Recurrence Patterns and Clinical Behavior of Gastrointestinal Stromal Tumors (GISTs)

ABSTRACT

PURPOSE: Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasm of the gastrointestinal (GI) tract, and account for 1% of all GI malignancies. GISTs have a highly variable clinical course, and recurrent disease sometimes develops despite curative treatment. Although there are several known risk factors for recurrence, there are few adequate treatment strategies. This study evaluated the clinical behavior and clinicopathological characteristics, and examined correlation between recurrence and the prognostic factors. METHODS: From March 1999 to December 2005, 41 patients, with GISTs confirmed by a pathologic examination after a surgical resection, were enrolled. The patients were evaluated by immunohistochemical staining for CD117, CD34 and smooth muscle actin, and were classified according to the NIH criteria. RESULTS: The mean age was 58.9 years and the GISTs were mainly located in the stomach (56%) and small bowel (32%). With a median follow-up of 17.4 months, recurrence of the disease occurred in nine (22%) patients, with the liver being the main organ involved. According to the NIH criteria, there were 2 very low risk tumors, 11 low risk, 16 intermediate, and 12 high risk diagnosed. Gender was found to have predictive value for a recurrence (P=0.05). CONCLUSION: The primary site and gender have predictive value for a recurrence. Identifying the risk factors for recurrent disease may be useful for planning follow-up schedules. Further study involving more cases and a long-term follow-up will be needed. In addition, pathologic and immunohistoche-mical studies will be required to reduce the recurrence rate after a resection and to improve the patients' outcome.