Multiplatform Integrative Analyses of Immunosuppressive Signatures in Cortisol-secreting Adrenocortical Carcinoma

Adrenocortical carcinoma (ACC) is a rare but highly aggressive malignancy and nearly half of ACC tumors have been shown to overproduce and secrete adrenal steroids. Excess cortisol secretion, in particular, has been associated with poor prognosis among ACC patients. Furthermore, recent immunotherapy clinical trials demonstrated significant immunoresistance among cortisol-secreting ACC (CS-ACC) patients when compared to their non-Cortisol-secreting (nonCS-ACC) counterparts. The immunosuppressive role of excess glucocorticoid therapies and secretion is well established, however, the impact of the cortisol hypersecretion on ACC tumor microenvironment (TME), immune expression profiles, and immune cell responses remain largely undefined. In this study, we characterized the TME of ACC patients and compared the immunogenomic profiles of nonCS-ACC and CS-ACC tumors to assess the impact of differentially expressed genes (DEGs) related to immune processes on patient prognosis. Comprehensive multiplatform immunogenomic computational analyses of ACC tumors deciphered an immunosuppressive expression profile with a direct impact on patient survival. We identified several primary immunogenomic prognostic indicators and potential targets within the tumor immune landscape of CS-ACC that define a distinct TME and provide additional insight into the understanding of potential contributory mechanisms underlying failure of initial immunotherapeutic trials and poor prognosis of patients with CS-ACC.