Efficacy of a Modified Fletcher Classification for Gastrointestinal Stromal Tumors

Introduction: The prognostic value of clinicopathological classification systems in gastrointestinal stromal tumors (GIST) has been evaluated. In our hospital, we have applied a modified Fletcher classification system to determine the high risk of recurrence and treated patients in the high-risk group by imatinib after surgery since 2012. We examined the feasibility of the modified Fletcher classification system. Methods: We analyzed 59 patients with primary GIST who underwent surgical resection in our hospital between January 2008 and December 2014. We analyzed the clinicopathological characteristics and the recurrence rate among groups according to the modified Fletcher classification and reported our outcomes of GIST. Results: There were 35 male and 24 female patients. The mean age was 66 years. Tumors were found in the stomach (42 patients), intestine (10 patients), duodenum (6 patients), esophagus (1 patients). About surgical procedure, we performed 22 open surgeries and 37 laparoscopic surgeries. People were assigned to 4 groups (very low, 10; low 18; moderate 5; high-risk 24) in accordance with the modified Fletcher classification respectively. Thirteen cases in 24 high-risk patients were treated by adjuvant imatinib therapy. The reasons for not giving postoperative imatinib were comorbidity and age in 2 cases, adverse effect in 1 case, and not recognizing as high-risk group because of cases before 2011 in 10 cases. Four patients, who were all in the high-risk group had recurrence, and the recurrence rate was significantly higher in the high-risk group than in other groups (16.7% vs. 0% P=0.023). There was also a significant difference for the 3-year recurrence-free survival rate between the high-risk group and other groups (79.2% vs. 100% P=0.009). Two patients of 16 patients with ulcer had recurrence(12.5%). Conclusion: All of 4 patients with recurrence were assigned to the high-risk group and there was a significant difference for the recurrence rate between the high-risk group and other groups. Patients with ulcer have a high tendency for recurrence and we should classify patients with ulcer as the high-risk group in the same manner as tumor lysis.