Summary of clinical characteristics of common primary adrenal malignancies in adults

Abstract Background To summary the clinical characteristics of common primary adrenal malignancies in adults, the survival time of the patients, and the prognostic factors associated with these rare malignancies. Methods The Surveillance, Epidemiology, and End Results database (1975–2016) was queried for all patients who were diagnosed with primary adrenal malignancies, including adrenocortical carcinoma(ACC), pheochromocytoma and paraganglioma (PPGL), lymphoma, and sarcoma (SA). The clinical characteristics, overall survival (OS) and cancer-specific survival (CSS) were analyzed, in which propensity score methodology, logistic regression modeling and Kaplan-Meier survival curves were used. The Multivariate Cox proportional hazard model was used to identify factors affecting the prognosis of patients with ACC. Results 3204 patients with primary adrenal malignancies were identified, including 2180 with ACC, 593 with PPGL, 307 with lymphoma, and 124 with SA. Generally, PPGL had a better prognosis than others. For ACC and PPGL, the non-metastatic group had better OS and CSS than the metastatic group; for SA, the non-metastatic group had better OS, however, there was no significant difference in CSS between the two groups. Furthermore, For ACC, the single metastasis group had a better OS than the multiple metastasis group. After tumors metastasis, the surgery group, surgery of primary adrenal lesions, had better OS and CSS than the non-surgery group for ACC and PPGL. For lymphoma, the chemotherapy group had better OS and CSS; for ACC and PPGL, the chemotherapy group had better CSS and worse OS; for SA, the survival showed no significant difference between the two groups. Radiotherapy had the same effect on patients' survival as chemotherapy, except for the lymphoma and the ACC. As for lymphoma, the radiotherapy group had better CSS, whereas the survival showed no significant difference in OS between the two groups. For ACC, the non- radiotherapy group had better CSS and OS. More importantly, for lymphoma, under the condition that both cohorts were the same basically, the surgical group had a better prognosis. The prognosis of ACC was related to sex, age, seer historic stage, surgery, chemotherapy. Conclusion Understanding the clinical characteristics of these tumors and factors affecting prognosis can facilitate the selection of more appropriate clinical treatment options.