OBJECTIVETo evaluate the efficacy and safety of imatinib mesylate in the treatment of patients as preoperative supplement, or used alone for unresectable and(or) metastatic gastrointestinal stromal tumor (GIST).

METHODSA total of 30 cases with advanced GIST were proved pathologically. Among them, CD117 was detected positive in 29 patients; 2 patients received imatinib mesylate before operation and 28 patients with unresectable and(or) metastatic GIST received oral imatinib mesylate daily at dose of 200-600 mg. Three patients were lost in follow-up and the objective effect was evaluated in 25 patients.

RESULTSFifteen of 25 patients (60.0%) achieved partial response (PR); 5 (20.0%) had stable disease (SD) and 5 (20.0%) had progression disease (PD). Median time to progression (mTTP) was more than 13 months during which most experienced benefit. Twenty-two patients had been followed-up more then 1 year. The 1-year survival rate was 86.4%. The overall median survival has not been obtained to date. Twenty-seven patients were valuable for the toxicity assessment according to the WHO standard. The main toxicity included grade I-II edema of periorbital area and lower limb in 85.2% (23/27) patients, leukopenia was present in 40.7% (11/27) and intratumoral bleeding in 7.4% (2/27). Other toxicities included mild fatigue (29.6%), abdominal pain (14.8%), efflorescence (11.1%), nausea and vomiting (18.5%).

CONCLUSIONAs an inhibitor of tyrosine kinase, imatinib mesylate is generally well tolerated and has been proved to be effective and safe during prolonged treatment of patients with advanced gastrointestinal stromal tumors.