Imatinib mesylate therapy in advanced gastrointestinal stromal tumors—A Regional cancer centre experience

Abstract

19505 Background: The treatment of gastrointestinal stromal tumors has been revolutionised by the advent of Imatinib, a specific tyrosine kinase inhibitor. Post operative local and metastatic recurrences of this tumor have been effectively managed by Imatinib. Here we present our experience of Imatinib in recurrent locally advanced/metastatic gastrointestinal stromal tumors (GIST). Methods: From Nov 2001 to Sep 2005, 33 patients with metastatic and / or locally advanced inoperable CD-117 positive GIST were offered imatinib mesylate therapy at 400 mg/day p.o. A total of 21 patients were evaluable for tumor response. Follow up period ranged from 4 months to 38 months with median follow up period being 18 months. Median age is 58 yrs, M:F ratio is 6:4. ECOG performance status was 0–1 in 70% (23 patients) and 2 in 30% (10 patients). 70% patients had post surgery recurrence. 2 patients (6%) had received adjuvant chemotherapy prior to recurrence. 30% (10 patients) had local recurrence, 40% (13 patients) had metastatic disease while 30% (10 patients) had local recurrence as well as metastatic disease. Results: Response evaluation was done by RECIST criteria. 15% (5 patient) showed CR while PR rates were 30% (10 patients). The overall major response (CR+PR) was 45%. The overall progression free survival was as high as 80%. All the patients who had a progression free survival also had a significant improvement in quality of life. Conclusions: Imatinib mesylate therapy shows significant survival benefits in locally advanced inoperable/metatstatic gastrointestinal stromal tumors. It will be a very long time before PET scan for evaluation and follow up becomes feasible in developing country setting. No significant financial relationships to disclose.