Urine steroid metabolomics for the differential diagnosis of adrenal incidentalomas in the EURINE-ACT study: a prospective test validation study

BACKGROUND

Cross-sectional imaging regularly results in incidental discovery of adrenal tumours, requiring exclusion of adrenocortical carcinoma (ACC). However, differentiation is hampered by poor specificity of imaging characteristics. We aimed to validate a urine steroid metabolomics approach, using steroid profiling as the diagnostic basis for ACC.

METHODS

We did a prospective multicentre study in adult participants (age ≥18 years) with newly diagnosed adrenal masses. We assessed the accuracy of diagnostic imaging strategies based on maximum tumour diameter (≥4 cm vs <4 cm), imaging characteristics (positive vs negative), and urine steroid metabolomics (low, medium, or high risk of ACC), separately and in combination, using a reference standard of histopathology and follow-up investigations. With respect to imaging characteristics, we also assessed the diagnostic utility of increasing the unenhanced CT tumour attenuation threshold from the recommended 10 Hounsfield units (HU) to 20 HU.

FINDINGS

Of 2169 participants recruited between Jan 17, 2011, and July 15, 2016, we included 2017 from 14 specialist centres in 11 countries in the final analysis. 98 (4·9%) had histopathologically or clinically and biochemically confirmed ACC. Tumours with diameters of 4 cm or larger were identified in 488 participants (24·2%), including 96 of the 98 with ACC (positive predictive value [PPV] 19·7%, 95% CI 16·2-23·5). For imaging characteristics, increasing the unenhanced CT tumour attenuation threshold to 20 HU from the recommended 10 HU increased specificity for ACC (80·0% [95% CI 77·9-82·0] vs 64·0% [61·4-66.4]) while maintaining sensitivity (99·0% [94·4-100·0] vs 100·0% [96·3-100·0]; PPV 19·7%, 16·3-23·5). A urine steroid metabolomics result indicating high risk of ACC had a PPV of 34·6% (95% CI 28·6-41·0). When the three tests were combined, in the order of tumour diameter, positive imaging characteristics, and urine steroid metabolomics, 106 (5·3%) participants had the result maximum tumour diameter of 4 cm or larger, positive imaging characteristics (with the 20 HU cutoff), and urine steroid metabolomics indicating high risk of ACC, for which the PPV was 76·4% (95% CI 67·2-84·1). 70 (3·5%) were classified as being at moderate risk of ACC and 1841 (91·3%) at low risk (negative predictive value 99·7%, 99·4-100·0).

INTERPRETATION

An unenhanced CT tumour attenuation cutoff of 20 HU should replace that of 10 HU for exclusion of ACC. A triple test strategy of tumour diameter, imaging characteristics, and urine steroid metabolomics improves detection of ACC, which could shorten time to surgery for patients with ACC and help to avoid unnecessary surgery in patients with benign tumours.

FUNDING

European Commission, UK Medical Research Council, Wellcome Trust, and UK National Institute for Health Research, US National Institutes of Health, the Claire Khan Trust Fund at University Hospitals Birmingham Charities, and the Mayo Clinic Foundation for Medical Education and Research.

High-Resolution, Accurate-Mass (HRAM) Mass Spectrometry Urine Steroid Profiling in the Diagnosis of Adrenal Disorders

BACKGROUND

Steroid profiling is a promising diagnostic tool with adrenal tumors, Cushing syndrome (CS), and disorders of steroidogenesis. Our objective was to develop a multiple-steroid assay using liquid-chromatography, high-resolution, accurate-mass mass spectrometry (HRAM LC-MS) and to validate the assay in patients with various adrenal disorders.

METHODS

We collected 24-h urine samples from 114 controls and 71 patients with adrenal diseases. An HRAM LC-MS method was validated for quantitative analysis of 26 steroid metabolites in hydrolyzed urine samples. Differences in steroid excretion between patients were analyzed based on Z-score deviation from control reference intervals.

RESULTS

Limits of quantification were 20 ng/mL. Dilution linearity ranged from 80% to 120% with means of 93% to 110% for all but 2 analytes. Intraassay and interassay imprecision ranged from 3% to 18% for all but 1 analyte. Control women had lower excretion of androgen and glucocorticoid precursors/metabolites than men (P &lt; 0.001), but no difference in mineralocorticoids was seen (P = 0.06). Androgens decreased with age in both sexes (P &lt; 0.001). Compared with patients with adrenocortical adenoma (ACA), patients with adrenocortical carcinoma (ACC) had 11 steroids with increased Z scores, especially tetrahydro-11-deoxycortisol (14 vs 0.5, P &lt; 0.001), pregnanetriol (7.5 vs −0.4, P = 0.001), and 5-pregnenetriol (5.4 vs −0.4, P = 0.01). Steroid profiling also demonstrated metabolite abnormalities consistent with enzymatic defects in congenital adrenal hyperplasia and differences in pituitary vs adrenal CS.

CONCLUSIONS

Our HRAM LC-MS assay successfully quantifies 26 steroids in urine. The statistically significant differences in steroid production of ACC vs ACA, adrenal vs pituitary CS, and in congenital adrenal hyperplasia should allow for improved diagnosis of patients with these diseases.

Malignant Pheochromocytoma and Paraganglioma: 272 Patients Over 55 Years

CONTEXT

Malignant pheochromocytoma (PHEO) and paraganglioma (PGL) are rare and knowledge of the natural history is limited.

OBJECTIVE

We aimed to describe baseline characteristics and outcomes of patients with malignant PHEO and PGL (PPGL) and to identify predictors of shorter survival.

DESIGN

Retrospective review of patients with malignant PPGL evaluated from 1960 to 2016.

SETTING

Referral center.

PATIENTS

The group comprised 272 patients.

MAIN OUTCOME MEASURES

Baseline description, survival outcomes, and predictors of shorter survival were evaluated in patients with rapidly progressive (n = 29) and indolent disease (n = 188).

RESULTS

Malignant PPGL was diagnosed at a median age of 39 years (range, 7 to 83 years), with synchronous metastases in 96 (35%) patients. In 176 (65%) patients, metastases developed at a median of 5.5 years (range, 0.3 to 53.4 years) from the initial diagnosis. Median follow-up was 8.2 years (range, 0.01 to 54.1 years). Median overall and disease-specific survivals were 24.6 and 33.7 years, respectively. Shorter survival correlated with male sex (P = 0.014), older age at the time of primary tumor (P = 0.0011), synchronous metastases (P < 0.0001), larger primary tumor size (P = 0.0039), elevated dopamine (P = 0.0195), and not undergoing primary tumor resection (P < 0.0001). There was no difference in the type of primary tumor or presence of SDHB mutation.

CONCLUSIONS

The clinical course of patients with malignant PPGL is remarkably variable. Rapid disease progression is associated with male sex, older age at diagnosis, synchronous metastases, larger tumor size, elevated dopamine, and not undergoing resection of primary tumor. An individualized approach to patients with metastatic PPGL is warranted.