Objective: During follow-up in cancer patients, adrenal lesions are frequently found by computer tomography imaging. In these patients, the frequency of subclinical Cushing's syndrome (SCS) has not been fully explored. The aim of the present study was to investigate the presence of SCS in cancer patients with adrenal lesions in comparison to patients with true adrenal incidentalomas.
Design: We studied 95 patients with adrenal lesions: 57 patients (group A, 20 males and 37 females) had a history of extra-adrenal malignancy and adrenal lesions were discovered during staging of the primary cancer, and 38 patients (group B, 6 males and 32 females) had adrenal incidentalomas. The two groups had similar BMI. All patients had unenhanced HU < 10 in computed tomography to ensure low risk of adrenal metastatic disease. Patients' morning plasma cortisol levels and ACTH were measured. An overnight 1 mg dexamethasone suppression test (ODST) was performed in all participants; in case of abnormal results, 24-h urine cortisol and the low-dose dexamethasone suppression test were additionally conducted. The cutoffs of morning cortisol values used for ODST were 1.8 and 5 μg/dl.
Results: When the cutoff of 1.8 μg/dl for suppressed morning cortisol was used, 42.1% of group A and 39.5% of group B had abnormal results (p = 0.95). By using the threshold of 5 μg/dl after ODST, 5.3% of group A and 13.2% of group B did not have suppressed cortisol levels with the 1 mg ODST (p = 0.18). The main factors found to influence suppressed cortisol levels after ODST in both groups were BMI and size of the adrenal lesion.
Conclusions: Patients with extra-adrenal malignancies and adrenal lesions had similar rates of subclinical hypercortisolemia compared to patients with true adrenal incidentalomas.
Keywords: Adrenal incidentalomas; Cancer; Subclinical hypercortisolism.