Clinical and laboratory characteristics and results of treatment of patients with ACTH-producing neuroendocrine tumors of various localization

Aim. To study the clinical, biochemical characteristics, treatment results and follow-up of patients with ectopic ACTH syndrome – EAS (ACTH – adrenocorticotropic hormone ). Materials and methods. A retrospective, observational, single-center study of 130 patients with EAS. Demographic information of patients, medical history, results of laboratory and instrumental investigations at the pre- and postoperative stages and follow-up of EAS were analyzed. Results. The mean age at the diagnosis ranged from 12 to 74 years ( Me 40 years [28; 54]). The duration of the disease from the onset of symptoms to the verification of the diagnosis varied from 2 to 168 months ( Me 17.5 months [7; 46]). Eighty-one (62,3%) patients had bronchopulmonary NET, 9 – thymic carcinoid, 7 – pancreatic NET, 5 – pheochromocytoma, 1– cecum NET, 1– appendix carcinoid tumor, 1 – medullary thyroid cancer and 25 (19.2%) had an occult source of ACTH. The median follow-up period of patients was 27 months [9.75; 61.0] with a maximum follow-up of 372 months. Currently, primary tumor was removed in 82 (63.1%) patients, bilateral adrenalectomy was performed in 23 (18%) patients, in 16 of them there was an occult source of ACTH-producing NET and in 7 patients – in order to control hypercortisolism after non-successful surgical treatment. Regional and distant metastases were revealed in 25 (19.2%) patients. At the time of the last observation 59 (72%) patients were exhibited a full recovery, 12 (14.6%) – had relapse of the disease and 26 (20%) – died from multiple organ failure ( n= 18), pulmonary embolism ( n= 4), surgical complications ( n= 2), disseminated intravascular coagulation syndrome ( n= 1) or COVID-19 ( n= 1). Conclusion. In our cohort of patients bronchopulmonary NET are the most frequent cause of EAS (62.3%). Surgical treatment leads to remission of hypercortisolism in 72% cases; the proportion of relapse (14.6%) and fatal outcome (20%) remains frequent in EAS.