Mitotane and Carney Complex: ten years follow-up of a low-dose mitotane regimen inducing a sustained correction of hypercortisolism.

OBJECTIVE: Primary pigmented nodular adrenocortical disease (PPNAD), an uncommon cause of Cushing's syndrome, is frequently associated with a wider clinical spectrum, the Carney complex (CC), a multiple endocrine neoplasia syndrome. DESIGN: We evaluated a low-dose mitotane regimen for treating severe hypercortisolism in a 27-year-old woman with CC. She presented with severe hypercortisolism and a history of surgeries for breast ductal adenoma, atrial cardiac myxomas with cerebral and peripheral arterial embolism, and near-total thyroidectomy because of an oxyphilic adenoma. The patient refused further surgery for adrenalectomy. RESULTS: During the first 7 months of mitotane (Lysodren, HRA Pharma, Paris, France), the daily oral dose was progressively increased from 0.5 to 4 g/day and then stopped because of the appearance of sustained signs of hypoadrenalism, that required a replacement therapy with 5 mg of prednisone o.d. A 10-month mitotane off-therapy follow-up was performed and when an increase in urine free cortisol (UFC) was noted, the mitotane regimen was restarted at lower doses (0.750-1 g/day). Serum morning cortisol levels and UFC were then maintained within the normal range, with plasma mitotane ranging between 2 and 4 mg/L. A sustained regression of Cushing's features without inducing hypoadrenalism was achieved, which still persists after 122 months of follow-up. Minimal initial gastric discomfort was the only side effect of which the patient complained and only during the first higher dose mitotane course. CONCLUSIONS: Long-term administration of a low maintenance dose of mitotane may be suggested as treatment for hypercortisolism in CC patients who refuse or are at high risk for surgical adrenalectomy.

Targeting epidermal growth factor receptor 1 signaling in human thyroid-stimulating hormone-independent thyroid carcinoma FRO cells results in a more chemosensitive and less angiogenic phenotype.

BACKGROUND: Poorly differentiated and anaplastic thyroid cancers are aggressive malignancies unresponsive to standard treatments. The mechanisms responsible for the progression of thyroid tumors toward a thyroid-stimulating hormone (TSH)-independent phenotype are still under discussion, and a better understanding of them may provide novel molecular targets for the treatment of this disease. We evaluated the hypothesis that epithelial growth factor (EGF) signaling may play a role in favoring the loss of TSH dependency in human differentiated thyroid tumor cells. METHODS: The sensitivity to EGF stimulation was evaluated in follicular thyroid carcinoma WRO cells that retain some features of thyroid cell differentiation and in undifferentiated TSH-independent thyroid carcinoma FRO cells. RESULTS: It was observed that, while both cell lines are characterized by a similar EGF-dependent activation of the RAS/MAPK signaling pathway, only FRO cells exhibited a significant induction of phosphoAKT, cell proliferation, and migration as well as the up-regulation of vascular endothelial growth factor-A expression in response to EGF. On the other hand, the inhibition of epidermal growth factor receptor 1 signaling by its tyrosine kinase inhibitor, erlotinib, caused a selective down-regulation of FRO cell proliferation and induced a phenotype more sensitive to the proapoptotic activity of anthracyclins and taxoids. By contrast, the protracted stimulation of TSH-dependent WRO cells with EGF induced the loss of TSH dependency and the rearrangement of F-actin cytoskeleton. CONCLUSIONS: These results suggest that the acquired sensitivity to EGF in these thyroid tumor cells may be responsible for the loss of differentiation in the transition toward a TSH-independent, invasive, and chemoresistant phenotype.