The Relationship Between The Characteristics Of C-kit Gene Mutation And The Prognosis Of Patients With Gastrointestinal Stromal Tumors After R0 Resection

Objective: To investigate the relationship between the type of C-kit proto-oncogene mutation（C-kit）and the prognosis of patients with R0 resection of GIST and the risk factors of postoperative recurrence.Methods: A total of 66 cases of gastrointestinal stromal tumors obtained from surgery and pathologically confirmed at the Lu’an people’s hospital from January 2013 to June2018 were selected.The complete demographic data and all baseline clinical data were collected.The hot spots of C-kit gene mutation were concluded by gene detection.The 3-year disease-free survival rate（DFS）was observed by follow-up.Univariate analysis was used to analyze the related factors affecting 3-year DFS after operation,and multivariate Cox regression model analysis was used to analyze the related factors in univariate analysis.3-year DFS with different types of C-kit gene mutation was used to construct survival curve.Results: The results of gene detection showed that C-kit mutations in patients with GIST mainly occurred in exon 11（50/66,75.76%）,followed by exon 9（8/66,12.12%）.The results of univariate analysis showed that the maximum tumor diameter,mitotic image count,tumor rupture,Ki-67 increment index,NIH grade,TNM stage and C-kit mutation type were significantly correlated with 3-year DFS after operation.The results of single factor analysis were incorporated into the multi-factor Cox regression model.The results showed that the maximum diameter of tumor≥5（RR=1.839,95%CI 1.122～3.013）,mitotic image count≥5（RR=6.580,95%CI 1.382～31.317）,tumor rupture（RR=2.275,95%CI 1.251～4.136）,Ki-67 increment index≥5（RR=3.418,95%CI 1.073～10.885）,medium and high risk NIH grade（RR=4.693,95%CI 1.551～14.202）,TNM stage II,stage III（RR=8.306,95%CI 1.248～55.275）,C-kit gene exon 9 and 11（RR=4.208,95%CI1.682～10.531）and the independent risk factors of recurrence within 3 years after operation（P<0.05）.The 3-years DFS curves of exon 9、11、13、17 were 37.50%、51.22%、80.00%、100%.Conclusions: The mutations of C-kit in gastrointestinal stromal tumor disease have a significant correlation with prognosis,which may play an important role in the progression of gastrointestinal stromal tumor disease.Exon 9 and Exon 11 mutations are independent risk factors for recurrence within 3 years.The different types of C-kit mutation can be used to evaluate the prognosis of patients with GIST and to make individualized treatment for the prevention and treatment of postoperative recurrence and metastasis.