Survival Predictors of Metastatic Adrenocortical Carcinoma: a SEER-based Retrospective Study

Abstract Background: Metastatic adrenocortical carcinomas (MAC) have a poor prognosis. Advanced adrenocortical carcinoma often metastasizes to lung and liver. Prognostic factors of MAC have been rarely reported. This study aims to identify the association between specific metastasis and overall survival (OS) in MAC and determine the survival predictors for MAC patients.Methods: MAC patients' data was obtained from Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2016. Survival differences were analyzed by Kaplan–Meier analysis and log-rank tests. Cox proportional hazard model was used to identify the prognostic factors associated with overall survival.Results: A total of 152 MAC patients were selected, among whom 77 patients (50.7%) were diagnosed with one metastatic site, 75 (49.3%) diagnosed with more than one distant metastasis. For the whole MAC cohort, multivariable analysis showed that year of diagnosis between 2013 and 2016, without liver metastasis, surgery and chemotherapy were significantly favorable predictors of OS. For patients with one metastatic site, lung metastases had a better survival outcome than liver metastases(p=0.037). Besides, compared with patients who didn’t received surgery, patients underwent surgery were correlated with longer OS (p=0.004). For patients with more than one site of distant metastases, married status, surgery, and chemotherapy predicted a better OS. Radiotherapy did not improve overall survival outcomes in the three cohort.Conclusion: Liver metastasis has a poor prognosis. Year of diagnosis, metastatic sites, surgery and chemotherapy were significant prognostic factors for OS in MAC patients. For patients with single metastasis, surgery was a favorable prognostic factor, while married patients, surgery and chemotherapy predicted a better survival outcome in patients with more than one metastasis. Based on the collective findings, surgery can be regarded as the preferred treatment option for all MAC patients. Besides, chemotherapy is also a good choice for patients with multiple metastases.