Endocrine Abstracts

The study analyses direct postoperative and long-term results of surgical treatment of ACTH-secreting pituitary adenomas in 158 patients, operated between 2004 and 2009. There were 143 (91%) female and 15 (9%) male. The mean age of the patients was 36 years, S.D. 10.7. In all patients the diagnosis of Cushing’s disease was confirmed by high dose dexamethasone suppression test. Preoperative hormonal evaluation: ACTH (0800 h), pg/ml (Me-78.5 (50.5 (25th percentile)–115.6 (75th percentile)), ACTH (11 pm), pg/ml (Me-69.9 (43.2–109)), cortisol (0800 h), nmol/l (Me-707.5 (553–884)), cortisol (2300 h), nmol/l (Me-584.5 (425–725)), urinary free cortisol (UFC), nmol/l (Me-1352 (936.7–2387.5)).

In the early postoperative period morning serum cortisol level <140 nmol/l was achieved in 69%; normalization of morning and midnight serum cortisol and UFC – in 86%. In 6 months postoperative normalization of UFC level was 79%, in 12 months – 81.3%, in 24 months – 71%. Normalization of UFC level and morning serum cortisol level during low-dose dexamethasone test <50 nmol/l was reached in 72.2, 50 and 55.6% after 6, 12 and 24 months after surgery respectively.

Morning serum cortisol level in the early postoperative period correlated with serum cortisol level in 6 (P=0.00014) and 12 (P=0.0071) months after operation, and also with UFC level in 6 (P=0.000007), 12 (P=0.0017) and 24 (P=0.017) months after operation. Such factors as longer duration of the disease (P=0.04), tumor invasiveness, (P=0.0087), lower decrease rate of serum cortisol level immediately after surgery (P=0.000025, 0.002 and 0.005 for 6, 12 and 24 months after surgery respectively) and lower decrease rate of ACTH level immediately after surgery (P=0.006, 0.0003 and 0.00035 for 6, 12 and 24 months after surgery respectively) were shown to be predictors for unfavourable postsurgical prognosis. Age, adenoma size and detection of mitosis on pathology in our study did not influence surgical outcome.