[Prognostic value of of the expression Ki-67, CD31, and VEGF in somatotropinomas]

Pituitary adenomas are benign, but 30-50% of patients do not achieve remission after treatment. The purpose of the study was to analyze the prognostic value of immunoexpression of the proliferation marker Ki-67 and the angiogenetic factors CD31 and VEGF in somatotropinomas. Ki-67, CD31, and VEGF were immunohistochemically studied in the samples of 52 somatotropin-removed samples; medical records were used to analyze the outcome of treatment in the early and late postoperative periods. Ki-67 immunoexpression proved to be significantly higher in the patients who had not achieve remission both in the early (p = 0.042) and late (p = 0.012) postoperative period than in those who had achieved remission and in patients who were resistant to postoperative treatment with somatostatin analogues (p = 0.040) than in those who were sensitive to therapy. The immunoexpression of CD31 and VEGF was not associated with the outcome of treatment. Thus, high Ki-67 levels may be regarded as a poor postoperative prognostic factor in acromegaly.