Supplementary Material for: Adrenocortical Carcinoma in Children: A Clinicopathological Analysis of 41 Patients at the Mayo Clinic from 1950 to 2017

Background/Aims: Adrenocortical carcinoma (ACC) is an aggressive childhood cancer. Limited evidence exists on a definite histopathological criterion to differentiate ACC from adrenocortical adenoma. The aim of this study was to investigate the clinicopathological data of children with ACC, identify prognostic factors, and validate a histopathological criterion to differentiate ACC from adrenocortical adenoma. Methods: This retrospective cohort included 41 children, followed at the Mayo Clinic from 1950 to 2017 (onset of symptoms ≤21 years). Outcomes of interest were: alive with no evidence of disease, alive with evidence of disease, and dead of disease. Results: Median age at onset of symptoms was 15.7 years (n = 41; range, 0.2–21 years). Female:male ratio was 3.6: 1. Mixed symptomatology (> 1 hormone abnormality) was the most common presentation (54%, n = 22). Sixty-six percent of patients (n = 27 out of 41) underwent total adrenalectomy. Metastatic disease was more common in children aged > 12 years (p = 0.002 compared to < 4 years). The most common sites of metastases were the liver and lungs. Overall 2-year and 5-year survival rates were 61% (95% CI 45–77) and 46% (95% CI 30–62), respectively. Metastasis at the time of diagnosis was independently associated with poor prognosis (risk ratio 13.7%; 95% CI 3.9–87.7). Weiss criteria (29%) and modified Weiss criteria (33%) were less accurate in younger patients (< 12 years), compared to the Wieneke index (100%). Conclusion: The presence of metastases was an independent prognostic factor. The Wieneke index was the most accurate in predicting clinical outcomes in younger children.