Prognostic analysis of primary extra-gastrointestinal stromal tumors

Objective: To analyze factors related to the prognosis of primary extra-gastrointestinal stromal tumors (EGISTs). Methods: The pathological and clinical data of 42 patients with primary EGISTs was collected and retrospectively analyzed. The patients were hospitalized from January 2004 to December 2013 and received complete surgical resection in Ruijin Hospital. The follow-up of postoperative patients was performed to obtain information about recurrence. The influence of clinical and pathological factors on the disease-free survival (DFS) of patients was analyzed. Results: Postoperative tumor recurrence was found in 24 patients during follow-up; 8 patients died of tumor recurrence and 1 patient died of other reasons. Kaplan-Meier univariate survival analysis revealed that tumor size, tumor mitotic count, and Ki-67 index were correlated with the DFS of patients (P=0.024, 0.001, 0.039, respectively). Cox multivariate regression analysis confirmed that tumor mitotic count was an independent prognostic factor affecting DFS post tumor surgery. Conclusions: Tumor size, tumor mitotic count, and Ki-67 index were correlated with EGIST recurrence. Tumor mitotic count was an independent prognostic factor influencing tumor recurrence.