PAEA Surgery End Of Rotation (EOR) Practice Exam

What is the medical therapy for GIST tumors?

1. Chemotherapy

2. Radiation therapy

3. Imatinib

4. Observation

The correct answer is: Imatinib

Gastrointestinal stromal tumors (GISTs) are often associated with mutations in the KIT or PDGFRA genes, which drive tumor growth. Imatinib, a targeted therapy and tyrosine kinase inhibitor, specifically inhibits the activity of the abnormally activated KIT protein, thereby blocking the signals that promote tumor cell proliferation and survival. This makes imatinib the primary medical therapy for patients with GISTs, particularly those with unresectable tumors, metastatic disease, or when surgery cannot be curatively performed. The use of imatinib has significantly improved the outcomes for patients with GISTs, reducing tumor size and symptom burden. It is important to monitor patients on imatinib therapy for side effects and disease response, often utilizing imaging studies to assess tumor changes over time. Other treatments such as chemotherapy and radiation therapy are generally not effective for GISTs due to their unique biology. Observation may be considered in specific clinical contexts, especially for small, asymptomatic tumors, but it is not considered a primary medical therapy for GISTs when there is a risk of progression or metastasis. Therefore, imatinib is the standard and most effective medical therapy for managing these tumors.