目的:分析小肠原发胃肠间质瘤(GIST)患者的临床病理特征、基因突变特点和预后的相关因素。方法:回顾性收集2011年1月1日至2019年12月30日在天津医科大学肿瘤医院未行术前辅助治疗、经手术切除和病理确诊的小肠原发GIST，使用聚合酶链反应和Sanger直接测序法检测n KIT基因外显子9、11、13、17，以及血小板源性生长因子受体α(n PDGFRA)基因外显子12、18的突变情况，分析临床病理和基因突变特征。采用Pearson卡方检验和Bonferroni连续校正检验进行分类变量的组间比较。采用Kaplan-Meier法和log-rank检验进行单因素生存分析，Cox比例风险回归模型进行多因素生存分析。n 结果:空肠和回肠GIST肿瘤最大径>10.0 cm和高危GIST的患者占比均高于十二指肠GIST[18.7%(28/150)比6.4%(5/78)、56.7%(85/150)比43.6%(34/78)]，差异均有统计学意义(n χ2＝14.67、12.46，n P＝0.002、0.006)。在进行基因检测的58例小肠原发GIST患者中，n KIT基因突变型和野生型分别占84.5%(49/58)和15.5%(9/58)，其中34例(69.4%)、12例(24.5%)、2例(4.1%)和1例(2.0%)分别为n KIT基因外显子11、9、13、17突变，未发现n PDGFRA基因突变的病例。小肠原发GIST患者的3、5和10年无进展生存率分别为88.1%、85.0%和68.3%，3、5和10年总生存率分别为96.6%、94.5%和86.1%。单因素生存分析结果显示，极低危、低危小肠原发GIST患者的无进展生率和总生存率均高于中危、高危患者[分别为100.0%(49/49)比72.3%(81/112)、100.0%(49/49)比89.3%(100/112)]，差异均有统计学意义(n χ2＝14.07、4.92，n P5个/5 mmn 2、Ki-67增殖指数>5%和未接受术后辅助治疗均与患者的无进展生存期有关，差异均有统计学意义(n χ2＝8.39、5.53、13.73、15.44，n P＝0.004、0.019、10%均与患者的无进展生存期有关，差异均有统计学意义(n χ2＝10.08、6.51、10.37、15.72，n P＝0.001、0.011、0.001、5%[n HR＝5.018，95%置信区间(95%n CI)1.745~14.430，n P＝0.003)]和未接受术后辅助治疗(n HR＝0.145，95%n CI 0.051~0.414，n P10%(n HR＝8.381，95%n CI 1.364~51.487，n P＝0.022)是未接受术后辅助治疗的中危、高危小肠原发GIST患者术后肿瘤进展的独立危险因素。n 结论:小肠原发GIST中最常见的突变类型为n KIT基因突变型，其次为野生型，未发现n PDGFRA基因突变的病例。高Ki-67增殖指数可提示中危、高危小肠原发GIST患者预后不良，术后辅助治疗可显著改善中危、高危小肠原发GIST患者的预后。n “,”Objective:To analyze the clinicopathological features, gene mutation characteristics, and prognostic related factors of patients with primary gastrointestinal stromal tumor (GIST) of small intestine.Methods:From January 1, 2011 to December 30, 2019, surgical resected and pathological diagnosed small intestinal GIST without preoperative adjuvant therapy, at Tianjin Medical University Cancer Institute & Hospital were retrospectively collected. The mutational status of n KIT exons 9, 11, 13, and 17 and platelet-derived growth factor receptor alpha (n PDGFRA) exons 12 and 18 were detected by polymerase chain reaction and Sanger direct sequencing. Clinicopathological features and gene mutation characteristics were analyzed. Pearson chi-square test and Bonferroni continuous correction test were used to compare the categorical variables among groups. Kaplan-Meier method and log-rank test were used for univariate survival analysis. The multivariate Cox proportional hazards regression model was used for multivariate survival analysis.n Results:The proportions of patients with maximum tumor diameter> 10.0 cm and high-risk GIST located in the jejunum and ileum were higher than those of patients with primary GIST located in the duodenum (18.7%, 28/150 vs. 6.4%, 5/78; 56.7%, 85/150 vs. 43.6%, 34/78), and the differences were statistically significant (n χ2=14.67 and 12.46, n P=0.002 and 0.006). The results of gene detection of 58 cases of small intestinal GIST indicated that the percentage of n KIT gene mutant and wild type accounted for 84.5% (49/58) and 15.5% (9/58), among which 34 cases (69.4%), 12 cases (24.5%), 2 cases (4.1%) and 1 case (2.0%) were n KIT gene exons 11, 9, 13 and 17 mutations, respectively, and none of the case with n PDGFRA mutation. The 3-, 5-, and 10-year progression-free survival rates of the patients with small intestinal GIST were 88.1%, 85.0%, and 68.3%, respectively, and the 3-, 5-, and 10-year overall survival rates were 96.6%, 94.5%, and 86.1%, respectively. The results of univariate survival analysis showed that the progression-free survival rate and overall survival rate of patients with very low-risk and low-risk GIST were higher than those of patients with intermediate-risk and high-risk GIST (100.0%, 49/49 vs. 72.3%, 81/112; 100.0%, 49/49 vs. 89.3%, 100/112, respectively), and the differences were statistically significant (n χ2=14.07 and 4.92, n P5/5 mmn 2, Ki-67 proliferation index >5%, and without postoperative adjuvant therapy were all related with progression-free survival time, and the differences were statistically significant ( n χ2=8.39, 5.53, 13.73 and 15.44, n P=0.004、0.019、10% were all related with progression-free survival time, and the differences were statistically significant ( n χ2=10.08, 6.51, 10.37 and 15.72, n P=0.001、0.011、0.001、5% (n HR=5.018, 95% confidence interval(95%n CI) 1.745 to 14.430, n P=0.003) and without postoperative adjuvant treatment (n HR=0.145, 95%n CI 0.051 to 0.414, n P10% (n HR=8.381, 95%n CI 1.364 to 51.487, n P=0.022) was an independent risk factor of postoperative tumor progression in patients with small intestinal intermediate-risk and high-risk GIST and without postoperative adjuvant treatment.n Conclusions:The most common mutation in small intestinal primary GIST is n KIT mutation, followed by wild type, no case of n PDGFRA gene mutation has been found. High Ki-67 proliferation index can predict poor prognosis of patients with moderate-risk and high-risk small intestinal primary GIST. Postoperative adjuvant therapy can significantly improve the prognosis of patients with small intestinal intermediate-risk and high-risk primary GIST.n