Long-term endocrine outcomes of transsphenoidal surgery for prolactinomas: a 20-year single-center cohort study.

BACKGROUND: The role of transsphenoidal surgery in the management of prolactinomas remains debated in the era of dopamine agonist therapy. This descriptive study evaluated the long-term endocrine outcomes of transsphenoidal surgery in a highly selected single-center surgical cohort. METHODS: We retrospectively reviewed all patients who underwent transsphenoidal surgery for prolactinomas at a tertiary referral center between September 1995 and July 2015. Biochemical remission was defined as normalization of serum prolactin levels 6 months after surgery. Persistent disease and recurrence were assessed during long-term follow-up. The analysis was descriptive and all subgroup comparisons were exploratory. RESULTS: Fifty-five patients were included (47 women and 8 men; median age, 30 years), comprising 35 microprolactinomas (64%), 18 macroprolactinomas (33%), and 2 giant prolactinomas (3%). The median follow-up was 10.8 years. Biochemical remission at 6 months was achieved in 29 patients (53%), whereas persistent disease and recurrence were observed in 21 (38%) and 5 patients (9%), respectively. Remission rates were 60% for microprolactinomas and 44% for macroprolactinomas, whereas both giant prolactinomas had persistent disease. No male patient achieved biochemical remission, whereas remission was observed in 29 of 47 women (62%). This observation is exploratory: 6 of the 8 men harboured a macro- or giant prolactinoma and their median preoperative prolactin level was 848.7 ng/mL, against 136.4 ng/mL in women. Transient diabetes insipidus occurred in 9% of patients, whereas permanent complications were uncommon. CONCLUSIONS: In this highly selected surgical cohort, transsphenoidal surgery was followed by durable endocrine control in approximately half of the patients and by a low recurrence rate. These descriptive findings are compatible with a role for surgery as a second-line option, but do not allow inference about its comparative effectiveness.