Discussion On The Risk Factors Of Postoperative Recurrence And Metastasis Of Gastrointestinal Stromal Tumors With Very Low-risk And Low-risk

Objective: According to the 2008 modified NIH recurrence risk grading system,patients with very low-risk and low-risk GISTs had a low risk of recurrence and did not require postoperative adjuvant targeted therapy.However,there are still a few patients with recurrence and metastasis after surgery.Therefore,this study explored the clinicopathological factors of postoperative recurrence and metastasis in patients with very low-risk and low-risk GISTs,in order to individualize patients with very low-risk and low-risk GISTs with high recurrence potential.Postoperative adjuvant targeted therapy improves patient outcomes.Materials and Methods: 606 patients with GISTs who underwent R0 resection in our hospital from April 2011 to December 2015 were selected,and 170 patients with very low-risk and low-risk GISTs were screened out(all were not treated with imatinib).The clinical and pathological data of the patients in this group were statistically analyzed to find out the clinicopathological factors of postoperative recurrence and metastasis in patients with very low-risk and low-risk GISTs.Result: 1)A total of 170 patients were collected,of which 46(27.1%)were very low-risk patients and 124(72.9%)were low-risk patients.Recurrence and metastasis occurred in 13(7.6%)of the 170 patients.2)In the correlation analysis,the poor prognosis of patients with very low-risk and low-risk GISTs was significantly correlated with age,primary site,diameter,mitotic pattern,growth pattern,MDM-2,p53 and Ki-67(P< 0.05),but no significant correlation with other clinicopathological features(P>0.05).3)The median diameter of the tumor was 3.0 cm(0.2 cm-5.0 cm).According to the correlation analysis,it was found that the diameter was significantly correlated with the poor prognosis of the patient.Therefore,the optimal cutoff value of the diameter was calculated using the ROC curve to be 3.9 cm.4)Kaplan-Meier survival curves show recurrence-free survival in patients of very low-risk,low-risk GISTs at different ages,primary sites,diameters,growth patterns,mitotic figures,Ki-67,and MDM-2 There were significant differences in survival,RFS),and the difference was statistically significant(P<0.05).5)Univariate analysis and multivariate analysis showed that tumor diameter,MDM-2,and Ki-67 were independent risk factors for postoperative recurrence-free survival in patients with very low-risk and low-risk GISTs.Conclusion: Tumor diameter >3.9cm,Ki-67 and MDM-2 protein overexpression are independent risk factors for postoperative RFS in patients with very low-risk and low-risk GISTs.These three should be combined with the 2008 modified NIH recurrence risk grading system.Factors to determine the prognosis of patients with very low-risk,low-risk GISTs and whether they receive targeted therapy after surgery.