Microscopic margins of resection in gastrointestinal stromal tumor (GIST): An analysis of 122 patients

Abstract

10554 Background: The main treatment for localized GIST is complete surgical resection. The prognosis is strongly correlated with both tumor size and mitotic index. The aim of our study was to analyze retrospectively the outcome of patients affected by GIST related to microscopic margins of resection. Methods: The outcome of 122 patients surgically managed during the past 11 years, were evaluated. We analyzed the impact of R0 and R1 resection on DFS. Results: All patients but one, had a c-Kit positive GIST, 91% had primary disease without metastasis, 9% had metastasis. There were 46% high, 31% intermediate and 28% low risk GIST. The median age was 65 years (range 29–87). The most common sites of tumor origin were the stomach (54.9%) and the small bowel (36.9%). Sites of tumor metastasis were liver (18.2%), peritoneum (36.4%) or both (19.3%). R0 resection was achieved in 102 (83.6%) patients, while 16 pts (13.1%) had positive microscopic margins (R1). With a median follow up of 24 months (range 3–119), recurrence occurred in 34 (33.3%) R0 and in 9 (56.3%) R1 patients. The median DFS was 53.7 months and 35.6 months for the R0 and R1 group, respectively. The difference tested with univariate analysis using Long rank test, was not statistically significant (p= 0.228). Conclusions: In our series, the status of microscopic margins does not appear to be important for prediction of recurrence in patients affected by GIST. No significant financial relationships to disclose.