Update on the risks of benign adrenocortical incidentalomas

Is there a role for the IGF system and epidermal growth factor (EGF) in the pathogenesis of adrenocortical adenomas? A preliminary case-control study

Adrenal incidentalomas (AI) are very common and mostly they are non-functioning adenomas (NFA). NFAs are often associated with insulin resistance and metabolic syndrome. Several biomarkers, including certain growth factors, may participatein the pathogenesis ofmetabolic changes in patients with adrenal adenomas.Patients with NFA and age-matched control subjects were enrolled in the study. Data on age, gender, presence of metabolic syndrome or its components were obtained for each subject. Blood samples were obtained and glycemia, insulinemia, lipid profile, and selected growth factor levels were measured. Forty-three patients with NFA and 40 controls were included in the study. Differences were not found in the metabolic syndrome and its components prevalence or in the biochemical profile between patients and the control group. Significant differences were noticed in the levels of IGF1, IGF2, and IGFBP3 (p=0.016, p=0.005, p=0.004, respectively), but there were no differences in VEGF or EGF concentrations. In NFA patients, an association between glycemia and EGF levels was present (p=0.026). No significant correlations between tumor size and insulin or growth factor concentrations were present in AI patients. Significantly higher serum IGF1, IGF2, and IGFBP3 concentrations in NFA patients may support the role of the IGF axis in the pathogenesis of adrenocortical lesions.No correlation between IGFs or IGFBP3 and parameters of glucose or lipid metabolism was found. Present results may support the role of the growth hormone axis rather than hyperinsulinemia and insulin resistance in the pathogenesis of adrenocortical adenomas.

MIFEPRISTONE TREATMENT FOR MILD AUTONOMOUS CORTISOL SECRETION DUE TO ADRENAL ADENOMAS: A PILOT STUDY

Objective: Adrenal incidentalomas are increasingly detected with the widespread use of thoracic and abdominal imaging. The most common secretory syndrome in adrenal nodules is autonomous cortisol secretion (ACS). Recent data show that even mild cortisol excess is associated with adverse outcomes. The glucocorticoid receptor antagonist mifepristone has been used in patients with overt Cushing syndrome and hyperglycemia. The purpose of our study was to determine the effect of mifepristone on metabolic parameters in patients with ACS and concomitant prediabetes or diabetes. Methods: Eight patients with either unilateral or bilateral adrenal nodules with ACS were included in the study. Fasting laboratory tests including glucose and insulin levels to calculate homeostatic model assessment for insulin resistance (HOMA-IR) were performed at baseline and again after either 3 months (3 patients) or 6 months (5 patients) on mifepristone 300 mg daily treatment. Patients also completed several validated surveys on mood and quality of life at baseline and follow-up. Results: There were significant reductions in fasting glucose measurements and insulin resistance as measured by HOMA-IR in the 6 of 8 study patients in whom these measurements were available (P = .03). Conclusion: This pilot study demonstrates that mifepristone treatment of ACS is associated with a significant decrease in fasting glucose and insulin resistance as measured by HOMA-IR scores. Mifepristone treatment of ACS may be considered as a medical option for patients with ACS due to adrenal adenomas with concomitant abnormal glucose parameters in whom surgical removal is not being considered. Abbreviations: ACS = autonomous cortisol secretion; ACTH = adrenocorticotropic hormone; AI = adrenal incidentaloma; DHEAS = dehydroepiandrosterone sulfate; GR = glucocorticoid receptor; HbA1c = hemoglobin A1c; HOMA-IR = homeostatic model assessment for insulin resistance; ODT = overnight dexamethasone suppression test; QoL = quality of life; STAI = state trait anxiety inventory; TSH = thyroid stimulating hormone; UFC = urinary free cortisol.

Recent Advances on Subclinical Hypercortisolism

During the last 20 years, a significant body of literature has accumulated regarding subclinical hypercortisolism in patients with adrenal incidentalomas. Retrospective studies have indicated these patients have an increase in cardiovascular events and mortality. Current recommendations for patients with adrenal incidentalomas include an overnight low-dose dexamethasone suppression test and a thorough evaluation of cardiovascular and metabolic risk factors. Further hormonal testing and close monitoring are necessary in patients with incomplete suppression. Unilateral adrenalectomy may be beneficial in cases with abnormal suppression and comorbidities related to hypercortisolemia. Prospective studies are need for a better risk stratification and tailored therapy.

Increased mortality in patients with adrenal incidentalomas and autonomous cortisol secretion: a 13-year retrospective study from one center

PURPOSE

To compare long-term outcomes in patients with adrenal incidentalomas (AIs) with the response to a 1 mg overnight dexamethasone suppression test (DST).

METHODS

Consecutive patients with "non-functional" AIs (n = 365) were examined. Patients with overt hormone excess, adrenocortical cancer and known malignancy had been excluded. Patients were classified to normal cortisol secretion group (n = 204, DST ≤ 50 nmol/l), possible autonomous cortisol secretion group (n = 128, DST 51-138 nmol/l) and autonomous cortisol secretion group (n = 33, DST ≥ 138 nmol/l).

RESULTS

Thirty-seven patients (10.1%) deceased during the follow-up period (5.2 ± 2.3 years): 16(7.8%) in the non-secreting group (time from diagnosis to death: 3.9 ± 2.9 years), 15 in the possible autonomous cortisol secretion group (11.7%, 3.2 ± 1.8 years) and 6 in the autonomous cortisol secretion group (18.2%, 2.3 ± 1.5 years), respectively (P = 0.019). Multivariate analysis only found significant association with age and the tumour size but if cortisol levels post-DST were analysed as a continuous variable it was significant as well. All deaths in autonomous cortisol secretion group were due to cancer not related to adrenal glands. Hypertension, cardiovascular disease and medications were more common in the possible and autonomous cortisol secretion group, especially in the former. More bilateral AIs and larger AI size were found in the two latter groups.

CONCLUSIONS

Patients with autonomous cortisol secretion had higher mortality than those with non-functioning AIs though cortisol levels post-DST as a continuous variable, age and tumour size were better predictor of mortality. Cardiovascular disease and osteoporosis medication seemed more prevalent in the possible and autonomous cortisol secretion groups, especially in the former.