Predictive factors for recurrence of Cushing's disease after pituitary surgery.

Introduction: The first-line treatment for Cushing's disease (CD) is transsphenoidal excision of the corticotropic adenoma.

Aim: To identify the predictive factors of recurrence of corticotropic adenomas after pituitary surgery.

Methods: This is a retrospective and longitudinal study conducted in 28 patients operated for corticotropic adenoma between 1987 and 2014 and followed up in the department of endocrinology of La Rabta Hospital in Tunis (Tunisia). The mean duration of follow-up was 82 ± 65.9 months. The population was subdivided into two groups according to the occurrence or not of a recurrence. Recurrence was defined by hormonally confirmed postoperative recurrence of Cushing's syndrome.

Results: The mean age of the patients was 30.8±11.8 years (24 women and 4 men). CD was related to a microadenoma in 46% of cases (n=13) and a macroadenoma in 54% of cases (n=15). The recurrence rate was 28% (n=8/28). The mean time to diagnosis of recurrence was 5.6±4 years. The sex ratio (F/M) was 7 in the recurrence group (R) and 5.6 in the non-recurrence group (NR); p= NS. The mean age of patients in the (R) group was 27.2±11.8 years and 32.2±11.9 years in the (NR) group; p= NS. The recurrence rate was 63% in case of macroadenoma and 37% in case of microadenoma; p= NS. Postoperative cortisolemia was significantly higher in the recurrence group (23.2 ± 13.5 µg/dl vs 4.4 ± 3.9 µg/dl; p 4.4 µg/dl was significantly associated with recurrence (100% vs 26.3%; p= 0.001). The duration of corticotropic axis inertia was 67.2 ± 47.7 months in the (R) group versus 88.37 ± 72.14 months in the (NR) group; p= NS.

Conclusions: Nearly a quarter of patients operated for CD develop a recurrence within five years. A postoperative cortisol level > 4.4 µg/dl is predictive of disease recurrence. Multicenter studies and a larger sample are needed to support these results.