Microscopic margins of resection influence primary gastrointestinal stromal tumor survival.

Primary gastrointestinal stromal tumors (GISTs) are stromal tumors that arise from the gastrointestinal tract. Both surgical resection and molecular therapy are crucial in the treatment of these tumors. This study analyzes the outcomes of 151 patients with GIST treated at 3 institutions. These institutions comprise the GISTologist Study Group and provided follow-up data. PATIENTS AND METHODS: 151 patients with primary GIST were admitted and treated at the St. Orsola-Malpighi University Hospital in Bologna, Italy, the Catholic University Hospital in Rome, Italy, and the Modena University Hospital and National Cancer Institute in Naples, Italy, over the past 11 years. Patient data as well as tumor and therapy variables were studied to identify factors predicting survival with a focus on the microscopic margins of resection. RESULTS: All 151 patients had primary disease without metastasis and underwent complete resection of gross disease. The 5-year disease-free survival rate was 77%. Disease-free survival was predicted by tumor size, mitotic count, and margins of resection. Recurrence of disease after resection was predominantly intra-abdominal. CONCLUSIONS: Tumor size, mitotic count, and microscopic margins of resection predict disease-free survival in patients with primary GIST.