Outcome after resection of one hundred gastrointestinal stromal tumors

To evaluate the outcome after surgical resection in patients with gastrointestinal stromal tumors and to determine the factors influencing local tumor recurrence or distant metastatic disease after locally complete tumor resection (R0).

Outcomes of 100 patients with primary gastrointestinal stromal tumors (GIST) surgically managed between 1997 and 2006 at a single institution were reviewed. Univariate and bivariate analyses were used to determine factors affecting recurrence-free and tumor-free survival.

All patients (n = 100) had c-kit-positive GIST. There were 17% (n = 17) very low risk, 41% (n = 41) low risk, 19% (n = 19) intermediate risk and 23% (n = 23) high risk GIST originating from the stomach, small bowel, colon and rectum. The median patient age was 68 years (range 39-92). Seventy-three percent of the patients had symptomatic local disease. Most (94%; n = 94) of them underwent R0 resections of their primary tumor. R0 resection was significantly associated with a lower tumor-related mortality rate (p = 0.0001). The patients with recurrence/metastases had significantly larger tumors (p = 0.0017) and a mitotic index higher than 5/50 HPF (p = 0.0001). Seven of 20 patients from the high-risk group and 2 of 7 patients with metastatic disease developed local recurrence or further metastatatic tumor spread following R0 resection.

Surgical removal continues to be the mainstay of GIST treatment. R0 resection, tumor size and mitotic index are significant prognostic factors. Overall, more than 30% of the patients with high-risk GIST develop local recurrences and distant metastases despite R0 resection. Additional molecular pathological markers are needed to yield a more accurate tumor profile and to thus achieve a better predictability of the biological behavior of GIST.