Clinicopathological features and treatment outcomes of metastatic or locally unresectable small bowel adenocarcinoma

Purpose: Small bowel adenocarcinoma (SBA) is an uncommon malignancy with poor prognosis and therefore difficult to study. The purpose of this study was to evaluate the characteristics, treatments and prognostic factors in patients with metastatic or locally unresectable SBA. Methods: Epidemiological and treatment data from metastatic or locally unresectable SBA patients who were admitted to Peking Union Medical College Hospital for first-line chemotherapy between December 2003 and November 2016 were retrospectively analyzed. Results: Of the 34 enrolled patients, 22 (64.7%) were male and 12 (35.3%) female, with a median age of 52 years. Tumors originated in the duodenum in 24 (70.6%) patients. All patients received one of the following regimens as first-line therapy: FOLFOX or XELOX (n=27), FOLFIRI or CAPIRI (n=5), GEMOX (n=1), and TP (n=1). The response rate and disease control rate were 11.8 and 61.8%, respectively. The median progression free survival (PFS) and overall survival (OS) were 4.5 and 13.8 months, respectively. Multivariate analysis revealed that liver metastasis was independently associated with poor PFS, and both unresected primary tumor and males were significantly associated with poor OS. The survival of three metastatic patients was 52-96 months after combination treatment of chemotherapy, resection of primary tumor and metastasis. Conclusions: The prognosis of metastatic or locally unresectable SBA was poor, and unresected primary tumor and males were significantly associated with poor OS. Combined modality therapy of systemic chemotherapy combined with local treatment of the primary tumor and oligometastasis might improve prognosis in selected patients.