Cushing’s syndrome, also known as hypercortisolism, is an endocrine disorder that occurs due to abnormally high levels of the hormone cortisol production in the body. Cushing’s syndrome is broadly classified as endogenous and exogenous Cushing’s syndrome. Exogenous Cushing’s syndrome occurs due to excessive use of medications like glucocorticosteroids while endogenous cushing syndrome may be due to ACTH dependent causes or ACTH independent causes.
The incidence is around 1.2-1.7 per million per year for Cushing’s disease (CD), 0.6 per million per year for adrenal adenomas and 0.2 per million per year for adrenal carcinomas. All the other types of CS are very rare. Endogenous CS is more common in women. The most common types are ACTH-dependent CS (80-85%), of which CD constitutes 80% of cases and the ACTH-secreting pituitary adenomas and ectopic ACTH constitutes the rest 20% cases, whereas corticotropin-releasing hormone is diagnosed as a cause in around less than<1 cases.
Cushing syndrome is a rare disease with a prevalence of around 39 people per million. A total of 40,398 cases of Cushing’s Syndrome were diagnosed in 2015 and the total number of Cushing’s syndrome cases is expected to reach 41,683 in 2023 in the 7 major markets-United States, EU5 (France, Germany, Italy, Spain and United Kingdom) and Japan.
Treatment of Cushing’s syndrome depends on whether it is exogenous or endogenous, and the treatment can be broadly given as line of treatments. In first line of treatment, trans-sphenoidal surgery is considered in cases where Cushing’s syndrome onset was seen due to underlying tumor or pituitary stimulation- which causes ACTH production leading to Cushing’s syndrome. Glucocorticoid replacement and discontinuation is also considered as possible treatment options in case of exogenous Cushing’s syndrome. In second line of treatment, radiotherapy, adrenalectomy and drug therapies are considered. The medical therapy for Cushing’s syndrome includes drug therapies- which are broadly classified into Steroidogenesis inhibitors, Pituitary-directed drugs and combination therapies.