OBJECTIVETo study the clinicopathologic features and prognostic factors of gastrointestinal stromal tumor (GIST).

METHODSClinicopathologic data of 247 patients with GIST from January 2003 to November 2012 in the Affiliated Hospital of Qingdao University Medical College, and the prognostic factors were evaluated retrospectively by univariate and multivariate analysis with Log-rank test and Cox proportional hazard model.

RESULTSPatients were followed up with a median time of 26 months (1 to 113 months). Twenty-six patients developed recurrence or metastasis, and 18 died of GIST. The 1-, 3-, 5-year survival rates were 94%, 91% and 83% respectively. Univariate analysis showed that age, tumor location, tumor size, mitotic count and tumor rupture were predictive factors of survival after resection of primary GIST (all P<0.01). For patients at intermediate and high risk to relapse, imatinib group had a higher 5-year overall survival rate than non-imatinib group (85.7% vs. 81.0%, P<0.05). Multivariate analysis revealed that tumor size (RR=2.248, 95%CI:1.081-4.677, P=0.030), mitotic count (RR=2.220, 95%CI:1.032-4.776, P=0.041) and tumor rupture (RR=5.183, 95%CI:1.677-16.017, P=0.004) were independent prognostic factors.

CONCLUSIONSTumor size, mitotic count and tumor rupture affect the prognosis after resection of primary GIST independently. Imatinib adjuvant therapy can improve overall survival of patients at intermediate and high risk to relapse after surgery.