Endocrine Abstracts

Transsphenoidal surgery is the treatment of choice in acromegaly. However, some patients do not achieve postoperative remission. The aim of our study was to identify factors that predictive of a poor surgical outcome in patients with acromegaly. In our study we included 39 acromegalic patients, who underwent transsphenoidal surgery as initial treatment. We evaluated clinical, hormonal and radiological predictors based on magnetic resonance imaging (MRI). Also we examined immunohistochemical features of removed pituitary adenomas. Spearman’s correlation coefficients showed that young age (P=0.04), visual disturbances (P=0.03), symptoms of hyperprolactinemia (P=0.034), high preoperative basal growth hormone (GH) level (P=0.00005), and intracavernous adenoma extension (P=0.048) were significantly correlated with a poor surgical outcome. We used immunohistochemical staining of removed adenomas for proliferation marker (ki67), angiogenesis index (CD31), marker for malignancy potential (galectin-3), and pituitary hormone prolactin to assess the biological tumor behavior. Ki67 was present in 23% adenomas, CD31 — in 41%, galectin-3 — in 28%, prolactin — in 23%. Preoperative basal GH level was shown to be significantly higher (under Mann-Whitney’s test) in patients with positive immunostaining for galectin-3 (P=0.026) and for CD31 (P=0.022) than in patients with negative one. Though we did not find significant correlation between remission rate and these markers. Positive immunostaining for ki67 and prolactin was significantly correlated with MRI-predictors of unsuccessful surgical outcome (large size and intracavernous extension of adenomas). In addition, there were no cases of remission in patients with positive immunostaining for ki67 and prolactin. Summarizing above, evaluation of immunohistochemical predictors of removed adenomas we listed before (ki67, CD31, galectin-3, prolactin) in acromegalic patients gives the information which can determine (in combination with other predictive factors) surgical outcome and postoperative adjunctive therapy for such patients.