The mechanisms regulating cortisol production when ACTH of pituitary origin is suppressed in primary adrenal causes of Cushing's syndrome (CS) include diverse genetic and molecular mechanisms. These can lead either to constitutive activation of the cAMP system and steroidogenesis or to its regulation exerted by the aberrant adrenal expression of several hormone receptors, particularly G-protein coupled hormone receptors (GPCR) and their ligands. Screening for aberrant expression of GPCR in bilateral macronodular adrenal hyperplasia (BMAH) and unilateral adrenal tumors of patients with overt or subclinical CS demonstrates the frequent co-expression of several receptors. Aberrant hormone receptors can also exert their activity by regulating the paracrine secretion of ACTH or other ligands for those receptors in BMAH or unilateral tumors. The aberrant expression of hormone receptors is not limited to adrenal CS but can be implicated in other endocrine tumors including primary aldosteronism and Cushing's disease. Targeted therapies to block the aberrant receptors or their ligands could become useful in the future.
Nada El Ghorayeb, Isabelle Bourdeau, and André Lacroix
Terence J. McKenna, Daniel Lorber, Andre Lacroix, and David Rabin
Plasma testosterone levels were suppressed in 6 of 8 mature male patients with Cushing's disease, all of whom complained of loss of libido and decreased sexual potency. Gonadotrophin levels, both under basal conditions and in response to LH-RH, were generally normal. The testicular response to stimulation with hCG was brisk in the 2 patients examined. Oestradiol levels were slightly elevated in 2 patients and prolactin levels were normal in all patients. Thus, male patients with Cushing's disease demonstrated normal gonadotrophin levels in the presence of suppressed testosterone, or, viewed from a slightly different prospect, low testosterone levels despite normal gonadotrophins. Neither oestradiol nor prolactin excess appeared to account for the observations. Possible explanations for these findings include (a) a combination of impaired hypothalamic and testicular function, and (b) a resetting downwards of the level of testosterone that is seen as appropriate by the disordered hypothalamic-pituitary unit. Following correction of cortisol excess in Cushing's disease, testosterone levels rose into the normal range.
Isabelle Bourdeau, Nada El Ghorayeb, Nadia Gagnon, and André Lacroix
The investigation and management of unilateral adrenal incidentalomas have been extensively considered in the last decades. While bilateral adrenal incidentalomas represent about 15% of adrenal incidentalomas (AIs), they have been less frequently discussed. The differential diagnosis of bilateral incidentalomas includes metastasis, primary bilateral macronodular adrenal hyperplasia and bilateral cortical adenomas. Less frequent etiologies are bilateral pheochromocytomas, congenital adrenal hyperplasia (CAH), Cushing’s disease or ectopic ACTH secretion with secondary bilateral adrenal hyperplasia, primary malignancies, myelolipomas, infections or hemorrhage. The investigation of bilateral incidentalomas includes the same hormonal evaluation to exclude excess hormone secretion as recommended in unilateral AI, but diagnosis of CAH and adrenal insufficiency should also be excluded. This review is focused on the differential diagnosis, investigation and treatment of bilateral AIs.
Ariane Godbout, Marcos Manavela, Karina Danilowicz, Hugues Beauregard, Oscar Domingo Bruno, and André Lacroix
Cabergoline is a long-acting dopamine receptor agonist used to treat prolactinomas. Identification of D2 receptors in corticotroph tumors led to clinical trials of cabergoline therapy in limited cases of Nelson's syndrome, ectopic ACTH-secreting tumors, and recently Cushing's disease (CD).
To evaluate the long-term efficacy of cabergoline monotherapy in patients with CD.
Retrospective analysis of non-randomized clinical therapy with cabergoline in 30 patients with CD treated in academic centers of Buenos Aires and Montreal. Cabergoline was initiated at 0.5–1.0 mg/week and adjusted up to a maximal dose of 6 mg/week based on urinary free cortisol (UFC) levels. Complete response to cabergoline was defined as a sustained normalization of UFC with at least two normal values measured at 1–3 months interval; partial response was defined as a decrease of UFC to <125% of the upper limit of normal, and treatment failure as UFC ≥125% of it.
Within 3–6 months, complete response was achieved in 11 patients (36.6%) and partial response in 4 patients (13.3%). After long-term therapy, nine patients (30%) remain with a complete response after a mean of 37 months (range from 12 to 60 months) with a mean dose of 2.1 mg/week of cabergoline. Two patients escaped after 2 and 5 years of complete response, but one patient transiently renormalized UFC after an increase in cabergoline dosage. No long-term response was maintained in four initial partial responders.
Cabergoline monotherapy can provide an effective long-term medical therapy for selected patients with CD, but requires close follow-up for dose adjustments.
Sofia S Pereira, Mariana P Monteiro, Isabelle Bourdeau, André Lacroix, and Duarte Pignatelli
Adrenocortical carcinomas (ACCs) are rather rare endocrine tumors that often have a poor prognosis. The reduced survival rate associated with these tumors is due to their aggressive biological behavior, combined with the scarcity of effective treatment options that are currently available. The recent identification of the genomic alterations present in ACC have provided further molecular mechanisms to develop consistent strategies for the diagnosis, prevention of progression and treatment of advanced ACCs. Taken together, molecular and genomic advances could be leading the way to develop personalized medicine in ACCs similarly to similar developments in lung or breast cancers. In this review, we focused our attention to systematically compile and summarize the alterations in the cell cycle regulation that were described so far in ACC as they are known to play a crucial role in cell differentiation and growth. We have divided the analysis according to the major transition phases of the cell cycle, G1 to S and G2 to M. We have analyzed the most extensively studied checkpoints: the p53/Rb1 pathway, CDC2/cyclin B and topoisomerases (TOPs). We reached the conclusion that the most important alterations having a potential application in clinical practice are the ones related to p53/Rb1 and TOP 2. We also present a brief description of on-going clinical trials based on molecular alterations in ACC. The drugs have targeted the insulin-like growth factor receptor 1, TOP 2, polo-like kinase1, cyclin-dependent kinase inhibitors, p53 reactivation and CDC25.
Terence J. McKenna, Donald P. Island, Wendell E. Nicholson, Rebecca B. Miller, Andre Lacroix, and Grant W. Liddle
Acute stimulation of steroidogenesis with ACTH produces striking elevations in the plasma levels of cortisol as well as certain cortisol precursors. However, although states of chronic ACTH excess are characterized by similar elevations in cortisol, the precursor levels are in the low normal range. We have previously proposed that chronic stimulation of adrenal steroidogenesis with ACTH may enhance the activity of the late phase of cortisol biosynthesis. Precursor steroids would then be more efficiently used with less precursor leakage from the cell and greater cortisol production. In the present study, we have examined the effect of ACTH on the late phase of cortisol biosynthesis in vitro using bovine adrenal cell suspensions. To exclude the well established effect of ACTH on early cortisol biosynthetic steps we treated the cell suspensions with aminoglutethimide. This agent inhibits the conversion of cholesterol to pregnenolone and therefore to cortisol, both under basal conditions and during treatment with ACTH. To aminoglutethimide-treated cell suspensions, we added pregnenolone, 1 7-OH-pregnenolone, progesterone, 17-OH-progesterone and 11-deoxycortisol, with and without ACTH. In the presence of ACTH, significantly more cortisol was formed from progesterone, 17-OH-progesterone, and 11-deoxycortisol. To distinguish between effects of ACTH on the entry of precursors into cells and on enzyme activity within the cells, we examined the conversion of 11-deoxycortisol to cortisol in homogenized cell suspensions with and without pre-treatment with ACTH. Even in homogenized cells, prior treatment with ACTH enhanced the conversion of 11-deoxycortisol to cortisol. These findings clearly demonstrate that ACTH has a direct effect on the late phase of cortisol biosynthesis.
Marie-Josée Desrochers, Matthieu St-Jean, Nada El Ghorayeb, Isabelle Bourdeau, Benny So, Éric Therasse, Gregory Kline, and André Lacroix
Unilateral aldosteronomas should suppress renin and contralateral aldosterone secretion. Complete aldosterone suppression in contralateral adrenal vein sample (AVS) could predict surgical outcomes.
To retrospectively evaluate the prevalence of basal contralateral suppression using Aldosterone (A)contralateral(CL)/Aperipheral(P) as compared to (A/Cortisol(C)CL)/(A/C)P ratio in primary aldosteronism (PA) patients studied in two Canadian centers. To determine the best cut-off to predict clinical and biochemical surgical cure. To compare the accuracy of ACL/AP to the basal and post-ACTH lateralization index (LI) in predicting surgical cure.
In total, 330 patients with PA and successful AVS were included; 124 lateralizing patients underwent surgery. Clinical and biochemical cure at 3 and 12 months were evaluated using the PASO criteria.
Using ACL/AP and (A/C)CL/(A/C)P at the cut-off of 1, the prevalence of contralateral suppression was 6 and 45%, respectively. Using ROC curves, the ACL/AP ratio is associated with clinical cure at 3 and 12 months and biochemical cure at 12 months. (A/C)CL/(A/C)P is associated with biochemical cure only. The cut-offs for ACL/AP offering the best sensitivity (Se) and specificity (Sp) for clinical and biochemical cures at 12 months are 2.15 (Se: 63% and Sp: 71%) and 6.15 (Se: 84% and Sp: 77%), respectively. Basal LI and post-ACTH LI are associated with clinical cure but only the post-ACTH LI is associated with biochemical cure.
In lateralized PA, basal contralateral suppression defined by ACL/AP is rare and incomplete compared to the (A/C)CL/(A/C)P ratio and is associated with clinical and biochemical postoperative outcome, but with modest accuracy.
Mohamed-Karji Almarzooqi, Miguel Chagnon, Gilles Soulez, Marie-France Giroux, Patrick Gilbert, Vincent L Oliva, Pierre Perreault, Louis Bouchard, Isabelle Bourdeau, André Lacroix, and Eric Therasse
Many investigators believe that basal adrenal venous sampling (AVS) should be done simultaneously, whereas others opt for sequential AVS for simplicity and reduced cost. This study aimed to evaluate the concordance of sequential and simultaneous AVS methods.
Design and methods
Between 1989 and 2015, bilateral simultaneous sets of basal AVS were obtained twice within 5 min, in 188 consecutive patients (59 women and 129 men; mean age: 53.4 years). Selectivity was defined by adrenal-to-peripheral cortisol ratio ≥2, and lateralization was defined as an adrenal aldosterone-to-cortisol ratio ≥2, the contralateral side. Sequential AVS was simulated using right sampling at −5 min (t = −5) and left sampling at 0 min (t = 0).
There was no significant difference in mean selectivity ratio (P = 0.12 and P = 0.42 for the right and left sides respectively) and in mean lateralization ratio (P = 0.93) between t = −5 and t = 0. Kappa for selectivity between 2 simultaneous AVS was 0.71 (95% CI: 0.60–0.82), whereas it was 0.84 (95% CI: 0.76–0.92) and 0.85 (95% CI: 0.77–0.93) between sequential and simultaneous AVS at respectively −5 min and at 0 min. Kappa for lateralization between 2 simultaneous AVS was 0.84 (95% CI: 0.75–0.93), whereas it was 0.86 (95% CI: 0.78–0.94) and 0.80 (95% CI: 0.71–0.90) between sequential AVS and simultaneous AVS at respectively −5 min at 0 min.
Concordance between simultaneous and sequential AVS was not different than that between 2 repeated simultaneous AVS in the same patient. Therefore, a better diagnostic performance is not a good argument to select the AVS method.
Isabelle Bourdeau, Sylvie Oble, Fabien Magne, Isabelle Lévesque, Katia Y Cáceres-Gorriti, Serge Nolet, Philip Awadalla, Johanne Tremblay, Pavel Hamet, Maria Candida Barisson Villares Fragoso, and André Lacroix
Bilateral macronodular adrenal hyperplasia (BMAH) is a rare cause of Cushing's syndrome (CS) and its familial clustering has been described previously. Recent studies identified that ARMC5 mutations occur frequently in BMAH, but the relation between ARMC5 mutation and the expression of aberrant G-protein-coupled receptor has not been examined in detail yet.
We studied a large French-Canadian family with BMAH and sub-clinical or overt CS. Screening was performed using the 1-mg dexamethasone suppression test (DST) in 28 family members. Screening for aberrant regulation of cortisol by various hormone receptors were examined in vivo in nine individuals. Sequencing of the coding regions of ARMC5 gene was carried out.
Morning ambulating cortisol post 1 mg DST were >50 nmol/l in 5/8 members in generation II (57–68 years old), 9/22 in generation III (26–46 years old). Adrenal size was enlarged at different degrees. All affected patients increased cortisol following upright posture, insulin-induced hypoglycemia and/or isoproterenol infusion. β-blockers led to the reduction of cortisol secretion in all patients with the exception of two who had adrenalectomies because of β-blockers intolerance. We identified a heterozygous germline variant in the ARMC5 gene c.327_328insC, (p.Ala110Argfs*9) in nine individuals with clinical or subclinical CS, in four out of six individuals with abnormal suppression to dexamethasone at initial investigation and one out of six individuals with current normal clinical screening tests.
Systematic screening of members of the same family with hereditary BMAH allows the diagnosis of unsuspected subclinical CS associated with early BMAH. The relation between the causative ARMC5 mutation and the reproducible pattern of aberrant β-adrenergic and V1-vasopressin receptors identified in this family remains to be elucidated.
John Newell-Price, Rosario Pivonello, Antoine Tabarin, Maria Fleseriu, Przemysław Witek, Mônica R Gadelha, Stephan Petersenn, Libuse Tauchmanova, Shoba Ravichandran, Pritam Gupta, André Lacroix, and Beverly M K Biller
Monitoring of patients with Cushing’s disease on cortisol-lowering drugs is usually performed with urinary free cortisol (UFC). Late-night salivary cortisol (LNSC) has an established role in screening for hypercortisolism and can help to detect the loss of cortisol circadian rhythm. Less evidence exists regarding the usefulness of LNSC in monitoring pharmacological response in Cushing’s disease.
Exploratory analysis evaluating LNSC during a Phase III study of long-acting pasireotide in Cushing’s disease (clinicaltrials.gov: NCT01374906).
Mean LNSC (mLNSC) was calculated from two samples, collected on the same days as the first two of three 24-h urine samples (used to calculate mean UFC [mUFC]). Clinical signs of hypercortisolism were evaluated over time.
At baseline, 137 patients had evaluable mLNSC measurements; 91.2% had mLNSC exceeding the upper limit of normal (ULN; 3.2 nmol/L). Of patients with evaluable assessments at month 12 (n = 92), 17.4% had both mLNSC ≤ULN and mUFC ≤ULN; 22.8% had mLNSC ≤ULN, and 45.7% had mUFC ≤ULN. There was high variability in LNSC (intra-patient coefficient of variation (CV): 49.4%) and UFC (intra-patient CV: 39.2%). mLNSC levels decreased over 12 months of treatment and paralleled changes in mUFC. Moderate correlation was seen between mLNSC and mUFC (Spearman’s correlation: ρ = 0.50 [all time points pooled]). Greater improvements in systolic/diastolic blood pressure and weight were seen in patients with both mLNSC ≤ULN and mUFC ≤ULN.
mUFC and mLNSC are complementary measurements for monitoring treatment response in Cushing’s disease, with better clinical outcomes seen for patients in whom both mUFC and mLNSC are controlled.