Gastrointestinal stromal tumors: a single institution experience of 50 cases.

ABSTRACT

BACKGROUND: Understanding the molecular pathogenesis of gastrointestinal stromal tumors (GIST) has led to targeted therapy using imatinib mesylate (IM). This retrospective series summarizes our short-term experience with 50 cases of GIST. METHODS: Case records of patients with GIST were analyzed. Tumor size, response to imatinib, and adverse events were evaluated every 3 months. RESULTS: The median age was 50 years (range 28-73). Stomach was the most common site (n=15). Thirty (60%) patients had complete resection of tumor with median progression free survival (PFS) of 12 months. The difference in PFS between intermediate and high risk groups was significant for patients who underwent resection (p=0.016). Thirty-five patients with advanced disease were administered IM 400 mg daily, and complete response was noted in 4 (11.8%); 13 (38.2%) each had partial response and stable disease, and 5 (14.8%) had progressive disease. Responses were not different in groups based on sex, site of primary tumor and number of metastatic sites. At a median follow up of 10 months, 72% patients continue to maintain response. CONCLUSIONS: This short-term study in patients with GIST describes response to therapy with imatinib in these patients.