Post-operative imatinib in patients with intermediate or high risk gastrointestinal stromal tumor

AimsThis study aims to determine whether adjuvant treatment with imatinib improves recurrence-free survival (RFS) in Chinese patients undergoing complete resection of localized primary gastrointestinal stromal tumor (GIST) compared with those not receiving adjuvant therapy. We also sought a correlation between c-KIT mutations and RFS.MethodsPatients who had undergone complete tumor resection with intermediate or high risk of recurrence were enrolled in a single-center, non-randomized, prospective study. Patients either received adjuvant imatinib therapy (400 mg once-daily) for 3 years or did not. Mutation analyses of c-KIT were performed on available archival tumor samples.Results105 patients were enrolled: 56 in the treatment group and 49 in the control group. Median follow-up was 45(43.1–46.9) months. RFS at 1, 2 and 3 years were higher in the treatment group than in the control group (100% vs. 90% at 1 year; 96% vs. 57% at 2 years; 89% versus 48% at 3 years, P < 0.001, HR = 0.188). Subgroup analyses showed that adjuvant therapy significantly decreased the risk of recurrence in patients whether at high risk or at intermediate risk compared with control patients (3-year RFS: 95% vs. 72%, in intermediate risk; 85% versus 31% in high risk; P < 0.001). In addition, imatinib adjuvant treatment decreased the risk of death (P = 0.039, HR = 0.254).ConclusionsAdjuvant imatinib can improve 1-, 2- and 3-year RFS rates in patients at intermediate or high risk of recurrence after complete tumor resection.Clinical Trials Registration Number: ChiCTR-TCC-00000582