Factors Impacting Neoadjuvant Treatment of GIST

Neoadjuvant therapy may be warranted in the management of gastrointestinal stromal tumors (GISTs), if the tumor will not be removed in its entirety, or with negative microscopic margins, or if there is a concern regarding overall response.

Imatinib, a tyrosine kinase inhibitor, is often used in a neoadjuvant setting to decrease tumor size and decrease vascularity, says Robert H. I. Andtbacka, MD. Decreasing tumor vascularity may decrease the risk of tumor rupture into the peritoneal cavity during surgery, explains Andtbacka. This neoadjuvant approach is often used in patients with esophageal, rectal, or large gastric GIST.

The duration of neoadjuvant therapy with imatinib depends on a team approach between the surgeon and medical oncologist, as well as evaluation of potential toxicities, notes Anthony P. Conley, MD. Toxicities associated with imatinib include peripheral edema, periorbital edema, cramping and fatigue. These events are generally tolerable, states Conley. Imatinib does not appear to cause bleeding or vascular complications, unlike other agents that target tyrosine kinase receptors.