Malignant gastrointestinal stromal tumors of the small intestine: A reviewof 50 cases from a prospective database

Background: Malignant gastrointestinal stromal tumors (M-GIST) are rare mes enchymal tumors originating in the wall of the gastrointestinal (GI) tract. Previous studies have included Limited numbers of patients, and most inclu ded malignant and benign cases from throughout the GI tract. We reviewed th e experience of a single tertiary cancer care center with M-GIST of the sma ll intestine only. Methods: A prospective database identified all patients seen from 1989 to 1998. Clinical and pathological data, treatment, and outc ome were analyzed. Overall median follow-up time was 24 months (range, 1-17 6 months). Results: Fifty patients (31 male, 19 female) were identified. Mean age at d iagnosis was 55 years. Disease was localized in 11 patients, locally advanc ed (invasion into adjacent organs/peritoneum) in 24 patients, perforated in 4 patients, multiple primary lesions in 2, patients, and distant metastase s in 9 patients. All patients underwent resection, which was complete in 70 %. Locoregional recurrence (LR) developed in 43% (median, 25 months), and d istant metastases in 59% (median, 31 months) of patients at risk. At last f ollow-up, 14 patients were alive (6 disease-free), 2 had died disease-free, and 34 died with recurrent disease. Overall survival (OS) was similar for localized and locally advanced disease; OS also was similar for patients wi th multiple primaries and distant metastases at diagnosis. Patients were gr ouped into three stages: (I) patients with localized and locally advanced d isease; (II) patients with perforated; and ( III) patients with multiple pr imaries and distant metastases. Actuarial OS at 5 years was 41% (n = 50)-42 % for those with complete resection and 8% for incomplete resection. Univar iable analysis showed that earlier stage at diagnosis (P = .001) and comple teness of resection (P = .004) predicted for longer OS. Conclusions: Most patients with M-GIST of the small intestine relapse follo wing resection, but survival may be prolonged. In univariable analysis, sta ge at presentation and complete resection were significant prognostic varia bles for OS; grade was not significant. Localized and locally advanced M-GI ST of the small intestine have a mean OS > 5 years. Complete resection shou ld be the goal of initial surgical treatment.