[Treatment of extensive disease]

In locally advanced inoperable patients and metastatic patients imatinib is a standard treatment. Standard dose of imatinib is 400 mg daily. Treatment should be continued indefinitely, since treatment interruption is generally followed by relatively rapid tumor progression in virtually all patients. Dose intensity should be maintained by adequate management of side effects and a correct policy of dose reductions and interruptions in the case of excessive toxicity. The standard approach in the case of tumor progression is to increase the imatinib dose to 800 mg daily with special attention to the occurrence of side effects. Patient non-compliance should be ruled out as a possible cause of tumor progression as well as drug interactions with concomitant medications. In case of progression or intolerance to imatinib standard second-line treatment is sunitinib. The drug was approved effective in terms of progression-free survival according to a 4 weeks on and 2 weeks off regimen. Preliminary data show that a continuous regimen with lower daily dose may be equally effective but possibly better tolerated. After failing on sunitinib, the patient should be considered for participation in a clinical trial of new therapeutic agents or combinations such as tyrosine-kinase inhibitors (e.g., nilotinib), sorafenib, or inhibitors of the mTOR (mammalian target of rapamycin)-pathway.