Alev Selek1, Berrin Cetinarslan2, Zeynep Canturk2, Ilhan Tarkun2, Yusuf Hanazay3, Cigdem Vural4, Ihsan Anik5, Savaş Ceylan5. 1. Department of Endocrinology and Metabolism, Kocaeli University Faculty of Medicine, Umuttepe Kocaeli 41380, Turkey. Electronic address: alevselek@gmail.com. 2. Department of Endocrinology and Metabolism, Kocaeli University Faculty of Medicine, Umuttepe Kocaeli 41380, Turkey. 3. Department of Internal Medicine, Kocaeli University Faculty of Medicine, Umuttepe Kocaeli, Turkey. 4. Department of Pathology, Kocaeli University Faculty of Medicine, Umuttepe Kocaeli, Turkey. 5. Department of Neurosurgery, Kocaeli University Faculty of Medicine, Umuttepe Kocaeli, Turkey.
Abstract
PURPOSE: Somatostatin analogues (SSAs) can slow down the growth of neuroendocrine tumors. However, the mechanism remains unclear. Recent studies on patients with acromegaly suggest that SSAs may induce apoptosis, increase autophagy, and decrease cell proliferation of pituitary adenoma. Ki-67-labeling index is a marker of cellular proliferation; therefore, decreased levels are associated with inhibition of proliferation. The aim of this study was to evaluate and compare the Ki-67-labeling index of GH-secreting pituitary adenoma tissues in patients who had undergone pituitary surgery twice due to residual or recurrent tumors and had received SSA treatment between the two surgeries. METHOD: Thirty acromegaly patients who met the above criteria were identified and evaluated for the demographic, clinical and radiological features retrospectively. Surgical pathology samples of each operation were stained for Ki-67 and evaluated blindly by a staff pathologist specialized in pituitary diseases. RESULTS: Among patients who received SSA treatment between the first and second operations, the Ki-67 index of the adenoma at the second operation was significantly lower than the Ki-67 index at the first operation. There were no differences in clinical and radiological prognostic markers between the groups with decreased and unchanged Ki-67 index. CONCLUSION: We concluded that SSA treatment appears to decrease Ki-67 proliferation index independent of tumor features, SSA type, dose and treatment duration. This result suggests that SSA treatment may decrease cellular proliferation, supporting the previous studies.
PURPOSE: Somatostatin analogues (SSAs) can slow down the growth of neuroendocrine tumors. However, the mechanism remains unclear. Recent studies on patients with acromegaly suggest that SSAs may induce apoptosis, increase autophagy, and decrease cell proliferation of pituitary adenoma. Ki-67-labeling index is a marker of cellular proliferation; therefore, decreased levels are associated with inhibition of proliferation. The aim of this study was to evaluate and compare the Ki-67-labeling index of GH-secreting pituitary adenoma tissues in patients who had undergone pituitary surgery twice due to residual or recurrent tumors and had received SSA treatment between the two surgeries. METHOD: Thirty acromegalypatients who met the above criteria were identified and evaluated for the demographic, clinical and radiological features retrospectively. Surgical pathology samples of each operation were stained for Ki-67 and evaluated blindly by a staff pathologist specialized in pituitary diseases. RESULTS: Among patients who received SSA treatment between the first and second operations, the Ki-67 index of the adenoma at the second operation was significantly lower than the Ki-67 index at the first operation. There were no differences in clinical and radiological prognostic markers between the groups with decreased and unchanged Ki-67 index. CONCLUSION: We concluded that SSA treatment appears to decrease Ki-67 proliferation index independent of tumor features, SSA type, dose and treatment duration. This result suggests that SSA treatment may decrease cellular proliferation, supporting the previous studies.