Venous thromboembolism in Cushing syndrome: results from an EuRRECa and Endo-ERN survey

Background

Patients with Cushing syndrome (CS) are at increased risk of venous thromboembolism (VTE).

Objective

The aim was to evaluate the current management of new cases of CS with a focus on VTE and thromboprophylaxis.

Design and methods

A survey was conducted within those that report in the electronic reporting tool (e-REC) of the European Registries for Rare Endocrine Conditions (EuRRECa) and the involved main thematic groups (MTG's) of the European Reference Networks for Rare Endocrine Disorders (Endo-ERN) on new patients with CS from January 2021 to July 2022.

Results

Of 222 patients (mean age 44 years, 165 females), 141 patients had Cushing disease (64%), 69 adrenal CS (31%), and 12 patients with ectopic CS (5.4%). The mean follow-up period post-CS diagnosis was 15 months (range 3-30). Cortisol-lowering medications were initiated in 38% of patients. One hundred fifty-four patients (69%) received thromboprophylaxis (including patients on chronic anticoagulant treatment), of which low-molecular-weight heparins were used in 96% of cases. VTE was reported in six patients (2.7%), of which one was fatal: two long before CS diagnosis, two between diagnosis and surgery, and two postoperatively. Three patients were using thromboprophylaxis at time of the VTE diagnosis. The incidence rate of VTE in patients after Cushing syndrome diagnosis in our study cohort was 14.6 (95% CI 5.5; 38.6) per 1000 person-years.

Conclusion

Thirty percent of patients with CS did not receive preoperative thromboprophylaxis during their active disease stage, and half of the VTE cases even occurred during this stage despite thromboprophylaxis. Prospective trials to establish the optimal thromboprophylaxis strategy in CS patients are highly needed.

Significance statement

The incidence rate of venous thromboembolism in our study cohort was 14.6 (95% CI 5.5; 38.6) per 1000 person-years. Notably, this survey showed that there is great heterogeneity regarding time of initiation and duration of thromboprophylaxis in expert centers throughout Europe.

Preoperative management of patients with ectopic Cushing's syndrome caused by ACTH-secreting pheochromocytoma: a case series and review of the literature

PURPOSE

ACTH-secreting pheochromocytoma is a rare cause of ectopic Cushing's syndrome, posing a clinical challenge for the severity of its clinical presentation, the difficulty in the prevention and the management of surgical complications. Sparse data are currently available about the optimal preoperative management of the severe symptoms due to both hypercortisolism and catecholamine excess, especially regarding the role and timing of medical therapies.

METHODS

We present a series of three patients with ACTH-secreting pheochromocytoma. A brief review of the available literature evidence on the preoperative management of this rare clinical condition is also conducted.

DISCUSSION

Patients with ACTH-secreting pheochromocytoma show peculiarities as compared to other forms of ACTH-dependent Cushing's syndrome, in terms of clinical presentation, preoperative management, and peri- and post-surgical short-term outcome. Pheochromocytoma should be ruled out in patient with ectopic CS of unknown origin because of the high anesthesiologic risk of proceeding to surgery with an undiagnosed pheochromocytoma. Proper preoperative recognition of complications of both hypercortisolism and catecholamines excess is the key to prevent the morbidity and mortality of an ACTH-producing pheochromocytoma. In these patients the absolute priority is to control excessive cortisol secretion since the rapid correction of the hypercortisolism is the most effective treatment of all the related comorbidities and it is mandatory to prevent severe complications during surgery, opting if necessary for a "block-and-replace" regimen.

CONCLUSION

Our additional cases and this literature review could provide a better understanding of the complications to be evaluated at diagnosis and some suggestions on their management during the preoperative period.

S-GRAS score for prognostic classification of adrenocortical carcinoma: an international, multicenter ENSAT study

OBJECTIVE

Adrenocortical carcinoma (ACC) has an aggressive but variable clinical course. Prognostic stratification based on the European Network for the Study of Adrenal Tumours stage and Ki67 index is limited. We aimed to demonstrate the prognostic role of a points-based score (S-GRAS) in a large cohort of patients with ACC.

DESIGN

This is a multicentre, retrospective study on ACC patients who underwent adrenalectomy.

METHODS

The S-GRAS score was calculated as a sum of the following points: tumour stage (1-2 = 0; 3 = 1; 4 = 2), grade (Ki67 index 0-9% = 0; 10-19% = 1; ≥20% = 2 points), resection status (R0 = 0; RX = 1; R1 = 2; R2 = 3), age (<50 years = 0; ≥50 years = 1), symptoms (no = 0; yes = 1), and categorised, generating four groups (0-1, 2-3, 4-5, and 6-9). Endpoints were progression-free survival (PFS) and disease-specific survival (DSS). The discriminative performance of S-GRAS and its components was tested by Harrell's Concordance index (C-index) and Royston-Sauerbrei's R2D statistic.

RESULTS

We included 942 ACC patients. The S-GRAS score showed superior prognostic performance for both PFS and DSS, with best discrimination obtained using the individual scores (0-9) (C-index = 0.73, R2D = 0.30, and C-index = 0.79, R2D = 0.45, respectively, all P < 0.01vs each component). The superiority of S-GRAS score remained when comparing patients treated or not with adjuvant mitotane (n = 481 vs 314). In particular, the risk of recurrence was significantly reduced as a result of adjuvant mitotane only in patients with S-GRAS 4-5.

CONCLUSION

The prognostic performance of S-GRAS is superior to tumour stage and Ki67 in operated ACC patients, independently from adjuvant mitotane. S-GRAS score provides a new important guide for personalised management of ACC (i.e. radiological surveillance and adjuvant treatment).

ENSAT registry-based randomized clinical trials for adrenocortical carcinoma

Adrenocortical carcinoma (ACC) is an orphan disease lacking effective systemic treatment options. The low incidence of the disease and high cost of clinical trials are major obstacles in the search for improved treatment strategies. As a novel approach, registry-based clinical trials have been introduced in clinical research, so allowing for significant cost reduction, but without compromising scientific benefit. Herein, we describe how the European Network for the Study of Adrenal Tumours (ENSAT) could transform its current registry into one fit for a clinical trial infrastructure. The rationale to perform randomized registry-based trials in ACC is outlined including an analysis of relevant limitations and challenges. We summarize a survey on this concept among ENSAT members who expressed a strong interest in the concept and rated its scientific potential as high. Legal aspects, including ethical approval of registry-based randomization were identified as potential obstacles. Finally, we describe three potential randomized registry-based clinical trials in an adjuvant setting and for advanced disease with a high potential to be executed within the framework of an advanced ENSAT registry. Thus we, therefore, provide the basis for future registry-based trials for ACC patients. This could ultimately provide proof-of-principle of how to perform more effective randomized trials for an orphan disease.

AME position statement on adrenal incidentaloma

OBJECTIVE

To assess currently available evidence on adrenal incidentaloma and provide recommendations for clinical practice.

DESIGN

A panel of experts (appointed by the Italian Association of Clinical Endocrinologists (AME)) appraised the methodological quality of the relevant studies, summarized their results, and discussed the evidence reports to find consensus.

RADIOLOGICAL ASSESSMENT

Unenhanced computed tomography (CT) is recommended as the initial test with the use of an attenuation value of ≤10 Hounsfield units (HU) to differentiate between adenomas and non-adenomas. For tumors with a higher baseline attenuation value, we suggest considering delayed contrast-enhanced CT studies. Positron emission tomography (PET) or PET/CT should be considered when CT is inconclusive, whereas fine needle aspiration biopsy may be used only in selected cases suspicious of metastases (after biochemical exclusion of pheochromocytoma). HORMONAL ASSESSMENT: Pheochromocytoma and excessive overt cortisol should be ruled out in all patients, whereas primary aldosteronism has to be considered in hypertensive and/or hypokalemic patients. The 1 mg overnight dexamethasone suppression test is the test recommended for screening of subclinical Cushing's syndrome (SCS) with a threshold at 138 nmol/l for considering this condition. A value of 50 nmol/l virtually excludes SCS with an area of uncertainty between 50 and 138 nmol/l.

MANAGEMENT

Surgery is recommended for masses with suspicious radiological aspects and masses causing overt catecholamine or steroid excess. Data are insufficient to make firm recommendations for or against surgery in patients with SCS. However, adrenalectomy may be considered when an adequate medical therapy does not reach the treatment goals of associated diseases potentially linked to hypercortisolism.

Somatostatin analogs and gallstones: a retrospective survey on a large series of acromegalic patients

CONTEXT

Development of gallstones (GS) is reported during the use of somatostatin analogs (SA) that are at present the mainstay for the medical treatment of acromegaly.

OBJECTIVE

To review the prevalence and clinical and biochemical correlates of GS in acromegalic patients.

DESIGN AND SETTING

Retrospective survey on hospital records in acromegalic patients followed up in the last 20 yr in tertiary referral centers.

PATIENTS

Four hundred and fifty-nine patients (272 females).

MAIN OUTCOME MEASURES

According to SA use and GS occurrence, patients were divided in 4 groups: 1) treated with SA without GS (SA+GS-), 2) GS developed while on SA (SA+GS+), 3) GS without SA use (SA-GS+), 4) neither GS nor SA (SA-GS-).

RESULTS

Patients were unevenly distributed in the 4 groups: 232, 125, 38, 64, respectively, pointing to a prevalence of GS in acromegaly of 8.3% at diagnosis with an additional 35% developing GS during SA. GS occurred after 3 months-18 yr (median 3 yr) of SA treatment, were diagnosed after symptoms in 17.6%, were associated to steatosis, ultrasound biliary dilation, and biochemical cholestasis, in 25.6%, 12.8%, and 4% of patients, respectively. Ursodehoxicolic acid was administered after GS occurrence, causing their dissolution in 39% of patients after 3-48 months (median 12). Cholecystectomy was performed in 16.8%of patients in group 2. At multivariate analysis obesity, dyslipidemia, and SA treatment were independent predictors of GS onset, whereas gender and age were not.

CONCLUSIONS

GS are a frequent occurrence in acromegalic patients treated with SA, may occur at any time, but are seldom symptomatic or prompt acute surgery. Obesity and dyslipidemia appear to play a major role in the occurrence of GS in acromegalic patients on SA treatment.

Evaluation of proopiomelanocortin mRNA in the peripheral blood from patients with Cushing's syndrome of different origin

ACTH-dependent Cushing's syndrome is due to ACTH overproduction originating from a pituitary corticotroph adenoma (Cushing's disease) or from ectopic tumors (ectopic ACTH syndrome). Due to difficulties in the differential diagnosis between these two forms of hypercortisolism it would be important to have molecular tools able to discriminate the two conditions. It is known that proopiomelanocortin (POMC) gene transcription can originate messengers of different length. ACTHomas show the normal 1072 nucleotides (nt) transcript, whereas ectopic tumors seem to be associated with a longer mRNA form (1450 nt). In order to analyse the presence of different POMC transcripts, we extracted total RNA from peripheral lymphocytes of 10 patients with Cushing's disease, 10 with ectopic Cushing syndrome, and 20 controls as well as from pituitary tissues (2 ACTH-omas and a normal pituitary polyA+ sample). Northern blot analysis correctly revealed a 1072 nt mRNA molecule in pituitary ACTH-oma and in the normal pituitary polyA+ RNA samples, whereas neither this molecule nor other alternative transcripts were detected in blood samples from patients and controls. These data were confirmed by the more sensitive RT-PCR technique. This study further underlines the need for alternative approaches in the diagnosis of ACTH-dependent Cushing's syndrome.

Efficacy of a slow-release formulation of lanreotide (Autogel) 120 mg) in patients with acromegaly previously treated with octreotide long acting release (LAR): an open, multicentre longitudinal study

OBJECTIVE

Lanreotide Autogel 120 mg (ATG120; Ipsen S.p.A, Milan, Italy) is a high-dose, sustained-release aqueous gel formulation, supplied in a prefilled syringe and given by deep subcutaneous injection. The aim of this study was to compare efficacy and tolerability of ATG120 given every 4-8 weeks with those of octreotide LAR (o-LAR) given every 4 weeks. DESIGN PATIENTS AND INTERVENTION: A phase III multicentre Italian open clinical study of 23 acromegalic patients (15 female, 8 male). All patients had received o-LAR for 6-18 months and, after 3 months wash out, ATG120 was given every 6 weeks for a total of four injections (Period 1). Then the interval between ATG120 injections was adjusted according to three different schemes: every 4, 6 or 8 weeks depending on GH levels (GH > 2.5 microg/l; 1 < GH <or= 2.5 microg/l; GH <or= 1 microg/l, respectively). ATG120 was given for a further two to three doses, with a final assessment (Period 2) at Week 34, 36 or 42.

MEASUREMENTS

Hormonal (GH and IGF-I) and clinical efficacy and tolerability.

RESULTS

ATG120 induced a significant GH decrease from 9.9 +/- 11.3 at baseline (Visit 1) to 3.5 +/- 5.7 at the end of Period 1 (P < 0.01) and to 3.8 +/- 5.7 microg/l at the final visit (P < 0.01). IGF-I also decreased from 544 +/- 312 at baseline (Visit 1) to 318 +/- 181 at Period 1 and to 356 +/- 187 microg/l at the final visit (both P < 0.05 vs. baseline). The frequency of ATG120 administrations was adjusted to every 4 weeks in 12 patients, every 6 weeks in 4 patients and every 8 weeks in 6 patients; 1 patient withdrew before the dose adjustment. Serum GH and IGF-I achieved at the end of Period 1 and Period 2 were similar to those reached with o-LAR. The number of patients who achieved GH < 2.5 microg/l was comparable between o-LAR (43%) and ATG120 at Period 1 (48%) and at Period 2 (62%). Normal IGF-I levels were recorded in 8 patients during o-LAR (35%), 11 during ATG Period 1 (48%) and 10 at the final visit (43%). Last, 4 patients showed a better response to ATG120 and 2 to o-LAR.

CONCLUSIONS

Lanreotide Autogel 120 mg is an effective and well-tolerated therapy for acromegaly. In approximately half of patients ATG120 may be administered every 6-8 weeks, instead of every 4 weeks, without lost of efficacy.

R990G polymorphism of the calcium-sensing receptor and renal calcium excretion in patients with primary hyperparathyroidism

CONTEXT

Primary hyperparathyroidism (PHPT) shows a great variability in clinical course and severity. Data concerning the association between polymorphic variants of the gene encoding the calcium-sensing receptor (CaSR) and clinical characteristics of PHPT are not conclusive.

OBJECTIVE

To evaluate the frequency of three polymorphisms; A986S, R990G, and Q1011E of CaSR in patients with PHPT and to correlate the genotypes with clinical and biochemical parameters.

PATIENTS AND METHODS

The study included 94 consecutive unrelated patients referred to our Departments for PHPT diagnosis and management between 2000 and 2005 and 137 age and sex-matched healthy subjects. Patients and controls were genotyped according to standard procedures. Due to the rarity of 990G allele, homozygous and heterozygous subjects were grouped in R/G+G/G set. All PHPT patients were studied for calcium metabolism parameters and renal and bone complications.

RESULTS

The proportion of CaSRvariants was similar in PHPT patients and controls. In PHPT patients, only R990G polymorphism was associated with disease parameters; in comparison with R/R, R/G+G/G patients showed lower mean serum parathyroid hormone (PTH) and phosphate levels (139.9 +/- 62.2 vs 199.9 +/- 136.3 pg/ml, P < 0.05 and 0.69 +/- 0.12 vs 0.81 +/- 0.18 mmol/l, P = 0.031 respectively), higher mean 24-h urine calcium concentration and calcium excretion (9.05 +/- 2.05 vs 6.77 +/- 4.31 mmol/24 h, P = 0.012 and 67 +/- 20 vs 51 +/- 26 mumol/l GF, P = 0.039), and increased prevalence of nephrolithiasis (90.0 vs 44.2%, P = 0.007).

CONCLUSIONS

The study showed that patients with PHPT, bearing the 990G allele, had lower serum PTH levels and higher urinary calcium excretion in comparison with the other genotype, suggesting an increased sensitivityof the variant receptor to extracellular calcium. Since this variant was associated with increased occurrence of nephrolithiasis, analysis of this polymorphism might help to predict renal complication of the disease.

Benzo[a]pyrene-enhanced mutagenesis by man-made mineral fibres in the lung of lamda-lacI transgenic rats

In an attempt to examine the interaction of man-made mineral fibres with benzo[a]pyrene (B[a]P), homozygous X-lacI transgenic F344 rats were intratracheally treated with rock (stone) wool RWI and glass wool MMVF 10 fibres together with B[a]P. To analyze the induction of gene mutations by fibres and B[a]P in lung, single doses of 1 and 2 mg fibres/animal or multiple doses of 2 mg fibres/animal were administered weekly on 4 consecutive weeks (total dose 8 mg/animal). B[a]P (10 mg/animal) was administered either simultaneously with fibres (for single dose treatment with fibres) or together with the last fiber treatment (for multiple dose treatment with fibres). Animals were scarified 4 weeks after the last treatment. Benzo[a]pyrene administered simultaneously with RW1 fibres exhibited a strong synergistic effect on mutagenicity, the observed mutant frequency (MF) being more than three-fold higher than the net sum of the MF induced after separate administration of both agents. Our data suggest that DNA adducts induced by simultaneous B[a]P and fiber treatment lead to a strong increase in mutatant frequencies.

Mutagenesis by man-made mineral fibres in the lung of rats

The potential of two asbestos substitute mineral fibres--rock (stone) wool RW1 and glass wool MMVF10--to induce gene mutations, DNA strand breaks, inflammation and oxidative stress has been studied in rats. Male homozygous lamda-lacI transgenic F344 rats were intratracheally instilled with single doses of 1 and 2 mg/animal of fibres or with multiple doses of 2 mg/animal administered weekly on four consecutive weeks (8 mg in total). Exposure to RW1 fibres for 16 weeks significantly increased mutant frequency (MF) in the lung in a dose-dependent manner, while MMVF10 fibres did not exhibit any increase of MF at any dose. RW1 fibres gave a significant increase of MF at a dose of 1 mg. Four weeks after instillation, neither the single nor the multiple doses significantly increased MF for both fibre types. To investigate mechanisms for induction of mutations, other genotoxicity markers and parameters of inflammatory and oxidative damage were determined in relation to MF. A weak correlation of mutagenicity data with other genotoxicity parameters studied was observed. DNA strand breaks as measured by comet assay were increased in alveolar macrophages and lung epithelial cells of RW1 and MMVF10 treated rats. RWl fibres caused more extensive lung inflammation as measured by release of neutrophils into broncho-alveolar lavage fluid than MMVF10 fibres. The effects were observed 16 weeks post-exposure, indicating a persistence of the pathogenic process during the exposure period. Only minor differences in the extent of inflammatory processes were observed between the doses of 2 mg and 4 x 2 mg, suggesting that any threshold for inflammation lies below the dose of 2 mg. With the exception of the highest dose of MMVF10 fibres after 16 weeks of exposure, no significant increase of oxidative damage as measured by levels of malondialdehyde in lung tissue was observed. MMVF10 fibres caused weaker inflammation in the lung of rats and did not exhibit any mutagenic effect. We conclude that a weak but chronic inflammation (more likely than acute inflammation or direct oxidative damage) in the lung tissue of fibre treated rats characterized by moderate influx of inflammatory cells into BAL is probably responsible for the observed mutagenic effect of RW1 fibres.

Use of radioguided surgery with [111In]-pentetreotide in the management of an ACTH-secreting bronchial carcinoid causing ectopic Cushing's syndrome

Intraoperative [111In]-pentetreotide scintigraphy with a hand-held gamma detector probe has recently been proposed to increase the intraoperative detection rate of small neuroendocrine tumors and their metastases. We report a case of a 28-yr-old woman with ectopic Cushing's syndrome due to an ACTH-secreting bronchial carcinoid, in whom the use of radioguided surgery improved disease management. At presentation, radiolabeled pentetreotide scintigraphy was the only procedure able to detect the ectopic source of ACTH. After radiologic confirmation, the patient underwent removal of a bronchial carcinoid, with disease persistence. After surgery, pentetreotide scintigraphy showed pathologic uptake in the mediastinum not previously detected at surgery and only subsequently confirmed by radiologic studies. Despite a second thoracic exploration, hormonal, scintigraphic, and radiological evidence of residual disease persisted. Radioguided surgery was then performed using a hand-held gamma probe 48 h after iv administration of a tracer dose of radiolabeled [111In-DTPA-D-Phe1]-pentetreotide, which permitted detection and removal of multiple residual mediastinal lymph node metastases. Clinical and radiologic cure, with no evidence of tracer uptake at pentetreotide scintigraphy, was subsequently observed. The use of an intraoperative gamma counter appears a promising procedure in the management of metastatic ACTH-secreting bronchial carcinoids.

Treatment of acromegaly with SS analogues: should GH and IGF-I target levels be lowered to assert a tight control of the disease?

BACKGROUND

in acromegaly, the criteria for the cure of the disease after neurosurgery have become tighter and tighter. In contrast, the evaluation of control of disease activity during medical treatment is based upon the normalisation of IGF-I levels and epidemiological criteria, i.e. lessening GH (assessed by RIA) to levels reported to normalise increased mortality. The aim of this study was to evaluate GH and IGF-I suppression during prolonged SS analogues (SA) treatment. The concordance between "safe" GH and normalised IGF-I levels during SA was also assessed, according to gender and gonadal status.

DESIGN

multicentre, retrospective. Patients. GH/IGF-I levels were evaluated in 207 acromegalic patients (132 females, aged 20-85 yr) during a prolonged treatment (longer than 12 months) with individually tailored doses of depot SA( lanreotide or octreotide-LAR in 97 and 110 patients, respectively). Final IGF-I levels were transformed in z-scores using data collected in a large cohort of normal subjects of 3 different age groups (20-40 yr old, 41-60 yr old, 61-80 yr old, n=160, 148, 115, respectively), that allowed to set up quartiles of normality (I = 3rd-25th percentile, II = 26th-50th, III = 51th-75th, IV = 76th-97th).

RESULTS

fifty-nine and 19.3% of patients achieved GH levels <2.5 and <1 microg/l, respectively. IGF-I were normalised (z-score between 2 and -2) in 58.4% of patients. The distribution of normal IGF-I values among quartiles was uneven: 7%, 19%, 25%, and 49% of values were distributed in the I, II, III, and IV quartile, respectively. The concordance between GH and IGF-I values was poor: 28.4% of patients attaining GH values <2.5 microg/l had still pathological IGF-I (even 12.5% of those with GH <1 microg/l), and 39.3% of those with GH levels still above the "safe" limit had "nor IGF-I. Although proportions of IGF-I normalisation were not different between males and females, the regression line obtained between GH and IGF-I z-score showed the same slope but with a significantly lower intercept in regularly cycling women than in males and in postmenopausal females. Thus for any GH value, cycling females had lower IGF-I than menopausal women and males, and their IGF-I normalisation could be achieved by higher GH values. By ROC analysis, the achievement of normal IGF-I was predicted by the GH value of 1.8 microg/l in males and 2.4 microg/l in females.

CONCLUSIONS

in acromegalic patients on SA treatment, GH and IGF-I levels are often not concordant. In addition to age, sex is to be taken into account in the evaluation of hormonal targets. A better refinement of GH and IGF-I targets to be reached while on treatment with SA is warranted.

Mutagenesis by asbestos in the lung of lambda-lacI transgenic rats

In order to get more insight into the mechanism of asbestos-related lung cancer, the mutagenic potential of asbestos was examined in vivo in rat lung. Groups of five transgenic lambda-lacI (Big Blue) rats were intratracheally instilled with single doses of 1 or 2mg, or with four weekly doses of 2mg, per animal of the amosite asbestos. Sixteen weeks after instillation, the mutation frequency was found to be increased in lung DNA by 2-fold at doses of 2 mg (P = 0.035) and of 4 x 2 mg (P = 0.007) amosite. No significant changes were observed after 4 weeks of exposure. In separate experiments, wild-type F344 rats were treated by the same regimen as described above and markers of inflammation, genotoxicity, cell proliferation and lung tissue damage were analysed. Our results indicate a weak but persistent inflammation and cell proliferation which possibly plays a major role in the observed mutagenic effect.

Benzo[a]pyrene-enhanced mutagenesis by asbestos in the lung of lambda-lacI transgenic rats

To study the suspected mechanism of the interaction between tobacco smoking and asbestos exposure in the modulation of cancer risk, the mutagenic potential of asbestos in combination with the tobacco smoke carcinogen benzo[a]pyrene (B[a]P) was examined in vivo in the rat lung. B[a]P was administered intratracheally in one set of experiments, or by two daily intraperitoneal injections in another set of experiments, to lambdalacI transgenic rats, together with 1, 2 or 4 x 2 mg amosite in one experiment. In the first experiment, the combined action of amosite and B[a]P caused a synergistic (superadditive) increase of mutation frequency in the lung, as compared to groups treated only with asbestos or B[a]P. In the second experiment, i.p. treatment with B[a]P did not significantly alter the mutation frequency induced by amosite, neither after 4 nor after 16 weeks of exposure. The B[a]P-DNA adduct levels were unaffected by amosite co-treatment in both experiments. We assume that the synergistic increase of mutation frequency after intratracheal treatment was due to the mitogenic activities of B[a]P and of amosite. In conclusion, our findings indicate that a weak and delayed mutagenic effect of amosite in rat lung observed in another study was strongly enhanced by the concomitant action of B[a]P. The striking enhancement effect of B[a]P may provide a basis for understanding the suspected synergism of smoking on asbestos carcinogenesis.

Assessing the presence of abnormal regulation of cortisol secretion by membrane hormone receptors: in vivo and in vitro studies in patients with functioning and non-functioning adrenal adenoma

Regulation of cortisol secretion by aberrant hormone receptors may play a role in the pathogenesis of ACTH-independent Cushing's syndrome. In this study, the topic was evaluated by combining in vivo and in vitro approaches. Cortisol responses to various stimuli (standard meal, GnRH + TRH, cisapride, vasopressin, glucagon) were assessed in 6 patients with clinical or subclinical adrenal Cushing's syndrome, and non-functioning adrenal adenoma in two cases. Abnormal responses were observed in three patients with Cushing's syndrome; one patient showed a gastric inhibitory polypeptide (GIP)-dependent cortisol rise after meal, together with responses after GnRH and cisapride; the second patient showed an LH-dependent cortisol response to GnRH, and in the third cortisol rose after cisapride. The pattern of receptor expression performed by RT-PCR showed that while GIP-R was only expressed in tumor from the responsive patient, 5-hydroxytryptamine type 4 receptor and LH-R were also present in normal adrenal tissues and tissues from non-responsive patients. Interestingly, an activating mutation of Gsalpha gene was identified in one of these tumors. Therefore, cortisol responses to agents operating via Gs protein coupled receptors (in one case associated with Gsalpha mutation) were found in Cushing's patients, while these responses were absent in the others. The finding of receptor expression in normal and non-responsive tumors suggests that different mechanisms are probably involved in inducing in vivo cortisol responses.

Management of occult adrenocorticotropin-secreting bronchial carcinoids: limits of endocrine testing and imaging techniques

The differential diagnosis and the identification of the source of ACTH in occult ectopic Cushing's syndrome due to a bronchial carcinoid still represents a challenge for the endocrinologist. We report our experience in six patients with occult bronchial carcinoid in whom extensive hormonal, imaging, and scintigraphic evaluation was performed. All patients presented with hypercortisolism associated with high plasma ACTH values. The CRH test and high dose dexamethasone suppression test suggested an ectopic source of ACTH in three of six patients. During bilateral inferior petrosal sinus sampling, none of the patients showed a central to peripheral ACTH gradient. At the time of diagnosis, none of the patients had radiological evidence of the ectopic source of ACTH, whereas pentetreotide scintigraphy identified the lesion in two of four patients. Finally, a chest computed tomography scan revealed the presence of a bronchial lesion in all patients, and pentetreotide scintigraphy identified four of six lesions. In all patients a bronchial carcinoid was found and removed. In one patient with scintigraphic evidence of residual disease after two operations, radioguided surgery, using a hand-held gamma probe after iv administration of radiolabeled pentetreotide, was performed; this allowed detection and removal of residual multiple mediastinal lymph node metastases. In conclusion, our data show that there is not a single endocrine test or imaging procedure accurate enough to diagnose and localize occult ectopic ACTH-secreting bronchial carcinoids. Radioguided surgery appears to be promising in the presence of multiple tumor foci and previous incomplete removal of the tumor.

Growth hormone and prolactin responses to corticotrophin-releasing-hormone in patients with Cushing's disease: a paracrine action of the adenomatous corticotrophic cells?

OBJECTIVE

In patients with Cushing's disease multihormonal responses to ovine corticotrophin releasing hormone (oCRH) have been detected in blood from inferior petrosal sinuses. This finding has been explained by co-secretion of other hormones, in addition to ACTH, by the pituitary adenoma itself or by paracrine effects exerted by the adenoma on normal periadenomatous pituitary cells. To assess these hypotheses we compared the presence of a CRH induced GH and/or PRL response during inferior petrosal sinus sampling to the immunohistochemical detection of PRL and GH in adenomatous tissue removed from patients with Cushing's disease.

PATIENTS AND MEASUREMENTS

Twenty-two patients with Cushing's disease and two patients with ectopic ACTH syndrome due to a bronchial carcinoid were studied; each patient had undergone preoperative inferior petrosal sinus sampling for diagnostic purposes with determination of GH and PRL in addition to ACTH, before and after administration of oCRH. Immunohistochemical studies for ACTH, GH and PRL detection were carried out on adenomatous tissue removed at surgery in the patients with pituitary dependent Cushing's disease and on the carcinoid tumours from the two patients with ectopic ACTH syndrome.

RESULTS

All pituitary adenomas immunostained for ACTH, and four adenomas immunostained for GH or PRL in addition to ACTH. A PRL increase in the inferior petrosal sinus after oCRH administration was found in 11 of 22 patients, but none of their tumours immunostained for PRL. Immunostaining for PRL was found in the pituitary tumours from two patients but in neither patient was there a PRL response after oCRH. A GH response was found in 13 of 20 patients in whom it was sought; no patient showed immunostaining in their tumour. GH immunostaining was found in two tumours but in neither patient was there a GH response after oCRH. The oCRH-induced increase of GH and PRL was always recorded in the dominant inferior petrosal sinus. The ACTH response to oCRH was significantly higher in patients who showed oCRH induced increases in GH and/or PRL than in patients who did not, both in terms of area under the response-curve (22,032 +/- 9876 vs. 4371 +/- 2870 ng/l/10 min; P < 0.05) or mean percentage increase above baseline (754 +/- 229% vs. 147.2 +/- 67%, P < 0.02). A significant correlation was observed between ACTH and GH responses to oCRH. The two patients with ectopic Cushing's syndrome did not show ACTH, GH or PRL increases after oCRH administration and did not show immunostaining for GH or PRL in their tumours.

CONCLUSIONS

The present data do not support the hypothesis of co-secretion of hormones by the pituitary adenoma as the cause of the GH and PRL responses to ovine corticotrophin releasing hormone observed in patients with Cushing's disease; it is suggested that a different mechanism, possibly involving an interaction between the ACTH secreting adenoma and the normal periadenomatous GH and PRL secreting cells, may be responsible.

Additive effect of ketoconazole and octreotide in the treatment of severe adrenocorticotropin-dependent hypercortisolism

Over the last few years ketoconazole and octreotide have been employed in the treatment of pituitary-dependent or ectopic Cushing's syndrome. In four patients (two men and two women, aged 25-64 yr) with severe ACTH-dependent hypercortisolism in whom medical treatment with ketoconazole showed limited effectiveness and/or tolerability, we tried the association with octreotide. In all patients ketoconazole (200-1000 mg) induced a marked decrease in urinary free cortisol (UFC) excretion, but normalization could not be achieved. After ketoconazole discontinuation, three patients received octreotide alone (300-1500 micrograms/day, sc). This drug caused a dramatic decrease in UFC excretion, although not normalization; in all patients, escape from treatment occurred. Combined treatment was carried out for 10-180 days. Urinary cortisol excretion normalized and remained steadily within normal limits in three of four patients in whom normal UFC excretion had never been attained with both single drug regimens; in the fourth patient, UFC excretion decreased to levels lower than those achieved with ketoconazole or octreotide alone. The association with octreotide allowed a reduction in the daily dose of ketoconazole in three patients. Consistent with the steady reduction of cortisol production, a striking clinical improvement occurred in all patients after starting combined treatment. The normalization of UFC in three of four patients treated with both agents suggests that this approach may be useful in the long term treatment of severe forms of hypercortisolism of both pituitary and ectopic origin. In contrast to the limited effectiveness of each drug taken singularly at the same or higher doses, the association of the two drugs had an additive effect in the attainment of normal urinary cortisol excretion.

MR of corticotropin-secreting pituitary microadenomas

PURPOSE

To assess the accuracy of MR in the preoperative identification of corticotropin-secreting pituitary microadenomas.

METHODS

Twenty-six patients with clinical and biochemical evidence of pituitary-driven Cushing disease in whom MR of the seller region was performed were selected for this study. The MR examinations were retrospectively evaluated by a neuroradiologist who was aware of the presence of an adenoma at surgery but not of location and size of the lesion.

RESULTS

Considering the whole group of MR examinations performed either without (n = 26) or without and with intravenous injection of gadopentetate dimeglumine (n = 16), overall 20 MR studies were judged to show disease. Seventeen of 26 microadenomas were adequately shown and located by MR (true-positive, 65.4%). In three cases the sides of the microadenomas were misjudged (false-positive, 11.5%). Six patients had negative MR studies (false-negative, 23%). Twelve of the 16 patients studied after gadopentetate dimeglumine injection had true-positive MR findings (75%).

CONCLUSIONS

In our experience the accuracy of MR in detecting corticotropin-secreting microadenomas as small as 2 to 3 mm is 65% to 75%. Although precontrast images provide diagnostic information, the microadenoma can be better seen with administration of contrast material.

Stimulatory effect of oCRH on alpha-subunit secretion during petrosal sinus sampling in patients with Cushing's disease

During bilateral and simultaneous venous sampling of the inferior petrosal sinuses for preoperative localization of ACTH secreting microadenomas, alpha-subunit levels, in addition to ACTH, were determined in 9 patients with Cushing's disease. The aim of the study was to evaluate the possible occurrence of unilateral increases of alpha-subunit in basal conditions and the alpha-subunit responsiveness to oCRH. All the patients examined showed a central to peripheral and an intersinus gradient of ACTH concentrations before and/or after oCRH stimulation. Seven patients showed a central to peripheral alpha-subunit gradient in basal conditions. Lateralization of alpha-subunit concentrations was recorded in 4 patients in basal conditions (intersinus gradient > or = 1.55) and paralleled the side with the highest ACTH concentrations. After oCRH stimulation all but one patient showed a unilateral alpha-subunit increase in blood from the inferior petrosal sinus with the highest oCRH stimulated ACTH increase. The present data confirm the occurrence of an increase of alpha-subunit concentration in response to nonspecific stimulation with exogenously administered oCRH, concurrent with an ipsilateral increase of ACTH levels. The mechanism underlying this finding is still unclear, although a paracrine effect from the corticotroph tumour on adjacent pituitary tissue seems so far the most likely explanation.

Distal nephron function in Bartter's syndrome: abnormal conductance to chloride in the cortical collecting tubule?

Five patients with the clinical patterns of Bartter's syndrome underwent a series of clearance studies in order to characterize the underlying tubule defect. Free water generation during maximal water diuresis (CH2O), expressed as percentage of the distal delivery (CH2O + CCl), was lower in the patients (72.5 +/- 3.2%) than in controls (84.4 +/- 5.5, p < 0.0001). During maximal water diuresis and furosemide administration (40 mg i.v. as bolus), NaCl reabsorption along the diluting nephron segments could be separated into 2 components, that occurring in the loop of Henle (DRNaHL) and that occurring in tubule segments beyond the macula densa (DRNaDT): DRNaHL was normal, while DRNaDT was reduced (3.1 +/- 0.8 vs. 6.2 +/- 2.5 ml/min in controls, p < 0.015). Thus, according to this furosemide protocol, our patients had normal solute reabsorption in the loop of Henle but reduced NaCl reabsorption in tubule segments beyond the macula densa. During 0.9% saline infusion (2 liters in 2 h, after stimulation of distal Na reabsorption with fludrocortisone) fractional excretion (FE) of K showed a linear rise with the increase of FECl-FEK, however, was much higher in the patients than in controls for every FECl level. In contrast, the infusion of Na2SO4, after fludrocortisone administration, induced similar FEK increases in patients and in controls. Thus, in these patients Na reabsorption in the distal nephron (possibly the cortical collecting tubule) was associated with the generation of a higher than normal electric potential gradient in the presence of Cl but not of another poorly reabsorbable anion, such as SO4(2-). These observations indicate that, in our patients, Henle's loop function is normal, while the collecting tubule function is abnormal. We suggest that NaCl wasting and enhanced tubular secretion of H+ and K in our patients might result from an abnormally low conductance to Cl in distal nephron site(s) where Na reabsorption is electrogenic, possibly the cortical collecting tubule. A larger than normal transtubular electric gradient would be generated by Na reabsorption, causing: (1) a direct stimulation of tubular secretion of K and H+ (leading to hypokalemia and alkalosis) and (2) inhibition of the reabsorption of Na ('trapped' into the tubular lumen by electric forces), with consequent extracellular volume contraction, hyperreninemia and hyperaldosteronism.

Inferior petrosal sinus sampling: evidence of a stimulatory effect of oCRH on GH secretion in Cushing's disease

Preoperative localization of ACTH-secreting microadenomas has been performed in 9 patients with Cushing's disease by using bilateral and simultaneous venous sampling of the inferior petrosal sinuses. In addition to ACTH and PRL we determined GH levels after oCRH stimulation in order to confirm the possible occurrence of unilateral GH increases, as recently observed by us in one patient. A central-to-peripheral and an intersinus gradient of ACTH concentration was observed in all patients examined before and/or after oCRH stimulation. In 7 patients central-to-peripheral and side-to-side PRL gradients were recorded in basal conditions: in 5 of these patients a unilateral oCRH-induced PRL increase was observed. Six out of the 7 patients with unilateral PRL increases also showed an intersinus GH gradient in basal conditions (ratio greater than or equal to 1.5); in 5 of them a clearcut oCRH-induced GH increase was observed. A peripheral oCRH-induced GH and PRL increase was not observed in any of the patients. The observation of a paradoxical oCRH-induced GH increase in the inferior petrosal sinus with the higher ACTH concentration is of speculative and clinical interest; whether it reflects co-secretion of hormones by the tumour or hormone release by non-tumourous cells via paracrine mechanism is still to be clarified. The unilateral GH increase could represent an additional signal of the presence and localization of an ACTH-secreting tumour.

Bilateral and simultaneous venous sampling of inferior petrosal sinuses for ACTH and PRL determination: preoperative localization of ACTH-secreting microadenomas

We report our experience on venous sampling of the inferior petrosal sinuses for basal and CRH-stimulated ACTH and PRL gradients in 8 patients with surgically proven Cushing's disease who had normal preoperative neuroradiological studies. In 7 patients basal plasma ACTH concentrations in the inferior petrosal sinus ipsilateral to the tumor were higher than in the contralateral sinus; the gradients were enhanced by oCRH administration. In one out of two patients who had previously undergone unsuccessful pituitary microsurgery, neither basal nor oCRH-induced ACTH increases led to correct localization of the microadenoma within the pituitary. In 4 out of 7 patients basal serum PRL concentrations in the inferior petrosal sinus ipsilateral to the tumor were higher than in the contralateral; only two out of 4 showed an increase in PRL levels after oCRH injection. Our study confirms that simultaneous and bilateral venous sampling of inferior petrosal sinuses is a valuable means to identify the site of microadenomas in patients with Cushing's disease without neuroradiological evidence of the tumor. This procedure may give misleading results in patients previously operated on. Unilateral or predominant increases of PRL concentration during catheterization of the inferior petrosal sinuses, when present, always lateralize to the side of the corticotroph adenoma, providing a possible additional signal of the presence of the tumor.

Size reduction of an ACTH-secreting pituitary macroadenoma in Nelson's syndrome by sodium valproate: effect of withdrawal and re-institution of treatment

We describe herein the reduction in the size of an ACTH-secreting pituitary macroadenoma in a patient with Nelson's syndrome during chronic administration of sodium valproate, and the changes in tumour volume after withdrawal and re-institution of treatment. The patient had elevated plasma ACTH levels (1123-1255 pmol/l), which increased markedly after CRH stimulation. A first 4-month course of sodium valproate administration (600 mg/day, orally) was started. Plasma ACTH fell to 550-726 pmol/l with persistence of responsiveness to CRH; brain computed tomography showed a clearcut reduction of tumour size. One month after drug withdrawal, the tumour volume appeared unchanged and plasma ACTH values ranged between 374 and 440 pmol/l. One and a half year after drug withdrawal, a brain computed tomography showed re-expansion of the pituitary adenoma with evidence of suprasellar extension, which had never been seen previously. Plasma ACTH ranged between 113 and 199 pmol/l. A second course of sodium valproate was started; after three months, a brain computed tomography documented clearcut reduction of tumour volume from a suprasellar extension to a partially empty pituitary fossa. Plasma ACTH ranged from 396 to 542 pmol/l with persistence of responsiveness to CRH. The present report documents for the first time the reduction of tumour size in a patient with an ACTH-secreting macroadenoma by chronic administration of sodium valproate.

Use of ketoconazole in the treatment of Cushing's syndrome

The therapeutic value of ketoconazole for long term treatment of patients with Cushing's syndrome was studied. Seven patients with Cushing's disease and one with an adrenal adenoma received 600-800 mg/day ketoconazole for 3-13 months. Plasma ACTH, cortisol, and dehydroepiandrosterone sulfate levels and urinary cortisol, 17-ketosteroid, and tetrahydro-11-deoxycortisol excretion were determined periodically during the treatment period. Plasma ACTH and cortisol responses to CRH stimulation were determined before and during treatment. Rapid and subsequently persistent clinical improvement occurred in each patient; plasma dehydroepiandrosterone sulfate and urinary 17-ketosteroid and cortisol excretion decreased soon after the initiation of treatment, subsequently remaining normal or nearly so throughout the treatment period. Urinary tetrahydro-11-deoxycortisol excretion increased significantly. Plasma cortisol levels decreased. Plasma ACTH levels did not change, and individual plasma ACTH and cortisol increments in response to CRH were comparable before and during treatment. The cortisol response to insulin-induced hypoglycemia improved in one patient and was restored to normal in another. The seven patients tested recovered normal adrenal suppressibility in response to a low dose of dexamethasone during ketoconazole treatment. Ketoconazole is effective for long term control of hypercortisolism of either pituitary or adrenal origin. Its effect appears to be mediated by inhibition of adrenal 11 beta-hydroxylase and 17,20-lyase, and it, in some unknown way, prevents the expected rise in ACTH secretion in patients with Cushing's disease.

Transsphenoidal microsurgery for Cushing's disease

The study shows the results of transsphenoidal microsurgery in 23 patients with Cushing's disease (CD). Out of the 21 patients with tumour confined to the sella, 18 who had selective adenomectomy, and 1 who underwent total hypophysectomy had correction of hypercortisolism. None of the patients with extrasellar extension of the tumour was cured. In 2 cases no adenoma was found intra-operatively. Post-operative hypoadrenalism was documented in all the patients who remitted clinically. By 3-26 months after surgery, adequate cortisol secretion was found in 12 patients, nine of whom regained diurnal variation of cortisol secretion and ten cortisol responsiveness to hypoglycaemia; a normal or near normal response of cortisol to CRF was documented in 11 out of 17 patients tested. Thyroid and gonadal function was restored in all but two patients in clinical remission, whereas GH responsiveness to hypoglycaemia appeared impaired in 11. Two patients had recurrence of the disease 2 and 3 years, respectively, after successful adenomectomy. In our experience transsphenoidal selective adenomectomy is an effective treatment for most patients with CD; additional therapeutic approaches should be considered for patients bearing pituitary tumours with extrasellar extension, whose surgical outcome is often disappointing.

Lack of ACTH lowering effect of sodium valproate in patients with ACTH hypersecretion

The effect of an oral dose of 200 or 400 mg sodium valproate (DPA) on ACTH and cortisol secretion was assessed in 11 patients with Cushing's disease (3 bilaterally adrenalectomized), 3 patients with Nelson's syndrome and 6 patients with Addison's disease. In none of the patients examined DPA induced changes in ACTH (and cortisol) levels appreciably different from the fluctuations recorded after placebo administration. The effect of a long term administration of sodium valproate (600-1000 mg/day) was evaluated in 2 patients with active Cushing's disease and in 1 patient with Nelson's syndrome (3 weeks, 3, 9 months respectively); in the 2 patients with Cushing's disease ACTH and cortisol secretion, 17-hydroxy-corticosteroids (17-OHCS) urinary excretion did not change during DPA treatment. Similarly the cortisol response to hypoglycemia and the 17-OHCS urinary excretion after dexamethasone were not normalized. Long term DPA administration did not induce either clinical or hormonal modifications in the patient with Nelson's syndrome. These findings do not support the possibility that a deficiency of a GABAergic system plays a role in the pathogenesis of ACTH hypersecretion. DPA does not seem to be of therapeutical value in the medical management of Cushing's disease and Nelson's syndrome.

Cushing's disease and marked hyperprolactinemia in a patient with a pituitary macroadenoma: effectiveness of bromocriptine treatment

The case of a young boy bearing a pituitary PRL secreting adenoma (20-30,000 ng/ml) with the unusual association of clinical and endocrinological features of Cushing's disease successfully treated with bromocriptine is described. Brain computed tomography evidenced a huge pituitary adenoma leading to visual field defects and raised intracranial pressure. Due to the very large size of the tumor, which rendered the complete neurosurgical removal unlikely, medical treatment with bromocriptine (10 mg/day) was started. Follow-up for more than six months demonstrated an impressive reduction of tumor size, the lowering of prolactin levels into the normal range, the normalization of visual field, and the regression of both clinical and biochemical signs of hypercortisolism.

Inhibitory effect of cyproheptadine on ACTH secretion in patients with Addison's disease

In 14 patients with Addison's disease plasma levels of ACTH were studied after administration of a single oral dose (16 mg) of cyproheptadine. The drug administration was followed by an inhibition of ACTH release. These results support the view that cyproheptadine may exert an inhibitory effect on ACTH secretion in subjects whose corticosteroid feedback mechanism is normal. We hypothesize that the effect of cyproheptadine might be related to its anti-serotonin or anti-histaminergic action.

Effects of sulpiride induced hyperprolactinaemia in patients with Turner's syndrome

In order to evaluate the interference of prolactin (PRL) on some aspects of pituitary-gonadal derangement observed in patients with hyperprolactinaemic amenorrhoea (HA), a GnRH stimulation test (100 micrograms i.v.) was performed on twenty-one patients with hyperprolactinaemia without evidence of pituitary tumour and in nine subjects with Turner's syndrome (TS) before and after sulpiride administration (200 mg/day orally, for 3 months). In patients with HA an enhanced response of gonadotrophins to GnRH was observed. In patients with TS a further increase of the gonadotrophin hyper-responsiveness to the releasing hormone occurred when hyperprolactinaemia was induced by chronic sulpiride administration. Since, in these patients, appreciable ovarian steroidogenesis is lacking, a direct effect of the increased plasma PRL at the hypothalamo-pituitary level is likely. In hyperprolactinaemic amenorrhoea pituitary hyper-responsiveness may not be due to PRL effects on ovarian steroidogenesis.