Perforation of the Colon During Imatinib Mesylate (Gleevec) Treatment in a Patient with Chronic Myeloid Leukemia (CML)

Imatinib (Gleevec; STI-571) is a tyrosine-kinase inhibitor (TKI) used in the treatment of multiple cancers, most notably Philadelphia chromosome-positive (Ph+) chronic myelogenous leukemia (CML) as well as gastrointestinal stromal tumor (GIST). The most common adverse effects with imatinib include superficial edema, muscle cramps, musculoskeletal pain, rash, fatigue, headache, and gastrointestinal side effects. Less frequent side effects include pancytopenia, febrile neutropenia, flushing, and liver function test abnormalities. Very rare side effects include secondary malignancies, Sweet's syndrome, angioedema, or cardiac arrest. We report the first case report of gastrointestinal perforation complicating imatinib treatment for CML. Unlike other antiangiogenic TKIs such as sunitinib or sorafenib that target vascular endothelial growth factor (VEGF) and known to cause gastrointestinal perforation, imatininib is a TKI with no known anti-VEGF activity, and so it remains unclear how imatinib would be associated with developing this life threatening complication. However, physicians caring for patients of imatinib should be aware of this potential toxicity. We suggest that careful attention and an appropriate clinical evaluation are required for patients presenting with gastrointestinal symptoms during imatinib treatment.