Background: Primary adenocarcinoma of the small bowel is a rare neoplasm, and to the authors' knowledge, few studies to date have addressed the topic.
Methods: In the current study, the records of 217 patients with small bowel adenocarcinoma were reviewed retrospectively for the presentation, prognostic factors, treatment modalities, and outcome.
Results: The median age of the patients was 55 years and there were 133 (61%) males. Tumors originated in the duodenum in 113 (52%) patients, the jejunum in 54 (25%) patients, the ileum in 28 (13%) patients, and in nonspecified sites in 22 (10%) patients. Patients with proximal tumors were diagnosed for the most part using endoscopy (i.e., 46 of 108 [43%]), whereas laparotomy enabled diagnosis in 16 of 28 (57%) patients with distal tumors. Based on TNM staging, 9 (4%) patients had Stage I disease, 43 (20%) patients had Stage II disease, 86 (39%) patients had Stage III disease, and 75 (35%) patients had Stage IV disease. The liver was the most common site of metastasis in 44 (59%) patients. Cancer-directed surgery was performed in 146 (67 %) patients, including the Whipple procedure in 36 patients (17%). The median overall survival time was 20 months. The 5-year overall survival rate was 26%. Cancer-directed surgery, early-stage disease, and lymph node involvement ratio were significantly associated with overall survival by univariate analysis. However, only cancer-directed surgery and lymph node involvement ratio were independent predictors of overall survival in a multivariate analysis (adjusted rate ratio = 0.14; 95% confidence interval [95% CI], 0.04-0.46; P = 0.001 and adjusted rate ratio = 0.25; 95% CI, 0.12-0.53; P < 0.001, respectively).
Conclusions: Performing an oncologic surgery resulted in the best outcome in patients with nonmetastatic disease. Because cancer-directed surgery is associated with high morbidity and mortality in primary centers, these patients should be referred to a tertiary center for adequate treatment.