Adenocarcinoma of the small bowel: a study of 37 cases with emphasis on histologic prognostic factors

Abstract

Purpose: Primary small-bowel adenocarcinoma is uncommon. There are few large studies that have evaluated the prognostic impact of clinical and pathologic parameters. The purpose of this study was to perform a comprehensive analysis of the Cleveland Clinic experience with small-bowel adenocarcinoma, with emphasis on histopathologic parameters as prognostic indicators.

Methods: Thirty-seven cases of primary small-bowel adenocarcinomas resected at the Cleveland Clinic between 1978 and 1999 were retrospectively studied. Metastatic tumors and those arising from the biliary system were excluded from analysis. Clinical and pathologic data were recorded and their impact on prognosis was evaluated by either Kaplan-Meier or Cox proportional hazards analysis.

Results: The cohort included 25 males, and the age range was 24 to 82 (mean, 56) years. Tumor location was duodenum (18), jejunum (10), ileum (2), and site not specified (7). Patients most frequently presented with abdominal pain (48 percent), anemia (39 percent) and small-bowel obstruction (33 percent). Underlying conditions included Crohn's disease (4) and familial adenomatous polyposis (2). Overall survival was 52 and 47 percent at 5 and 10 years, respectively, with a mean follow-up of 50.5 (range, 0.5-184) months for all patients. Features found to be negative prognostic factors for survival were positive surgical margins (P < 0.001), extramural venous spread (P < 0.001), lymph node metastases (P = 0.038), poor tumor differentiation (P = 0.015), depth of tumor invasion (P = 0.023), and history of Crohn's disease (P < 0.001). Age, gender, tumor size, growth pattern, lymphocytic host response, and adjuvant therapy did not affect survival.

Conclusions: Pathologic features, including positive surgical margins, extramural venous spread, positive lymph nodes, poor tumor differentiation, depth of tumor invasion, and history of Crohn's disease, are of major prognostic significance in small-bowel adenocarcinoma. Although many of these prognostic features are similar to the ones used for colorectal adenocarcinoma, they are easily applicable and reproducible for small-bowel adenocarcinomas. This is important considering the often dismal prognosis of small-bowel adenocarcinoma.