Androgen secretion in ectopic ACTH syndrome and in Cushing's disease: Modifications before and after surgery

The role of ACTH in the control of adrenal androgen secretion is known, alt hough the possible existence of other regulatory factors has been also sugg ested. While some data concerning Cushing's disease have been reported, onl y few studies concerned androgen levels in ectopic ACTH secretion. The aim of this study was to evaluate serum DHEA-S, androstenedione (A) and testost erone (T) levels in 36 women with ACTH-dependent Cushing's syndrome (30 wit h Cushing's disease and 6 with ectopic ACTH secretion) before and after sur gery. Two men with ectopic ACTH production were also studied. In 30 women w ith Cushing's disease serum DHEA-S (9.6 +/- 0.9 mu mol/l), A (15.2 +/- 1.2 nmol/l) and T (4.1 +/- 0.5 nmol/l) were higher than in controls (p < 0.01): elevated DHEA-S, A and T values were found in 8, 18 and 17 cases, respecti vely. After adenomectomy in 15 apparently cured patients DHEA-S, A and T le vels were low at 1-3 months and at 6-12 months after surgery. At 18-24 mont hs, DHEA-S remained low in spite of cortisol normalisation. In ectopic Cush ing's syndrome, A levels were significantly higher (23.1 +/- 4.9 nmol/l) th an in Cushing's disease (p < 0.05), while no differences were found in DHEA -S and T levels. Two patients had elevated DHEA-S values, 3 women had high T levels and 7 of the 8 patients had very high A concentration that was low ered in 3 operated cases. In conclusion, the pattern of adrenal androgen se cretion is rather different in patients with pituitary or with ectopic Cush ing's syndrome. While the frequency of DHEA-S and T alterations is similar, androstenedione secretion is greatly increased in the latter condition. It is suggested that in ACTH-secreting non-pituitary tumours, the production of a POMC-derived peptide, although unidentified, may lead to preferentiall y stimulated androstenedione secretion, without affecting other enzymatic p athways.