Vasileios Chortis

Mitotane Therapy in Adrenocortical Cancer Induces CYP3A4 and Inhibits 5α-Reductase, Explaining the Need for Personalized Glucocorticoid and Androgen Replacement

CONTEXT Mitotane [1-(2-chlorophenyl)-1-(4-chlorophenyl)-2,2-dichloroethane] is the first-line treatment for metastatic adrenocortical carcinoma (ACC) and is also regularly used in the adjuvant setting after presumed complete removal of the primary tumor. Mitotane is considered an adrenolytic substance, but there is limited information on distinct effects on steroidogenesis. However, adrenal insufficiency and male hypogonadism are widely recognized side effects of mitotane treatment. OBJECTIVE Our objective was to define the impact of mitotane treatment on in vivo steroidogenesis in patients with ACC. SETTING AND DESIGN At seven European specialist referral centers for adrenal tumors, we analyzed 24-h urine samples (n = 127) collected from patients with ACC before and during mitotane therapy in the adjuvant setting (n = 23) or for metastatic ACC (n = 104). Urinary steroid metabolite excretion was profiled by gas chromatography/mass spectrometry in comparison with healthy controls (n = 88). RESULTS We found a sharp increase in the excretion of 6β-hydroxycortisol over cortisol (P < 0.001), indicative of a strong induction of the major drug-metabolizing enzyme cytochrome P450 3A4. The contribution of 6β-hydroxycortisol to total glucocorticoid metabolites increased from 2% (median, interquartile range 1-4%) to 56% (39-71%) during mitotane treatment. Furthermore, we documented strong inhibition of systemic 5α-reductase activity, indicated by a significant decrease in 5α-reduced steroids, including 5α-tetrahydrocortisol, 5α-tetrahydrocorticosterone, and androsterone (all P < 0.001). The degree of inhibition was similar to that in patients with inactivating 5α-reductase type 2 mutations (n = 23) and patients receiving finasteride (n = 5), but cluster analysis of steroid data revealed a pattern of inhibition distinct from these two groups. Longitudinal data showed rapid onset and long-lasting duration of the observed effects. CONCLUSIONS Cytochrome P450 3A4 induction by mitotane results in rapid inactivation of more than 50% of administered hydrocortisone, explaining the need for doubling hydrocortisone replacement in mitotane-treated patients. Strong inhibition of 5α-reductase activity is in line with the clinical observation of relative inefficiency of testosterone replacement in mitotane-treated men, calling for replacement by 5α-reduced androgens.

Steroid metabolome analysis reveals prevalent glucocorticoid excess in primary aldosteronism

BACKGROUND. Adrenal aldosterone excess is the most common cause of secondary hypertension and is associated with increased cardiovascular morbidity. However, adverse metabolic risk in primary aldosteronism extends beyond hypertension, with increased rates of insulin resistance, type 2 diabetes, and osteoporosis, which cannot be easily explained by aldosterone excess. METHODS. We performed mass spectrometry–based analysis of a 24-hour urine steroid metabolome in 174 newly diagnosed patients with primary aldosteronism (103 unilateral adenomas, 71 bilateral adrenal hyperplasias) in comparison to 162 healthy controls, 56 patients with endocrine inactive adrenal adenoma, 104 patients with mild subclinical, and 47 with clinically overt adrenal cortisol excess. We also analyzed the expression of cortisol-producing CYP11B1 and aldosterone-producing CYP11B2 enzymes in adenoma tissue from 57 patients with aldosterone-producing adenoma, employing immunohistochemistry with digital image analysis. RESULTS. Primary aldosteronism patients had significantly increased cortisol and total glucocorticoid metabolite excretion (all P < 0.001), only exceeded by glucocorticoid output in patients with clinically overt adrenal Cushing syndrome. Several surrogate parameters of metabolic risk correlated significantly with glucocorticoid but not mineralocorticoid output. Intratumoral CYP11B1 expression was significantly associated with the corresponding in vivo glucocorticoid excretion. Unilateral adrenalectomy resolved both mineralocorticoid and glucocorticoid excess. Postoperative evidence of adrenal insufficiency was found in 13 (29%) of 45 consecutively tested patients. CONCLUSION. Our data indicate that glucocorticoid cosecretion is frequently found in primary aldosteronism and contributes to associated metabolic risk. Mineralocorticoid receptor antagonist therapy alone may not be sufficient to counteract adverse metabolic risk in medically treated patients with primary aldosteronism. FUNDING. Medical Research Council UK, Wellcome Trust, European Commission.

MANAGEMENT OF ENDOCRINE DISEASE: Imaging for the diagnosis of malignancy in incidentally discovered adrenal masses: a systematic review and meta-analysis.

Objective Adrenal masses are incidentally discovered in 5% of CT scans. In 2013/2014, 81 million CT examinations were undertaken in the USA and 5 million in the UK. However, uncertainty remains around the optimal imaging approach for diagnosing malignancy. We aimed to review the evidence on the accuracy of imaging tests for differentiating malignant from benign adrenal masses. Design A systematic review and meta-analysis was conducted. Methods We searched MEDLINE, EMBASE, Cochrane CENTRAL Register of Controlled Trials, Science Citation Index, Conference Proceedings Citation Index, and ZETOC (January 1990 to August 2015). We included studies evaluating the accuracy of CT, MRI, or 18F-fluoro-deoxyglucose (FDG)-PET compared with an adequate histological or imaging-based follow-up reference standard. Results We identified 37 studies suitable for inclusion, after screening 5469 references and 525 full-text articles. Studies evaluated the accuracy of CT (n=16), MRI (n=15), and FDG-PET (n=9) and were generally small and at high or unclear risk of bias. Only 19 studies were eligible for meta-analysis. Limited data suggest that CT density >10HU has high sensitivity for detection of adrenal malignancy in participants with no prior indication for adrenal imaging, that is, masses with ≤10HU are unlikely to be malignant. All other estimates of test performance are based on too small numbers. Conclusions Despite their widespread use in routine assessment, there is insufficient evidence for the diagnostic value of individual imaging tests in distinguishing benign from malignant adrenal masses. Future research is urgently needed and should include prospective test validation studies for imaging and novel diagnostic approaches alongside detailed health economics analysis.

THERAPY OF ENDOCRINE DISEASE: Improvement of cardiovascular risk factors after adrenalectomy in patients with adrenal tumors and subclinical Cushing’s syndrome: a systematic review and meta-analysis

OBJECTIVE Beneficial effects of adrenalectomy on cardiovascular risk factors in patients with subclinical Cushings syndrome (SCS) are uncertain. We sought to conduct a systematic review and meta-analysis with the following objectives: (i) determine the effect of adrenalectomy compared with conservative management on cardiovascular risk factors in patients with SCS and (ii) compare the effect of adrenalectomy on cardiovascular risk factors in patients with SCS vs those with a nonfunctioning (NF) adrenal tumor. METHODS MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trial were searched on 17 November 2015. Reviewers extracted data and assessed methodological quality in duplicate. RESULTS We included 26 studies reporting on 584 patients with SCS and 457 patients with NF adrenal tumors. Studies used different definitions of SCS. Patients with SCS undergoing adrenalectomy demonstrated an overall improvement in cardiovascular risk factors (61% for hypertension, 52% for diabetes mellitus, 45% for obesity and 24% for dyslipidemia). When compared with conservative management, patients with SCS undergoing adrenalectomy experienced improvement in hypertension (RR 11, 95% CI: 4.3-27.8) and diabetes mellitus (RR 3.9, 95% CI: 1.5-9.9), but not dyslipidemia (RR 2.6, 95% CI: 0.97-7.2) or obesity (RR 3.4, 95% CI: 0.95-12). Patients with NF adrenal tumors experienced improvement in hypertension (21/54 patients); however, insufficient data exist for comparison to patients with SCS. CONCLUSIONS Available low-to-moderate-quality evidence from heterogeneous studies suggests a beneficial effect of adrenalectomy on cardiovascular risk factors in patients with SCS overall and compared with conservative management.

NNT is a key regulator of adrenal redox homeostasis and steroidogenesis in male mice.

Nicotinamide nucleotide transhydrogenase, NNT, is a ubiquitous protein of the inner mitochondrial membrane with a key role in mitochondrial redox balance. NNT produces high concentrations of NADPH for detoxification of reactive oxygen species by glutathione and thioredoxin pathways. In humans, NNT dysfunction leads to an adrenal-specific disorder, glucocorticoid deficiency. Certain substrains of C57BL/6 mice contain a spontaneously occurring inactivating Nnt mutation and display glucocorticoid deficiency along with glucose intolerance and reduced insulin secretion. To understand the underlying mechanism(s) behind the glucocorticoid deficiency, we performed comprehensive RNA-seq on adrenals from wild-type (C57BL/6N), mutant (C57BL/6J) and BAC transgenic mice overexpressing Nnt (C57BL/6JBAC). The following results were obtained. Our data suggest that Nnt deletion (or overexpression) reduces adrenal steroidogenic output by decreasing the expression of crucial, mitochondrial antioxidant (Prdx3 and Txnrd2) and steroidogenic (Cyp11a1) enzymes. Pathway analysis also revealed upregulation of heat shock protein machinery and haemoglobins possibly in response to the oxidative stress initiated by NNT ablation. In conclusion, using transcriptomic profiling in adrenals from three mouse models, we showed that disturbances in adrenal redox homeostasis are mediated not only by under expression of NNT but also by its overexpression. Further, we demonstrated that both under expression or overexpression of NNT reduced corticosterone output implying a central role for it in the control of steroidogenesis. This is likely due to a reduction in the expression of a key steroidogenic enzyme, Cyp11a1, which mirrored the reduction in corticosterone output.

Supine or sitting? Economic considerations regarding patient position during plasma metanephrine analysis for the exclusion of chromaffin tumours

Dear Editor, We have read the article ‘Biochemical diagnosis of phaeochromocytoma using plasma-free normetanephrine, metanephrine and methoxytyramine: importance of supine sampling under fasting conditions’ by Darr et al. with great interest. We concur with the importance of using reference ranges derived from supine, fasting patients to ensure a high diagnostic sensitivity for the detection of phaeochromocytomas/paragangliomas (PPGL). However, despite the demonstrated improved specificity, we believe that adopting measurement of plasma metanephrines in fasted patients in the supine position as a first-line diagnostic screening approach would not be practical in modern healthcare provision due to its substantial financial implications. We reviewed all plasma metanephrine results from patients requiring exclusion of PPGL due to presentation with a new adrenal lesion (n = 55) who attended our service at the University Hospital Birmingham during 2013. The vast majority of cases were adrenal incidentalomas (n = 48); in the remainder, the lesion was discovered in the context of regular monitoring for succinate dehydrogenase (SDH) or von Hippel–Lindau (VHL) gene mutations (n = 3), work-up for Cushing’s syndrome (n = 2) or postoperative follow-up imaging of previous extra-adrenal malignancy (n = 2). According to our local protocol, these patients are screened for PPGL with one plasma sample for metanephrines taken without special preparation, in the nonfasted state and sitting position on the day of their first clinic attendance. If plasma metanephrines determined under these conditions are elevated, repeat testing in the fasting state and after 30 min in the supine position is arranged by the endocrine specialist nurses. Of the 55 patients tested, seven (13%) had positive test results under sitting/ nonfasting conditions, that is increased above a reference range derived from healthy controls with samples collected in the supine/fasted state. Three of seven with plasma normetanephrine and/or metanephrine values >4-fold of the reference range were conclusively diagnosed with PPGL and not retested. The four remaining patients underwent repeat testing under supine/fasting conditions, revealing persistently increased plasma metanephrines in three of them, eventually diagnosed with phaeochromocytoma. Only one patient with borderline elevated plasma metanephrines in the sitting/nonfasting state was confirmed to have had a falsepositive result on initial screening, with the repeat test under supine/fasting conditions demonstrating normal plasma metanephrines (Table 1). Our screening under sitting/nonfasted conditions yielded a sensitivity of 86% (due to one case of a nonsecreting paraganglioma) and specificity of 98% for diagnosing chromaffin tumours; the overall prevalence of PPGL in our population was 11%. Blood samples for plasma metanephrines in the sitting and nonfasting state can be conveniently collected in the context of the first outpatient clinic visit and incurs a cost of £40 (£38 for biochemical analysis plus £2 phlebotomy costs). Conversely, supine/fasting sampling requires an extra visit to a nurse-led endocrinology outpatient clinic as a hospital day case, which incurs a total cost of £583 (£545 day case cost plus £38 for biochemical analysis). The overall cost of plasma metanephrine testing for the year 2013 in our department amounted to £4532. Adopting supine/fasting sampling as first-line investigation in all patients would inflate the total annual cost to £32 065, accruing an additional expenditure of £27 533. We acknowledge the fact that the cost of supine sampling may vary significantly from centre to centre but it would always exceed the cost of routine phlebotomy carried out in a one-stop approach during the routine clinic visit. Consequently, the strategy we propose will be

Primary adrenal insufficiency is associated with impaired natural killer cell function: A potential link to increased mortality

Objective Mortality in patients with primary adrenal insufficiency (PAI) is significantly increased, with respiratory infections as a major cause of death. Moreover, patients with PAI report an increased rate of non-fatal infections. Neutrophils and natural killer (NK) cells are innate immune cells that provide frontline protection against invading pathogens. Thus, we compared the function and phenotype of NK cells and neutrophils isolated from PAI patients and healthy controls to ascertain whether altered innate immune responses could be a contributory factor for the increased susceptibility of PAI patients to infection. Design and methods We undertook a cross-sectional study of 42 patients with PAI due to autoimmune adrenalitis (n = 37) or bilateral adrenalectomy (n = 5) and 58 sex- and age-matched controls. A comprehensive screen of innate immune function, consisting of measurements of neutrophil phagocytosis, reactive oxygen species production, NK cell cytotoxicity (NKCC) and NK cell surface receptor expression, was performed on all subjects. Results Neutrophil function did not differ between PAI and controls. However, NKCC was significantly reduced in PAI (12.0 ± 1.5% vs 21.1 ± 2.6%, P < 0.0001). Phenotypically, the percentage of NK cells expressing the activating receptors NKG2D and NKp46 was significantly lower in PAI, as was the surface density of NKG2D (all P < 0.0001). Intracellular granzyme B expression was significantly increased in NK cells from PAI patients (P < 0.01). Conclusions Adrenal insufficiency is associated with significantly decreased NKCC, thereby potentially compromising early recognition and elimination of virally infected cells. This potential impairment in anti-viral immune defense may contribute to the increased rate of respiratory infections and ultimately mortality in PAI.

Bilateral testicular tumors resulting in recurrent Cushing’s syndrome after bilateral adrenalectomy”

Context: Recurrence of hypercortisolism in patients after bilateral adrenalectomy for Cushing disease is extremely rare. Patient: We present a 27-year-old man who previously underwent bilateral adrenalectomy for Cushing disease with complete clinical resolution. Cushingoid features recurred 12 years later, with bilateral testicular enlargement. Hormonal tests confirmed adrenocorticotropic hormone (ACTH)-dependent Cushing disease. Surgical resection of the testicular tumors led to clinical and biochemical remission. Design and Results: Gene expression analysis of the tumor tissue by quantitative polymerase chain reaction showed high expression of all key steroidogenic enzymes. Adrenocortical-specific genes were 5.1 × 105 (CYP11B1), 1.8 × 102 (CYP11B2), and 6.3 × 104 (MC2R) times higher than nonsteroidogenic fibroblast control. This correlated with urine steroid metabolome profiling showing 2 fivefold increases in the excretion of the metabolites of 11-deoxycortisol, 21-deoxycortisol, and total glucocorticoids. Leydig-specific genes were 4.3 × 101 (LHCGR) and 9.3 × 100 (HSD17B3) times higher than control, and urinary steroid profiling showed twofold increased excretion of the major androgen metabolites androsterone and etiocholanolone. These distinctly increased steroid metabolites were suppressed by dexamethasone but unresponsive to human chorionic gonadotropin stimulation, supporting the role of ACTH, but not luteinizing hormone, in regulating tumor-specific steroid excess. Conclusion: We report bilateral testicular tumors occurring in a patient with recurrent Cushing disease 12 years after bilateral adrenalectomy. Using mRNA expression analysis and steroid metabolome profiling, the tumors demonstrated both adrenocortical and gonadal steroidogenic properties, similar to testicular adrenal rest tumors found in patients with congenital adrenal hyperplasia, suggesting the presence of pluripotent cells even in patients without congenital adrenal hyperplasia.

Improvement of cardiovascular risk factors after adrenalectomy in patients with adrenal tumors and subclinical Cushing's syndrome: A systematic review and meta-Analysis

OBJECTIVE Beneficial effects of adrenalectomy on cardiovascular risk factors in patients with subclinical Cushings syndrome (SCS) are uncertain. We sought to conduct a systematic review and meta-analysis with the following objectives: (i) determine the effect of adrenalectomy compared with conservative management on cardiovascular risk factors in patients with SCS and (ii) compare the effect of adrenalectomy on cardiovascular risk factors in patients with SCS vs those with a nonfunctioning (NF) adrenal tumor. METHODS MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trial were searched on 17 November 2015. Reviewers extracted data and assessed methodological quality in duplicate. RESULTS We included 26 studies reporting on 584 patients with SCS and 457 patients with NF adrenal tumors. Studies used different definitions of SCS. Patients with SCS undergoing adrenalectomy demonstrated an overall improvement in cardiovascular risk factors (61% for hypertension, 52% for diabetes mellitus, 45% for obesity and 24% for dyslipidemia). When compared with conservative management, patients with SCS undergoing adrenalectomy experienced improvement in hypertension (RR 11, 95% CI: 4.3-27.8) and diabetes mellitus (RR 3.9, 95% CI: 1.5-9.9), but not dyslipidemia (RR 2.6, 95% CI: 0.97-7.2) or obesity (RR 3.4, 95% CI: 0.95-12). Patients with NF adrenal tumors experienced improvement in hypertension (21/54 patients); however, insufficient data exist for comparison to patients with SCS. CONCLUSIONS Available low-to-moderate-quality evidence from heterogeneous studies suggests a beneficial effect of adrenalectomy on cardiovascular risk factors in patients with SCS overall and compared with conservative management.

THERAPY OF ENDOCRINE DISEASE: Improvement of cardiovascular risk factors after adrenalectomy in patients with adrenal tumors and Subclinical Cushing Syndrome: a systematic review and meta-analysis.

OBJECTIVE Beneficial effects of adrenalectomy on cardiovascular risk factors in patients with subclinical Cushings syndrome (SCS) are uncertain. We sought to conduct a systematic review and meta-analysis with the following objectives: (i) determine the effect of adrenalectomy compared with conservative management on cardiovascular risk factors in patients with SCS and (ii) compare the effect of adrenalectomy on cardiovascular risk factors in patients with SCS vs those with a nonfunctioning (NF) adrenal tumor. METHODS MEDLINE In-Process & Other Non-Indexed Citations, MEDLINE, EMBASE and Cochrane Central Register of Controlled Trial were searched on 17 November 2015. Reviewers extracted data and assessed methodological quality in duplicate. RESULTS We included 26 studies reporting on 584 patients with SCS and 457 patients with NF adrenal tumors. Studies used different definitions of SCS. Patients with SCS undergoing adrenalectomy demonstrated an overall improvement in cardiovascular risk factors (61% for hypertension, 52% for diabetes mellitus, 45% for obesity and 24% for dyslipidemia). When compared with conservative management, patients with SCS undergoing adrenalectomy experienced improvement in hypertension (RR 11, 95% CI: 4.3-27.8) and diabetes mellitus (RR 3.9, 95% CI: 1.5-9.9), but not dyslipidemia (RR 2.6, 95% CI: 0.97-7.2) or obesity (RR 3.4, 95% CI: 0.95-12). Patients with NF adrenal tumors experienced improvement in hypertension (21/54 patients); however, insufficient data exist for comparison to patients with SCS. CONCLUSIONS Available low-to-moderate-quality evidence from heterogeneous studies suggests a beneficial effect of adrenalectomy on cardiovascular risk factors in patients with SCS overall and compared with conservative management.