Imatinib Dosing in Gastrointestinal Stromal Tumors (GISTs): When, How Much, and How Long?

Imatinib therapy has revolutionized the treatment of patients with gastrointestinal stromal tumors (GISTs). Compared with older therapy, imatinib significantly improves outcomes in patients with metastatic disease and those with locally advanced tumors, raising progression-free and overall survival. Recent studies have evaluated variables such as timing of treatment, total dosing, and duration of therapy. Different genotypes are associated with a poorer response to imatinib therapy, whereas others may benefit from a higher starting dose. This review discusses recent data regarding optimal use of imatinib for treatment of GIST in both the adjuvant and metastatic settings, and addresses topics such as the impact of genotype on initial dose, dose escalation, optimal duration of treatment, and neoadjuvant therapy. Key ongoing clinical trials of imatinib in GIST are also discussed.