Malignant gastrointestinal stromal tumors of the small intestine: a review of 50 cases from a prospective database.

BACKGROUND

Malignant gastrointestinal stromal tumors (M-GIST) are rare mesenchymal tumors originating in the wall of the gastrointestinal (GI) tract. Previous studies have included limited numbers of patients, and most included malignant and benign cases from throughout the GI tract. We reviewed the experience of a single tertiary cancer care center with M-GIST of the small intestine only.

METHODS

A prospective database identified all patients seen from 1989 to 1998. Clinical and pathological data, treatment, and outcome were analyzed. Overall median follow-up time was 24 months (range, 1-176 months).

RESULTS

Fifty patients (31 male, 19 female) were identified. Mean age at diagnosis was 55 years. Disease was localized in 11 patients, locally advanced (invasion into adjacent organs/peritoneum) in 24 patients, perforated in 4 patients, multiple primary lesions in 2 patients, and distant metastases in 9 patients. All patients underwent resection, which was complete in 70%. Locoregional recurrence (LR) developed in 43% (median, 25 months), and distant metastases in 59% (median, 21 months) of patients at risk. At last follow-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 with multiple primaries and distant metastases at diagnosis. Patients were grouped into three stages: (I) patients with localized and locally advanced disease; (II) patients with perforated; and (III) patients with multiple primaries and distant metastases. Actuarial OS at 5 years was 41% (n = 50)--42% for those with complete resection and 8% for incomplete resection. Univariable analysis showed that earlier stage at diagnosis (P = .001) and completeness of resection (P = .004) predicted for longer OS.

CONCLUSIONS

Most patients with M-GIST of the small intestine relapse following resection, but survival may be prolonged. In univariable analysis, stage at presentation and complete resection were significant prognostic variables for OS; grade was not significant. Localized and locally advanced M-GIST of the small intestine have a mean OS > 5 years. Complete resection should be the goal of initial surgical treatment.