Clinical Effect Of Imatinib On Gastrointestinal Stromal Tumors

Objective: To evaluate the clinical effect and adverse effect of imatinib on unresectable/recurrent/metastatic gastrointestinal stromal tumors (GISTs) or as neoadjuvant/post-operative adjuvant therapy. Methods: 80 patients with GISTs were confirmed by pathologic and immunohistological examination. All of these GISTs expressed CD117. Patients were administered imatinib 400mg/d. Fifty-seven patients were classified to unresectable/recurrent/metastatic group, 20 patients were post-operative adjuvant group, 3 patients were neoadjuvant group. Clinical effect and adverse effect were evaluated through regular examination.Result: All patients were follow-uped. In unresectable/recurrent/metastatic group, 45 patients were treated with imatinib immediately after tumor was found to be unresectable/recurrent/metastatic. With a median follow-up of 15 months, no patients was evaluated CR, 19 patients was evaluated PR (42.2%), 19 was evaluated SD (42.2%), 7 was evaluated PD (15.6%). Thirty-eight patients (84.4%) were acquired clinical benefit (disease control). One-year and 2-year progression-free survival (PFS) were 88.9% and 86.7%. One-year and 2-year overall survival (OS) were 100% and 95.6%. Twelve patients were treated with imatinib after palliative resection of unresectable tumor or resection of recurrent/metastatic tumor. With a median follow-up of 10 months, 11 patients were free of recurrence or metastasis, 1 patient recurred 1.5 months after resection (1 month after imatinib administration) and died. One-year recurrence-free survival rate (RFS) and OS both were 91.7%. Twenty patients were treated as post-operative adjuvant therapy. With a median follow-up of 8 months, all patients were free of tumor. One-year RFS was 100%. Three patients were treated as neoadjuvant therapy. Successful resections were conducted after imatinib administration for 4～7 months when 1 patient was evaluated SD and 2 were PR. Adverse effects were mild and toleratable mostly. Conclusion: Imatinib shows beneficial effects on GISTs with only mild and toleratable adverse effects.