Molecular response prediction in gastrointestinal stromal tumors

Gastrointestinal stromal tumors (GISTs) are rare tumors of mesenchymal origin that develop along the gastrointestinal tract. Over ten years ago, their management dramatically changed following the discovery of an activating mutation of the KIT oncogene, which led to the use of small molecule inhibitors to therapeutically target these mutant kinases. Patients with advanced GIST, who were once a subset of sarcoma with poor prognosis due to their lack of chemosensitivity, may now survive more than 5 years following treatment with tyrosine kinase inhibitors (TKI) such as imatinib mesylate (IM) and sunitinib malate (SU). After ten years of active clinical and preclinical research, it has become clear that, although relatively homogeneous compared to other solid malignancies, there is still some heterogeneity in GISTs and most notably in regard to response to therapy. Here, we review the current data regarding molecular prediction of response in this disease.