Small bowel sarcoma: analysis of survival from the National Cancer Data Base

Small bowel sarcomas (SBS) are rare, accounting for 10% of small bowel cancers. As a result, few studies of SBS have had enough patients to accurately define their natural history and to determine the factors that have an impact on patient survival. The objective of this study was to examine patient and tumor factors in SBS and to determine prognostic factors for disease-specific survival (DSS) using the National Cancer Data Base.

Data from the National Cancer Data Base for patients diagnosed with primary SBS between 1985 and 1995 were analyzed. The chi2 statistic was used to determine significant differences between groups of patient, tumor, and treatment factors. DSS was calculated for patients diagnosed between 1985 and 1990. Significant differences in survival were determined using the Wilcoxon statistic for univariate analyses and by Cox regression in multivariate analyses.

Of 14,253 small bowel tumors diagnosed between 1985 and 1995, sarcomas represented 10.1%. Overall, 5-year DSS was 38.9%, with a median survival of 34.1 months (n = 590). By univariate analysis, patient age, sex, tumor size, tumor grade, histologic type, general summary stage, nodal status, and whether cancer-directed surgery was performed were significantly correlated with DSS. In multivariate analysis, tumor size <5 cm, leiomyosarcoma histology, and localized disease were found to be significant favorable prognostic factors for DSS.

SBS are rare tumors that are challenging in terms of their histopathologic classification, grading, and staging. Patients with SBS were treated predominantly by surgery, with a minority receiving adjuvant therapy. Tumor size, histologic type, and general summary stage were independent prognostic factors for 5-year DSS in patients with SBS, which is improved relative to 5-year DSS seen in patients with small bowel adenocarcinoma.