Gastrointestinal stromal tumor (GIST) -- single center experience of prolonged treatment with imatinib.

ABSTRACT

BACKGROUND: The tyrosine kinase inhibitor imatinib has been introduced into the treatment of gastrointestinal stromal tumors (GIST). Here we report our results of prolonged treatment in comparison to a similar group of GIST patients who had died before imatinib became available. METHODS: Fourteen patients with recurrent or metastatic GIST were treated with imatinib. Clinical data and tumor samples of ten patients from the pre-imatinib era were available for comparison. Comparative genomic hybridisation (CGH) was performed on tumors to identify changes that may predict response to treatment. RESULTS: Fourteen patients were treated, mean treatment time 22.3 months (1 non-response, 2 progression after initial response, 2 stable diseases, 8 partial responses, 1 complete response). Adverse side effects were mild in general. Survival was higher in the treated group (41.1 months vs. 34.8 months in the historical group). Eleven treated patients are alive. CGH analysis showed comparable numbers of chromosomal aberations in both groups. CONCLUSION: Prolonged treatment with imatinib is safe and effective in patients with recurrent or metastatic GIST.