AD18 Integrated steroidomic and untargeted metabolomic profiling reveals distinct circulating signatures of adrenocortical carcinoma
Adrenal tumours display marked biological heterogeneity, making the distinction between benign and malignant lesions challenging. Liquid chromatography–high-resolution mass spectrometry (LC-HRMS) enables simultaneous investigation of steroidomic and broader metabolomic alterations. To identify integrated circulating steroidomic and metabolomic signatures associated with adrenocortical carcinoma (ACC), lipid-poor adenomas (LPAs), and lipid-rich adenomas (LRAs). Basal serum samples were collected from patients with ACC (n = 33), LPA (n = 68), and LRA (n = 166). Following protein precipitation and solid-phase extraction, 100 μL of serum was analysed using an in-house LC-HRMS method on the Orbitrap Exploris 240 platform (Thermo Fisher Scientific). Targeted absolute quantification was performed for 45 adrenal steroids, while full-scan acquisitions were processed using Compound Discoverer software for untargeted metabolite identification. Thirty-one steroids were detected, of which 14 differed significantly among the study groups. Untargeted analysis identified 806 features with annotation confidence >80%, including 34 endogenous metabolites with significant discriminatory value. Compared with LRA and LPA, ACC was characterized by significantly higher concentrations of pregnenolone, 17-hydroxypregnenolone, progesterone, 17-hydroxyprogesterone, 16-hydroxyprogesterone, 11β-hydroxyprogesterone, 11-deoxycorticosterone, 11-deoxycortisol, androstenedione, allopregnanolone, and dehydroepiandrosterone sulfate (DHEAS) (P < 0.001–0.034). ACC was also associated with increased arachidonic acid, docosahexaenoic acid, and several oxylipins, including hydroxyeicosatetraenoic acids, leukotriene derivatives, and resolvin D4 (all P < 0.001). In contrast, LPAs demonstrated higher aldosterone and 20β-dihydrocortisone concentrations, together with lower α-linolenoyl ethanolamide and glycerolipid levels than LRAs (all P < 0.007). Adrenocortical carcinoma exhibits a distinct circulating molecular signature characterized by dysregulated steroidogenesis together with enhanced lipid oxidation and inflammatory signalling. Although LPAs and LRAs showed largely overlapping metabolic profiles, several discriminatory biomarkers were identified. Integration of steroidomic and metabolomic profiling may improve the characterization of adrenal lesions and facilitate the identification of ACC.