Complete clinical and biochemical control with cabergoline and octreotide in a patient with ectopic ACTH syndrome before surgery

The dopaminergic control of Cushing's syndrome

Cushing's Syndrome (CS), or chronic endogenous hypercortisolism, is a rare and serious disease due to corticotroph pituitary (Cushing's disease, CD) and extra-pituitary (ectopic CS) tumours overproducing ACTH, or cortisol-secreting adrenal tumours or lesions (adrenal CS). The first-line treatment for CS is represented by the surgical removal of the responsible tumour, but surgery might be unfeasible or ineffective and medical treatment can be required in a relevant percentage of patients with CS, especially CD and ectopic CS. Corticotroph pituitary and extra-pituitary tumours, as well as adrenal tumours and lesions responsible for CS express dopamine receptors (DRs), which have been found to mediate inhibition of hormone secretion and/or cell proliferation in experimental setting, suggesting that dopaminergic system, particularly DRs, might represent a target for the treatment of CS. Dopamine agonists (DAs), particularly cabergoline (CAB), are currently used as off-label treatment for CD, the most common form of CS, demonstrating efficacy in controlling hormone secretion and tumour growth in a relevant number of cases, with the improvement of clinical picture, and displaying good safety profile. Therefore, CAB may be considered a reasonable alternative treatment for persistent or recurrent CD after pituitary surgery failure, but occasionally also before pituitary surgery, as adjuvant treatment, or even instead of pituitary surgery as first-line treatment in case of surgery contraindications or refusal. A certain beneficial effect of CAB has been also reported in ectopic CS. However, the role of DAs in the clinical management of the different types of CS requires further evaluations.

Cabergoline in severe ectopic or occult Cushing's syndrome

CONTEXT

Cabergoline has been shown to have some effect in the treatment of moderate Cushing's disease, but its effectiveness in Cushing's syndrome of ectopic or occult origin remains to be investigated.

CASE SERIES

In this case series, cabergoline was used in combination with steroidogenesis inhibitors in nine patients with severe Cushing's syndrome of ectopic or occult origin. Cabergoline's effectiveness enabled rapid withdrawal of the steroidogenesis inhibitors and long-term control of the hypercortisolism in three of the cases.

REVIEW OF THE LITERATURE

In the literature, we found only 11 cases of ectopic or occult Cushing's syndrome treated with dopamine receptor agonists, alone or in combination. Yet of these 11 cases, 10 responded.

CONCLUSIONS

Although limited, the existing experience highlights the potential value of cabergoline in the treatment of ectopic or occult Cushing's syndrome.