative persisting hypercortisolemia are pituitary radiotherapy (RT), repeat TSS, or bilateral adrenalectomy. From 1983 to 2001, we treated 18 pediatric patients (age, 6.4-17.8 yr) with CD. All underwent TSS, and 11 were cured (postoperative serum cortisol, <50 nM). Seven (39%) had 0900-h serum cortisol of 269-900 nM during the immediate postoperative period (2-20 d), indicating lack of cure. These patients (6 males and 1 female; mean age, 12.8 yr; range, 6.4-17.8 yr; 4 prepubertal; 3 pubertal) received external beam RT to the pituitary gland, using a 6-MV linear accelerator, with a dose of 45 Gy in 25 fractions over 35 d. Until the RT became effective, hypercortisolemia was controlled with ketoconazole (dose, 200-600 mg/d) (n = 4) and metyrapone (750 mg-3 g/d) +/- aminoglutethimide (1 g/d) or o'p'DDD (mitotane, 3 mg/d) (n = 3). All patients were cured after pituitary RT. The mean interval from RT to cure (mean serum cortisol on 5-point day curve, <150 nM) was 0.94 yr (0.25-2.86 yr). Recovery of pituitary-adrenal function (mean cortisol, 150-300 nM) occurred at mean 1.16 yr (0.40-2.86 yr) post RT. At 2 yr post RT, puberty occurred early in one male patient (age, 9.8 yr) but was normal in the others. GH secretion was assessed at 0.6-2.5 yr post RT in all patients: six had GH deficiency (peak on glucagon/insulin provocation, <1.0-17.9 mU/liter) and received human GH replacement. Follow-up of pituitary function 7.6 and 9.5 yr post RT in two patients showed normal gonadotropin secretion and recovery of GH peak to 29.7 and 19.2 mU/liter. The seven patients were followed for mean 6.9 yr (1.4-12.0 yr), with no evidence of recurrence of CD. In conclusion, pituitary RT is an effective and relatively rapid-onset treatment for pediatric CD after failure of TSS. GH deficiency occurred in 86% patients. Long-term follow-up suggests some recovery of GH secretion and preservation of other anterior pituitary function.

Radiation therapy for Cushing's disease: a review.

Because patients with Cushing's disease have an increased morbidity and an age-corrected mortality, treatment is generally started as soon as possible. The goal of treatment in these patients is to induce remission. Although a variety of treatments are available, pituitary radiation is a good option for aggressive Cushing's disease that fails to respond to surgery, disease that invades the cavernous sinus, and disease that relapses following an initial remission. Conventional radiation therapy, stereotactic radiosurgery, fractionated stereotactic radiation therapy, and brachytherapy with Yttrium-90 (Y 90) and Gold-198 (Au 198) have been used successfully to treat ACTH-secreting pituitary adenomas in specialized centers. Conventional radiation therapy is the most frequently used method of radiation therapy for Cushing's disease. Stereotactic radiosurgery may be used as an alternative in patients with adenomas that are smaller than 30 mm and located at least 3 to 5 mm from the optic chiasm. Fractionated stereotactic radiation therapy is an alternative to radiosurgery while interstitial pituitary irradiation is an alternative to surgical resection in invasive tumors. Hypopituitarism is the most common side effect of pituitary irradiation. This article will review the role of radiation in the primary and secondary treatment in patients with Cushing's disease caused by pituitary adenomas.

Postoperative plasma cortisol levels predict long-term outcome in patients with Cushing's disease and determine which patients should be treated with pituitary irradiation after surgery.

Transsphenoidal surgery is the treatment of choice for ACTH-producing pituitary adenoma (Cushing's disease) and pituitary irradiation is widely considered the most appropriate treatment for patients with Cushing's disease for whom transsphenoidal surgery has been unsuccessful. We studied 49 consecutive patients who underwent transsphenoidal surgery for the treatment of Cushing's disease at Tokyo Women's Medical University from 1977-1997 with a mean follow-up duration of 87.6 months (range, 24-253 months). We examined the relationship between postoperative endocrinological data, assessed between 3 and 8 weeks after surgery, and long-term outcome and efficacy of pituitary irradiation after surgery. Long-term remission was defined as the regression of the symptom and signs of Cushing's syndrome, and restoration of normal levels of plasma ACTH, cortisol and urinary free cortisol, together with adequate suppression of morning plasma cortisol levels following the administration of low dose (1 mg) of dexamethasone. Thirty patients had no additional treatment after pituitary surgery. Only 1 of 25 patients (4%) whose postoperative plasma cortisol level was less than 2 microg/dl developed recurrent disease whereas 3 out of 5 patients with postoperative plasma cortisol levels higher than 2 microg/dl relapsed. Postoperative external pituitary radiation was used to treat the remaining 19 patients. Four patients who received radiation therapy had a low or undetectable postoperative plasma cortisol level (<2 microg/dl, 56 nmol/L) and all of these patients developed hypopituitarism whereas 5 patients with subnormal plasma cortisol levels (2.0-10.0 microg/dl) remained in remission. Among 10 patients with persistent disease after surgery, 6 entered remission 6-47 months after irradiation but one of them subsequently relapsed after 108 months. These results suggest that 1) additional therapy should be avoided in patients with a postoperative plasma cortisol less than 2 microg/dl because relapse is very rare and radiotherapy will frequently induce hypopituitarism, 2) patients with a subnormal cortisol level following surgery should be treated with pituitary irradiation, because the relapse rate is reportedly high and radiotherapy is effective in preventing relapse, 3) radiotherapy in patients with persistent disease after surgery is effective only in 50% (5/10) of the patients.

Linear growth and final height after treatment for Cushing's disease in childhood.

Cushing's disease is associated with growth failure in childhood and adolescence. Growth and final height were analyzed in 10 patients who were cured or in remission after treatment of Cushing's disease. Seven males and 3 females, aged 6.8-17.6 yr (bone age, 3.3-15.4 yr), had transsphenoidal surgery, which was combined with pituitary irradiation (4,500 cGy in 25 fractions) in 5 patients. At presentation, 5 patients were prepubertal (males), and 5 were pubertal (2 males and 3 females). The mean height SD score was -2.15 +/-1.26 (range, -0.21 to -4.32) compared with mean target height SD score of -0.43 +/- 0.58. Height velocity in 6 patients was subnormal (0.9-3.8 cm/yr). After treatment, short-term height velocity, over a mean interval of 0.57 yr, in 8 patients not receiving human GH (hGH) therapy, was variable (range, 0.8-7.6 cm/yr). GH stimulation tests (insulin tolerance test/glucagon) in 9 subjects showed peak GH levels of 0.5-20.9 mU/L. Eight were treated with hGH (14 IU/m2 wk), combined in 2 girls and 1 boy with a GnRH analog. After 1 yr of hGH, the mean height SD score had increased from -2.45 +/- 1.0 at initiation of hGH to -2.07 +/- 1.2 (P = 0.01). GH therapy was continued until final height or latest assessment. The mean final height SD score (n = 6) was - 1.24 +/- 1.38, and at the latest assessment the mean height SD score (n = 4) was - 1.52 +/- 1.33. Combining these 2 groups, the mean height so score was -1.36 +/- 1.29. The difference between final or latest height SD score and target height SD score was 0.93 +/- 1.13, i.e. less (P = 0.005) than the difference between height and target height SD score of 1.72 +/- 1.26 at presentation. In conclusion, catch-up and favorable long-term growth was seen after treatment for Cushing's disease. Posttreatment GH deficiency was frequent, and early hGH replacement may have contributed to the encouraging outcome.

Usefulness of the desmopressin test in the postoperative evaluation of patients with Cushing's disease.

OBJECTIVE: To evaluate the plasma ACTH and serum cortisol responses to desmopressin in patients with Cushing's disease either before or after pituitary adenomectomy during long-term follow-up, and to compare the results with those obtained after corticotrophin-releasing hormone (CRH) testing. DESIGN: Plasma ACTH and serum cortisol concentrations were evaluated after the administration of desmopressin (10 microg i.v.) or CRH (1 microg/kg i. v.) in 34 patients with Cushing's disease. Twenty-four patients with active Cushing's disease were evaluated both before and after transsphenoidal pituitary surgery (TSS); these patients were followed up for 1-36 months. Ten patients were studied only after a long-term period (1-19 years, median 4 years) after TSS (six patients), TSS plus external pituitary irradiation (three patients) and TSS plus radiosurgery (one patient). RESULTS: In 24 patients with active Cushing's disease a significant ACTH/cortisol response (P<0.001) was induced by either desmopressin (ACTH from a baseline of 15.3+/-2.7 pmol/l to a peak of 40.9+/-7.3 pmol/l; cortisol from 673+/-59 nmol/l to 1171+/-90 nmol/l) or CRH (ACTH from a basal of 14. 2+/-2.5 pmol/l to a peak of 47.2+/-7.7 pmol/l; cortisol from 672+/-50 nmol/l to 1192+/- 80 nmol/l). In all patients a positive cortisol response to desmopressin was found. After pituitary adenomectomy the 14 'cured' patients were followed up for 1-36 months; desmopressin administration never induced ACTH or cortisol responsiveness in any patient. In contrast, a progressive recovery of ACTH and cortisol responses after CRH was observed at different intervals of time in all patients but one. Five patients, in whom the cortisol concentration only normalized after surgery, showed a persistent responsiveness to desmopressin, and two of them relapsed 12 and 24 months later. In five patients who were not cured, the hormonal responsiveness to either CRH or desmopressin was similar before and after operation. Of 10 patients studied only after long-term follow-up, six were cured and a normal response to CRH was present, whereas no changes in ACTH/cortisol concentrations were induced by desmopressin. The other four unsuccessfully operated patients underwent pituitary irradiation and showed different and equivocal hormonal responses to desmopressin and to CRH. CONCLUSIONS: During the postoperative follow-up of patients with Cushing's disease, the maintenance or the disappearance of the hormonal response may be related to the persistence or the complete removal of adenomatous corticotrophs, respectively. It is suggested that desmopressin test should be performed in the preoperative evaluation and follow-up of patients with ACTH-dependent Cushing's syndrome.

Treatment of pituitary-dependent Cushing's syndrome: long-term results of unilateral adrenalectomy followed by external pituitary irradiation compared to transsphenoidal pituitary surgery.

BACKGROUND: The preferred treatment of Cushing's disease (CD) nowadays is transsphenoidal pituitary surgery (TPS). Prior to TPS, patients at the Leiden University Medical Centre were treated by unilateral adrenalectomy followed by external pituitary irradiation (UAPI). We report on long-term results of both UAPI and TPS and compare remission, relapse rates, and complications. PATIENTS AND METHODS: A retrospective study was carried out on 130 patients with CD. Patients with pituitary macroadenoma were excluded. Eighty-six and 44 patients underwent UAPI and TPS, respectively. Of these patients, 85 and 41 were evaluable for long-term results. RESULTS: Remission following UAPI and TPS was identical at 64% (54/85 and 27/41). Cumulative relapse was also comparable - 17% (9/54) and 22% (6/27), respectively, - for UAPI and TPS, although the mean follow-up periods were different - 21.4 years and 8.5 years, respectively. Cumulative disease-free survival curves after UAPI and TPS are identical until 5 years of follow-up, but diverge thereafter indicating more sustained remissions following UAPI (P = 0.17, Wilcoxon statistic). Pituitary dysfunction following UAPI (36%) and pituitary surgery (55%) likewise did not differ significantly. However, pituitary dysfunction was an immediate event after TPS, whereas it developed after a mean interval of 17.8 years following UAPI.Low-dose dexamethasone testing during follow-up had no value in predicting therapeutic outcome. CONCLUSIONS: The results of unilateral adrenalectomy followed by external pituitary irradiation do not justify that this therapy is totally abandoned in favour of transsphenoidal pituitary surgery. Unilateral adrenalectomy followed by external pituitary irradiation is a valid therapeutic modality for the treatment of Cushing's disease, and could be considered as alternative to bilateral adrenalectomy and under some circumstances to transsphenoidal pituitary surgery.

Growth hormone status following treatment for Cushing's syndrome.

OBJECTIVE: Both pituitary surgery and radiotherapy for Cushing's disease can lead to growth hormone (GH) deficiency. Studies to date have, however, described the incidence of impaired GH secretion and not the incidence of severe GH deficiency following treatment of Cushing's disease. Furthermore, following cure of Cushing's disease and resolution of hypercortisolaemia, recovery of GH secretory status is seen, thus creating uncertainty as to the persistence of any documented GH deficiency. This study has two aims; to determine the incidence of severe persistent GH deficiency following treatment of Cushing's disease and to assess the time scale of any recovery of GH secretory status following surgical cure of Cushing's disease. DESIGN AND PATIENTS: The case notes of 37 patients either cured or in clinical and biochemical remission following treatment for Cushing's syndrome were reviewed to determine the incidence of severe GH deficiency. Of 34 patients with Cushing's disease, 20 were treated by pituitary surgery, and 14 with radiotherapy. Three patients with adrenal adenomas underwent unilateral adrenalectomy. MEASUREMENTS: GH secretory status was assessed by provocative testing using an insulin tolerance test (ITT, 85% of all tests), glucagon stimulation test (GST) or arginine stimulation test (AST). RESULTS: Thirty-six percent (5/14) of radiotherapy treated patients demonstrated severe GH deficiency at a mean time of 99 months following remission. Fifty-nine percent (10/17) of surgically treated patients assessed in the two years following remission demonstrated severe GH deficiency, whilst only 22% (2/9) of patients assessed beyond two years following remission demonstrated severe GH deficiency. This latter cohort is biased, with patients in whom severe GH deficiency had been demonstrated on earlier tests being over-represented. It is more accurate to estimate the incidence of persistent severe GH deficiency following surgically induced remission of Cushing's disease by incorporating data from patients in whom original testing demonstrated adequate GH reserve. Collating such data, 13% (2/15) of patients had persistent severe GH deficiency. Across all time periods five surgically treated patients demonstrated recovery of GH secretory status over a median time course of 19 months. In the surgically treated cohort, seven (35%) patients had anterior pituitary hormone deficits other than GH deficiency: 14% (2/14) of patients with normal GH secretory status at the last assessment, 83% (5/6) of patients with severe GHD at the last assessment. Of the 5 patients who demonstrated recovery of GH secretory status 40% (2) had additional anterior pituitary hormone deficits. Within the radiotherapy treated cohort 14% (2/14) of patients demonstrated additional anterior pituitary hormone deficits: 11% (1/9) of patients with normal GH secretory status and 20% (1/5) of patients with severe GH deficiency. None of the patients with adrenal adenomas treated by unilateral adrenalectomy demonstrated any abnormality of GH secretory status CONCLUSIONS: The incidence of severe persistent GH deficiency following surgically induced or radiotherapy induced remission of Cushing's disease is lower than has been suggested by previous studies, although these latter studies have assessed GH insufficiency and not severe GH deficiency. In the presence of additional pituitary hormone deficits severe GHD is common and is likely to be persistent. Recovery of GH secretory status is seen in a high proportion of patients reassessed, at a median time of 19 months following surgically induced remission of Cushing's disease. Thus, we recommend that definitive assessment of GH secretory status is delayed for at least two years following surgical cure of Cushing's disease. This has important implications for patients in whom GH replacement therapy is being considered.