Primary site surgery for metastatic adrenocortical carcinoma improves survival outcomes: an analysis of a population-based database

Objective: To define the survival effect of surgery of primary adrenal malignant lesions in metastatic adrenocortical carcinoma (ACC) patients. Patients and methods: We used the Surveillance, Epidemiology and End Results (SEER) database (1973-2014) to identify metastatic ACC patients (stage IV by using European Network for the Study of Adrenal Tumors stage classification). Correlated variables, including age, sex, race, tumor laterality, treatment modality, lymph node dissection, surgery of metastatic site, tumor size, and tumor stage, were extracted. Univariate and multivariate Cox regression analyses were used to define the efficacy of surgery on survival outcomes, including overall survival and cancer-specific survival of ACC. Results: There were 290 metastatic ACC patients identified from the database. The overall median survival time was 7 (95% CI, 6-8) months. Among these patients, 118 patients received primary site surgery and 172 patients did not. In both univariate and multivariate analyses, primary site surgery significantly improved both overall (hazard ratio 0.413, 95% CI, 0.299-0.571, P < 0.01) and cancer-specific survival (hazard ratio 0.408, 95% CI, 0.290-0.574, P < 0.01) for metastatic ACC patients. Conclusion: Our study suggests that primary site surgery in metastatic ACC patients significantly improved overall and cancer-specific survival. Further multicenter prospective studies are still needed to validate these outcomes.