The Expression And Clinical Significance Of CD117, Nestin And Ki-67 In Gastrointestinal Stromal Tumors

Objective: By detecting the expression of CD117, nestin and Ki-67 in gastrointestinal stromal tumors(GISTs)and analyzing the correlation between the clinical characteristics, biological behavior, pathological characteristics and these indexes, we get a preliminary discussion on the expression and clinical significance of these indexes ingastrointestinal stromal tumors.Methods: The study conducts 68 patients with gastrointestinal stromal tumors at NO.2 People’s Hospital of Changshu from June 2005 to June 2015, which have complete data and definite diagnosis. At the same time, 10 cases of leiomyoma of gastrointestinal tract and 10 normal gastrointestinal tissues are collected as control groups. The expression of Ki-67, nestin and CD117 in gastrointestinal stromal tumors is detected by immunehistochemistry staining. After staining, We choose 10 high-magnification randomly, counting the positive cells in 1000 tumor cells, then taking their average. the CD117 and nestin are scord as negative(-), positive(+) and strong positive(++).(-)respresents a positive cell number ≤ 5% of tumor cells counting,(+) respresents a positive cell number between 5% and 50%(including 50%) of tumor cells counting,(++)respresents a positive cell number >50% of tumor cells counting. Ki-67 staining results are graded according to the proliferation index and divided into three grades, < 1%,1%-5%(including 1% and 5%), >5%.Result: For the immunohistochemical staining with CD117, 3(4.4%) of the 68 cases are negative. 65(95.6%) are positive, and 19 are classified as(+), and 46 as(++). For nestin, 4 patients(5.9%) are negative. 64 cases(94.1%) are positive and in which 9 are classified as(+), 55 as(+ +). No significant correlations are found between CD117 positive rate and gender, age, localization, grade, cellular type, growth pattern,histological features, or invasion depth(p > 0.05). Neither are nestin(p > 0.05). Thepositive lever of nestin and CD117 are not significantly correlated with the risk grade. In10 cases of leiomyoma of gastrointestinal tract and 10 normal gastrointestinal tissues, all of them are negative staining for nestin and CD117.When we staine the samples for Ki-67, 31 cases(38.3%) are below 1%, 20(25%)are between 1% to 5%, 17(22.1%) are above 5%. There is significant difference between the Ki-67 proliferation index rates and the risk grades(p < 0.05). The higher the risk grade of the tumor, the higher the proliferation index rate. In addition, the Ki-67 proliferation index rates are also correlate with necrosis, hemorrhage and invasion depth(p<0.05): The Ki-67 proliferation index rate is more likely to below 1%, if there is no necrosis or hemorrhage in the tumor, or the tumor invade the submuscosal and muscle layer. There are no significant differences between other factors(gender, age, localization,grade, cellular type, growth pattern, bleeding in tumor) and the Ki-67 proliferation index rates(p>0.05). In 10 cases of normal tissues, The Ki-67 proliferation index rates are all below 1%. In 10 cases of leiomyoma, 8 cases are below 1%, 2 are in 1% to 5%, there is no significant difference between the proliferation index rate of Ki-67 in GISTs and in leiomyoma of gastrointestinal tract, p>0.05(p=0.123).Conclusion: 1.The expression of nestin, the same as CD117, is one of the important characteristics of GISTs, it can be used as a new index for the diagnosis of GISTs. 2. The study of this group can not prove that the expression of nestin in CD117-negative-GISTs cases is higher than that in CD117-Positive-GISTs cases. However, combined using of CD117 and nestin is benefit for improving the accuracy of diagnosis of gastrointestinal stromal tumors. 3. No significant correlations are found between CD117 Positive rate and gender, age, localization, grade, cellular type, growth pattern, histological features, or invasion depth. Neither are nestin. They can’t get further evaluation for tumors. 4. The Ki-67 proliferation index rate is significantly related to the risk grade of tumor. The higher the risk grade of the tumor, the higher the proliferation index rate.