Significance of the Expression of Ki-67 and CyclinD1 Protein in Differentiating between Malignant and Benign Gastrointestinal Stromal Tumors

Objective To investigate the significance of the expression of the Ki-67 and cyclin D1 protein in differentiating between the malignant and benign gastrointestinal stromal tumors(GISTs).Methods The expression of Ki-67 and cyclin D1 protein was detected by immunohistochemistry in 41 cases of GISTs.Results The Ki-67 labeling index in the benign,the borderline and the malignant GISTs was(8.5±3.9)%?(16.8±8.6)% and(21.8±8.3)%,respectively,showing a significant difference between the three groups(P0.01).The Ki-67 labeling index was related to the tumor size,tumor necrosis and mitotic count.The positive rate of cyclin D1 protein in the benign,the borderline and the malignant GISTs was 16.7%,53.8% and 68.2% respectively.There was a significant difference in the cyclin D1 protein between the benign and the borderline GISTs,and between the benign and the malignant GISTs(P0.05),but not between the borderline and the malignant GISTs(P0.05).The positive rate of cyclin D1 protein was related to mitotic count,but not related to the tumor size and tumor necrosis.Conclusion The Ki-67 and cyclin D1 protein were valuable biomarkers in the differential diagnosis between the benign,the borderline and the malignant gastrointestinal stromal tumors.