Imatinib dose escalation versus sunitinib as a second-line treatment against advanced gastrointestinal stromal tumors: A nationwide population-based cohort study

Background: Although treatment with imatinib in advanced gastrointestinal stromal tumor (GIST) patients has led to significant clinical benefits, the disease will eventually progress due to imatinib resistance. Treatment options after failure of first-line imatinib include imatinib dose escalation or shifting to sunitinib. However, there is no large-scale study to compare the efficacy difference between these two treatment strategies or the role of surgery. Results: This study recruited 521 advanced GIST patients including 246, 125, and 150 placed in groups 1, 2, and 3, respectively. Groups 1 and 2 had significantly longer overall survival (OS) as compared with the group 3 (median 37.5 months versus 16.0 months; p < 0.0001). After adjusting for confounding variables, groups 1 and 2 had longer OS than group 3. A favorable survival trend was seen with surgery, although this benefit disappeared after adjusting for confounding factors. Materials and Methods: We conducted a nationwide population-based cohort study using data from the Taiwan National Health Insurance Research Database from July 2004 to December 2010. Advanced GIST patients who no longer responded to first-line imatinib were stratified into three groups: imatinib dose escalation (group 1); imatinib dose escalation and a shift to sunitinib (group 2); a direct shift to sunitinib (group 3). The therapeutic success of the three treatment regimens and the effect of surgery were evaluated by overall survival. Conclusions: For advanced GIST patients who failed first-line imatinib treatment, imatinib dose escalation confers significantly longer OS compared to a direct switch to sunitinib. Surgery does not provide survival benefits.