Which of the following treatment regimens is typically used for intermediate to high-risk GIST patients after tumor resection?

For intermediate to high-risk gastrointestinal stromal tumor (GIST) patients following tumor resection, the standard treatment regimen is to initiate adjuvant therapy with Gleevec, also known as imatinib. This treatment is pivotal because it targets the specific mutations that occur in GISTs, primarily affecting the c-KIT gene.

The rationale for using Gleevec in this setting stems from clinical trials indicating that adjuvant therapy can significantly reduce the risk of recurrence in patients at higher risk for metastasis or local progression after surgical removal of the tumor. Typically, a treatment duration of about one year is recommended based on evidence suggesting that this length of therapy is effective in improving long-term outcomes for these patients.

Other options such as observation, chemotherapy, or immediate reoperation do not align with current best practice guidelines for managing post-operative care in GIST patients. Observation alone lacks the necessary proactive approach to mitigate recurrence. Chemotherapy is generally ineffective for GISTs due to their unique biological behavior, and reoperation is not routinely performed unless there is evidence of residual disease or recurrence.