Novel methods of treating tumors, including neuroendocrine tumors (NET), such as a catecholamine-secreting tumor (CST), are disclosed. The methods include treating Cushing's syndrome in a Cushing's syndrome patient having a NET, such as a CST. Tumors may be treated with a glucocorticoid receptor (GR) modulator (GRM), such as a GR antagonist (GRA). The novel treatments may treat Cushing's syndrome, may reduce catecholamine production by the tumor, may reduce catecholamine excess, may ameliorate symptoms of catecholamine excess, and may improve the efficacy of α-adrenergic or β-adrenergic blockade, somatostatin or somatostatin analog treatment or imaging, or Peptide Receptor Radionuclide Therapy, in patients with a CST. The GRM may reduce the activation of a GR, and may bind to a GR with higher affinity than it binds to a progesterone receptor (PR). In embodiments, the drug may only poorly bind to PR, or may not measurably bind to PR.
