The Clinical Characterristics And Prognosis Of Extra-gastrointestinal Stromal Tumors:A Multicentre Retrospective Cohort Study In Shandong Province

Objective: To explore the clinicopathological characteristics,treatment and prognosis of extrogastrointestinal stromal tumor(EGIST)in Shandong Province.Methods: The E-GIST clinicopathological data were collected and reviewed from 23 University Teaching Hospitals in Shandong Province from Jan.2003 to Oct.2014.Patients also were followed up.Prognostic factors were evaluated by using Cox proportional hazard models and univariate and multivariate with Log-rank test.Results: 401 cases of EGIST including 177 males and 224 females were collected,The age was from 18 to 86 years(median 56 years).The follow-up periods were from 1 to141 months(median 35).304 of the 401 patients were living(120 cases with recurrence and metastasis),and 97 had died as tumor progression.The median survival time was 38 months.1,3 and 5-year overall survival rates were 90%,75% and 65% respectively.1,3and 5 years recurrence free survival rates were 88%,68% and 57% respectively.Patients underwent R0 resection had a better 5-year overall survival rate than those underwent R1resection(73%vs53%,P<0.05).The 5-year overall survival rate was 73% and 50%separately between taking and not taking imatinib in patients with intermediate risk of recurrence.The 5-year overall survival rate was 68% and 42% separately between taking and not taking imatinib in patients with high risk of recurrence.The 5-year overall survival rate was 68% and 62% between imatinib management and no-management in patients with intra-abdominal primary EGIST,the difference was not statistically significant(P> 0.05).Multivariate analysis revealed that age(P<0.05,RR=1.656,95%CI:1.055-2.600),tumor size(P<0.01,RR=2.180,95% CI:1.485-3.202),mitotic count(P<0.01,RR=1.797,95% CI:1.386-2.329)and tumor rupture(P<0.01,RR=2.112,95%CI:1.282-3.479)were independent prognostic factors.Conclusion:Age,tumor size,mitotic count and tumor rupture affect the prognosis of patients after resection of primary EGISTs independently.Adjuvant imatinib can effectively improve the prognosis of the patients with high risk of recurrence,and the survival rate of patients after surgery.Surgical resection is the main treatment of EGIST,and R0 resection helps to prolong the survival time.The postoperative survival rate is low for multiple primary EGIST especially.