Cavernous sinus invasion and effect of immunohistochemical features over remission in growth hormone secreting pituitary adenomas

Abstract

We examined the cavernous sinus invasion and tumor biological markers that influence the remission rate. Cavernous sinus (CS) invasion was evaluated radiologically. Tumor biological markers consisting of the tumor cell growth parameter Ki-67 and the cancer cell vasculature marker of vascular endothelial growth factor (VEGF) were evaluated. We examined 28 immunohistochemically proven GH secreting pituitary adenoma patients who had been operated via endoscopic transsphenoidal surgery at Department of Neurosurgery, Kocaeli University Hospital between 2003 and 2008. Pathology preparations were stained with Ki-67 and VEGF. We evaluated remission at the postoperative 6th week. The basal GH level, nadir GH level and IGF-1 levels were evaluated to determine remission. Remission was achieved in 6 of 18 patients (33%) who had cavernous sinus invasion. Remission was achieved in 7 of 10 patients (70%) who did not have cavernous sinus invasion. There was no correlation between the Ki-67 proliferation index and cavernous sinus invasion (p=0.593). There was a positive correlation between VEGF expression and cavernous sinus invasion (p=0.03). The remission rate found less in the cavernous sinus invasion group. No association was found between Ki 67 proliferation index and cavernous sinus invasion. We found that a positive correlation between VEGF expression and cavernous sinus invasion. VEGF expression can therefore indirectly affect remission via cavernous sinus invasion.