Sophie Schweitzer, Meik Kunz, Max Kurlbaum, Johannes Vey, Sabine Kendl, Timo Deutschbein, Stefanie Hahner, Martin Fassnacht, Thomas Dandekar and Matthias Kroiss
Current workup for the pre-operative distinction between frequent adrenocortical adenomas (ACAs) and rare but aggressive adrenocortical carcinomas (ACCs) combines imaging and biochemical testing. We here investigated the potential of plasma steroid hormone profiling by liquid chromatography tandem mass spectrometry (LC-MS/MS) for the diagnosis of malignancy in adrenocortical tumors.
Retrospective cohort study of prospectively collected EDTA-plasma samples in a single tertiary reference center.
Steroid hormone profiling by liquid chromatography tandem mass spectrometry (LC-MS/MS) in random plasma samples and logistic regression modeling.
Fifteen steroid hormones were quantified in 66 ACAs (29 males; M) and 42 ACC (15 M) plasma samples. Significantly higher abundances in ACC vs ACA were observed for 11-deoxycorticosterone, progesterone, 17-hydroxyprogesterone, 11-deoxycortisol, DHEA, DHEAS and estradiol (all P < 0.05). Maximal areas under the curve (AUC) for discrimination between ACA and ACC for single analytes were only 0.76 (estradiol) and 0.77 (progesterone), respectively. Logistic regression modeling enabled the discovery of diagnostic signatures composed of six specific steroids for male and female patients with AUC of 0.95 and 0.94, respectively. Positive predictive values in males and females were 92 and 96%, negative predictive values 90 and 86%, respectively.
This study in a large adrenal tumor patient cohort demonstrates the value of plasma steroid hormone profiling for diagnosis of ACC. Application of LC-MS/MS analysis and of our model may facilitate diagnosis of malignancy in non-expert centers. We propose to continuously evaluate and improve diagnostic accuracy of LC-MS/MS profiling by applying machine-learning algorithms to prospectively obtained steroid hormone profiles.
Matthias Kroiss, Dietmar Plonné, Sabine Kendl, Diana Schirmer, Cristina L Ronchi, Andreas Schirbel, Martina Zink, Constantin Lapa, Hartwig Klinker, Martin Fassnacht, Werner Heinz and Silviu Sbiera
Oral mitotane (o,p′-DDD) is a cornerstone of medical treatment for adrenocortical carcinoma (ACC).
Serum mitotane concentrations >14 mg/l are targeted for improved efficacy but not achieved in about half of patients. Here we aimed at a better understanding of intestinal absorption and lipoprotein association of mitotane and metabolites o,p′-dichlorodiphenylacetic acid (o,p′-DDA) and o,p′-dichlorodiphenyldichloroethane (o,p′-DDE).
Lipoproteins were isolated by ultracentrifugation from the chyle of a 29-year-old patient and serum from additional 14 ACC patients treated with mitotane. HPLC was applied for quantification of mitotane and metabolites. We assessed NCI–H295 cell viability, cortisol production, and expression of endoplasmic reticulum (ER) stress marker genes to study the functional consequences of mitotane binding to lipoproteins.
Chyle of the index patient contained 197 mg/ml mitotane, 53 mg/ml o,p′-DDA, and 51 mg/l o,p′-DDE. Of the total mitotane in serum, lipoprotein fractions contained 21.7±21.4% (VLDL), 1.9±0.8% (IDL), 8.9±5.5% (LDL1), 18.9±9.6% (LDL2), 10.1±4.0% (LDL3), and 26.3±13.0% (HDL2). Only 12.3±5.5% were in the lipoprotein-depleted fraction.
Mitotane content of lipoproteins directly correlated with their triglyceride and cholesterol content. O,p′-DDE was similarly distributed, but 87.9±4.2% of o,p′-DDA found in the HDL2 and lipoprotein-depleted fractions. Binding of mitotane to human lipoproteins blunted its anti-proliferative and anti-hormonal effects on NCI–H295 cells and reduced ER stress marker gene expression.
Mitotane absorption involves chylomicron binding. High concentrations of o,p′-DDA and o,p′-DDE in chyle suggest intestinal mitotane metabolism. In serum, the majority of mitotane is bound to lipoproteins. In vitro, lipoprotein binding inhibits activity of mitotane suggesting that lipoprotein-free mitotane is the therapeutically active fraction.