A strategy that includes a urine steroid test along with imaging characteristics and tumor size criteria can significantly improve the challenging diagnosis of adrenocortical cancer, helping to avoid unnecessary, and often unsuccessful, further imaging and even surgery, new research shows.
“A triple-test strategy of tumor diameter, imaging characteristics, and urine steroid metabolomics improves detection of adrenocortical carcinoma, which could shorten time to surgery for patients with ... carcinoma and help to avoid unnecessary surgery in patients with benign tumors,” the authors say in research published online July 23 in The Lancet Diabetes & Endocrinology.
The triple-test strategy can be expected to make its way into international guidelines, notes joint lead author Irina Bancos, MD, an associate professor of endocrinology at the Mayo Clinic, Rochester, Minn., in a press statement issued by the University of Birmingham (England), which also had a number of researchers involved in the study.
“The findings of this study will feed into the next international guidelines on the management of adrenal tumors and the implementation of the new test will hopefully improve the overall outlook for patients diagnosed with adrenal tumors,” Dr. Bancos emphasized.
More imaging has led to detection of more adrenal tumors
Advances in CT and MRI imaging have increased the ability to detect adrenal incidentalomas, which are now picked up on about 5% of scans, and the widespread use of imaging has compounded the prevalence of such findings, particularly in older people.
Adrenocortical carcinomas represent only about 2%-12% of adrenal incidentalomas, but the prognosis is very poor, and early detection and surgery can improve outcomes, so findings of any adrenal tumor typically trigger additional multimodal imaging to rule out malignancy.
Evidence is lacking on the accuracy of imaging in determining whether such masses are truly cancerous, or benign, and such procedures add costs, as well as expose patients to radiation that may ultimately have no benefit. However, a previous proof-of-concept study from the same authors did show that the presence of excess adrenal steroid hormones in the urine is a key indicator of adrenal tumors, and other research has supported the findings.
All three tests together give best predictive value: EURINE-ACT
To further validate this work, the authors conducted the EURINE-ACT trial, a prospective 14-center study that is the first of its kind to evaluate the efficacy of a screening strategy for adrenocortical carcinoma that combines urine steroid profiling with tumor size and imaging characteristics.
The study of 2,017 participants with newly diagnosed adrenal masses, recruited from January 2011 to July 2016 from specialist centers in 11 different countries, assessed the diagnostic accuracy of three components: maximum tumor diameter (≥4 cm vs. <4 cm), imaging characteristics (positive vs. negative), and urine steroid metabolomics (low, medium, or high risk of adrenocortical carcinoma), separately and in combination.
Of the patients, 98 (4.9%) had adrenocortical carcinoma confirmed clinically, histopathologically, or biochemically.
Tumors with diameters of 4 cm or larger were identified in 488 patients (24.2%) and were observed in the vast majority of patients with adrenocortical carcinoma (96 of 98), for a positive predictive value (PPV) of 19.7%.
Likewise, the PPV for imaging characteristics was 19.7%. However, increasing the unenhanced CT tumor attenuation threshold to 20 Hounsfield units (HU) from the recommended 10 HU increased specificity for adrenocortical carcinoma (80.0% vs. 64.0%) while maintaining sensitivity (99.0% vs. 100.0%).
Comparatively, a urine steroid metabolomics result suggesting a high risk of adrenocortical carcinoma had a PPV of 34.6%.
A total of 106 patients (5.3%) met the criteria for all three measures, and the PPV for all three was 76.4%.
Using the criteria, 70 patients (3.5%) were classified as being at moderate risk of adrenocortical carcinoma and 1,841 (91.3%) at low risk, for a negative predictive value (NPV) of 99.7%.
“Use of radiation-free, noninvasive urine steroid metabolomics has a higher PPV than two standard imaging tests, and best performance was seen with the combination of all three tests,” the authors state.