Carney complex predisposes to breast cancer: prospective study of 50 women

OBJECTIVE

Carney complex (CNC) is a rare genetic syndrome, mostly due to germline loss-of-function pathogenic variants in PRKAR1A. Carney complex includes pigmented skin lesions, cardiac myxomas, primary pigmented nodular adrenocortical dysplasia, and various breast benign tumors.

DESIGN

The present study was designed to describe the characteristics of breast lesions in CNC patients and their association with other manifestations of CNC and PRKAR1A genotype.

METHODS

A 3-year follow-up multicenter French prospective study of CNC patients included 50 women who were analyzed for CNC manifestations and particularly breast lesions, with breast imaging, genotyping, and hormonal settings.

RESULTS

Among the 38 women with breast imaging, 14 (39%) had breast lesions, half of them bilateral. Ten women (26%) presented with benign lesions and six with breast carcinomas (16%): one had ductal carcinoma in situ at 54, and five had invasive cancer before 50 years old, whom one with contralateral breast cancer during follow-up. The occurrence of breast cancer was more frequent in women with PRKAR1A pathogenic variant odds ratio = 6.34 (1.63-17.91) than in general population of same age. The mean age at breast cancer diagnosis was 44.7 years old: 17 years younger than in the general population. Breast cancer patients had good prognosis factors. All breast carcinomas occurred in individuals with familial CNC and PRKAR1A pathogenic variants. Loss of heterozygosity at the PRKAR1A locus in the 2 invasive breast carcinomas analyzed suggested a driver role of this tumor suppressor gene.

CONCLUSIONS

As CNC could predispose to breast carcinoma, an adequate screening strategy and follow-up should be discussed in affected women.

CLINICAL TRIAL REGISTRATION

ClinicalTrial.gov NCT00668291.

Association between endometriosis and risk of type 2 diabetes: Results from the prospective E3N cohort

OBJECTIVE

Several studies suggest an association between endometriosis and the risk of cardio-metabolic diseases. This study aimed to prospectively evaluate the association between history of endometriosis and incident type 2 diabetes.

STUDY DESIGN

E3N is a prospective cohort of 98,995 French women aged 40-65 years at inclusion. Multivariable Cox regression models were used to estimate hazard ratios and 95 % confidence intervals for the association between endometriosis and incident type 2 diabetes. We evaluated effect modification by age, body mass index, infertility treatment, adherence to the Mediterranean diet, and menopausal status.

RESULTS

Age at inclusion was 51 ± 6 years and there were 2672 incident cases of type 2 diabetes. A total of 4606 women reported surgically-confirmed endometriosis among 83,582 women with no history of diabetes at inclusion. Endometriosis was not associated with type 2 diabetes risk in a model adjusted for age, BMI, physical activity, smoking, education, age at menarche and oral contraceptive use (hazard ratio [HR] = 1.09; 95 % confidence interval [CI] = 0.92-1.29), neither after further adjustment for family history of diabetes, hypertension and menopausal status (HR = 0.97;95%CI = 0.80-1.16). The relationship did not differ by age at inclusion, BMI, infertility treatment, diet or menopausal status (p > 0.05).

CONCLUSIONS

Surgically-confirmed endometriosis was not associated with the risk of type 2 diabetes in this large cohort, confirming that endometriosis is not a risk marker for type 2 diabetes.

Thyrotoxic periodic paralysis associated with lactic metabolic acidosis: Case report of an African man and review of literature

BACKGROUND

Thyrotoxic periodic paralysis (TPP) is a rare and most often acquired subtype of hypokalemic periodic paralysis. The association of varying degrees of muscle weakness, hyperthyroidism and hypokalemia characterizes it. The treatment requires potassium supplementation, control of hyperthyroidism and prevention measures. It is a frequent disease in Asian men, but much rare in Caucasian or African populations. This is the first report of TPP associated with lactic metabolic acidosis in an African man.

CASE PRESENTATION

A 23 year-old African man, native from Morocco, with recurrent episodes of tetraparesis for eleven months, and abdominal pain, was referred for evaluation. Biochemical investigations showed severe hypokalemia associated with hyperthyroidism and lactic metabolic acidosis. His EKG showed signs of hypokalemia such as sinus tachycardia and U waves. After potassium supplementation, neurological recuperation was quick and complete. Thyroid ultrasound identified a hypoechogenic and hypervascularized goiter, associated with high levels of thyroid antibodies, in favor of Grave's disease. With antithyroid drugs and life-style changes, the patient did not have any other attack.

REVIEW OF LITERATURE

In addition to the case report, this article presents an extended review of literature, from the first large study reporting the diagnosis and incidence of TPP in 1957 to nowadays. Are reported here the latest information concerning epidemiology, clinical manifestations, complementary examinations, management and genetic finding. The lactic acidosis observed initially is exceptional, never described in TPP. TPP is a diagnostic and therapeutic emergency, requiring careful potassium supplementation, in order to avoid the risk of the onset of rebound hyperkalemia, to be maintained until the etiological treatment is effective. Paraclinical assessment with emergency EKG and electromyogram are essential to assess the impact.

DISCUSSION

It is essential in the face of any hypokalaemic periodic paralysis, including in non-Asian subjects, to search hyperthyroidism.

CONCLUSIONS

This report demonstrates the importance of thyroid testing in case of acute muscle weakness, even in non-Asian patients in order to diagnose TPP. This is a rare but possible etiology, to be distinguished from the familial form of hypokalemic periodic paralysis. It also questions on the impact of TPP on energetic metabolism, in particular on lactic metabolism.

OR12-3 Identification of Predictive Criteria for the Primary Bilateral Macronodular Adrenal Hyperplasia Gene ARMC5: A European Series of 352 Unselected Patients

Objective

Primary Bilateral Macronodular Adrenal Hyperplasia (PBMAH) is a heterogeneous disease characterized by adrenal macronodules and variable levels of cortisol excess, with not clearly established clinical diagnostic criteria. PBMAH can be caused by germline inactivating variants of the tumor suppressor gene ARMC5. We aimed to better characterize ARMC5-mutated and wild-type patients and to identify predictive criteria for ARMC5 variants.

Methods

We included 352 consecutive index patients from 12 European centers, sequenced for germline ARMC5alteration because of PBMAH suspicion, regardless their clinical presentation. Clinical, biological and imaging data were collected retrospectively. Sensitivity, specificity, negative and positive predictive values for the prediction of ARMC5variant were calculated for various parameters.

Results

53 patients (15.1%) carried 40 different ARMC5 germline pathogenic variants and showed a more distinct phenotype than non-mutated patients for cortisol excess (24-hour urinary free cortisol 2.32 vs. 1.11-fold ULN, respectively, p<0.001; plasma cortisol after 1 mg dexamethasone suppression test 337.5 vs. 142.4 nmol/L, respectively, p<0.001) and adrenal morphology (maximal adrenal diameter 104 vs. 83 mm, respectively, p<0.001; 9.8 vs. 3.2 adrenal nodules, respectively, p<0.001), with more frequent metabolic complications such as diabetes (51.0 vs. 35.4%, respectively, p=0.038) and hypertension (88.0 vs. 70.6%, respectively, p=0.014). Thus, ARMC5-mutated patients were more often surgically or medically treated in order to control cortisol excess (67.9 vs. 36.8%, respectively, p<0.001). Among operated patients, a bilateral adrenalectomy was more often performed in those carrying an ARMC5 pathogenic variant than in wild-type patients (56.7 vs. 32.3%, respectively, p=0.019). Even if all patients were more often primarily investigated in front of adrenal incidentaloma than clinical evidence for Cushing's syndrome (73 vs. 27%, respectively), ARMC5 patients were more often referred for Cushing's syndrome than wild-type patients (44 vs. 24%, respectively, p=0.004). To improve the ARMC5 mutation rate, the association of a clear bilateral adrenal involvement with evidence for autonomous cortisol secretion (defined at least by a plasma cortisol after 1 mg dexamethasone suppression test above 50 nmol/L) holds the better yield with a 27% specificity and a 20% positive predictive value, and a 100% sensitivity and negative predictive value, meaning that a useless genotyping could have been avoided for more than 20% of negative patients, without missing any mutated patient.

Conclusion

We report the largest series of index case patients investigated for ARMC5 with clinical characterization and confirm that ARMC5 pathogenic variants are associated with a more severe phenotype. In order to minimize negative ARMC5 screening, genotyping could be limited to clear bilateral adrenal involvement on imaging and autonomous cortisol secretion, with an optimum yield for routine clinical practice. These findings will also help better define PBMAH diagnostic criteria.

Presentation: Sunday, June 12, 2022 11:30 a.m. - 11:45 a.m.

OR04-3 Genetic Alterations of ARMC5 and KDM1A Are Associated With Different Expression Profiles of Illegitimate Receptors in Primary Bilateral Macronodular Adrenal Hyperplasia

Introduction

Primary Bilateral Macronodular Adrenal Hyperplasia (PBMAH) is a heterogeneous disease characterized by bilateral adrenal macronodules responsible for adrenal Cushing. To date, two genetic causes of PBMAH are known: germline inactivating variants of the tumor suppressor genes ARMC5 identified in 2013 (Assié, N Eng J Med 2013), responsible for 20 to 25% of index cases, and KDM1A, identified recently (Vaczlavik, GIM 2021; Chasseloup, Lancet D&E 2021), responsible for the rare presentation associated with food-dependent Cushing's syndrome (FDCS) due to aberrant expression of the GIP receptor (GIPR) in adrenocortical cells. Multiple other illegitimate receptors are known to be responsible for abnormal cortisol response to various physiological stimuli in PBMAH. A recent multiomic analysis, identified three distinct molecular PBMAH groups: G1 with ARMC5-mutated tumors, G2 with KDM1A-mutated tumors from FDCS patients, and G3 with no identified genetic cause at present. We aimed to identify specific expression profiles of illegitimate receptors in the three groups.

Methods

Based on the transcriptome data obtained by RNA sequencing (Illumina) of the tumors from 31 patients (G1/ARMC5, 16 patients; G2/KDM1A, 6 patients; G3, 9 patients), expression of the following genes, encoding potential illegitimate receptors, were compared: ADRA1A, ADRA1B, ADRA1D, ADRA2A, ADRA2B, ADRA2C, ADRB1, ADRB2, ADRB3, AVPR1A, AVPR1B, AVPR2, GCGR, GIPR, HTR4, HTR7, LHCGR. Calculations were performed using R statistical software. The Bioconductor limma package was used to analyze mRNA differential expression.

Results

G1/ARMC5 tumors showed a relative overexpression of the vasopressin receptors AVPR1A and AVPR1B compared to the two other groups (fold-change [FC] =7.39, p&lt;0.001 and 3.98, p&lt;0.001, respectively) but a lower expression of AVPR2 (FC=0.43, p=0.015). G2/KDM1A tumors showed a dramatic overexpression of GIPR compared to the two other groups (FC=105.02, p&lt;0.001) but also of the adrenergic receptors ADRA1D and ADRA2A (FC=2.93, p=0.027 and 9.99, p&lt;0.001, respectively) and of the LH/hCG receptor (LHCGR) (FC=12.20, p&lt;0.001). G3 tumors showed a slight overexpression of the adrenergic receptor ADRA1B (FC=3.49, p=0.001) and in few tumors ADRA1D, AVPR2 and LHCGR were highly expressed suggesting molecular heterogeneity in G3.

Conclusion

This study reveals specific expression profiles of illegitimate receptors related to the three molecular groups. ARMC5 tumors are associated with the overexpression of two vasopressin receptors, while, besides GIPR, KDM1A inactivation seems to drive the overexpression of the LH/hCG receptor, as previously suggested in patients with FDCS (Bertherat, JCE&M 2005), potentially responsible for Cushing's syndrome associated with pregnancy and menopause. These molecular patterns need to be corroborated by clinical data with a systematic testing of the aberrant cortisol responses. Additionally, further studies would be needed to investigate the clinical relevance and significance of moderate fold-changes in gene expression (e.g. &lt;4).

Presentation: Saturday, June 11, 2022 12:00 p.m. - 12:15 p.m.

Identification of predictive criteria for pathogenic variants of primary bilateral macronodular adrenal hyperplasia (PBMAH) gene ARMC5 in 352 unselected patients

OBJECTIVE

Primary bilateral macronodular adrenal hyperplasia (PBMAH) is a heterogeneous disease characterized by adrenal macronodules and variable levels of cortisol excess, with not clearly established clinical diagnostic criteria. It can be caused by ARMC5 germline pathogenic variants. In this study, we aimed to identify predictive criteria for ARMC5 variants.

METHODS

We included 352 consecutive index patients from 12 European centers, sequenced for germline ARMC5 alteration. Clinical, biological and imaging data were collected retrospectively.

RESULTS

52 patients (14.8%) carried ARMC5 germline pathogenic variants and showed a more distinct phenotype than non-mutated patients for cortisol excess (24-h urinary free cortisol 2.32 vs 1.11-fold ULN, respectively, P < 0.001) and adrenal morphology (maximal adrenal diameter 104 vs 83 mm, respectively, P < 0.001) and were more often surgically or medically treated (67.9 vs 36.8%, respectively, P < 0.001). ARMC5-mutated patients showed a constant, bilateral adrenal involvement and at least a possible autonomous cortisol secretion (defined by a plasma cortisol after 1 mg dexamethasone suppression above 50 nmol/L), while these criteria were not systematic in WT patients (78.3%). The association of these two criteria holds a 100% sensitivity and a 100% negative predictive value for ARMC5 pathogenic variant.

CONCLUSION

We report the largest series of index patients investigated for ARMC5 and confirm that ARMC5 pathogenic variants are associated with a more severe phenotype in most cases. To minimize negative ARMC5 screening, genotyping should be limited to clear bilateral adrenal involvement and autonomous cortisol secretion, with an optimum sensitivity for routine clinical practice. These findings will also help to better define PBMAH diagnostic criteria.

Molecular Basis of Primary Aldosteronism and Adrenal Cushing Syndrome

This review reports the main molecular alterations leading to development of benign cortisol- and/or aldosterone-secreting adrenal tumors. Causes of adrenal Cushing syndrome can be divided in 2 groups: multiple bilateral tumors or adenomas secreting cortisol. Bilateral causes are mainly primary pigmented nodular adrenocortical disease, most of the time due to PRKAR1A germline-inactivating mutations, and primary bilateral macronodular adrenal hyperplasia that can be caused in some rare syndromic cases by germline-inactivating mutations of MEN1, APC, and FH and of ARMC5 in isolated forms. PRKACA somatic-activating mutations are the main alterations in unilateral cortisol-producing adenomas. In primary hyperaldosteronism (PA), familial forms were identified in 1% to 5% of cases: familial hyperaldosteronism type I (FH-I) due to a chimeric CYP11B1/CYP11B2 hybrid gene, FH-II due to CLCN-2 germline mutations, FH-III due to KCNJ5 germline mutations, FH-IV due to CACNA1H germline mutations and PA, and seizures and neurological abnormalities syndrome due to CACNA1D germline mutations. Several somatic mutations have been found in aldosterone-producing adenomas in KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1 genes.

In addition to these genetic alterations, genome-wide approaches identified several new alterations in transcriptome, methylome, and miRnome studies, highlighting new pathways involved in steroid dysregulation.