Characteristics and outcomes of small bowel adenocarcinoma: 14 years of experience at a single tertiary hospital in Saudi Arabia

Small bowel adenocarcinoma (SBA) is an extremely rare cancer type. In the present study, the patient characteristics and clinical outcomes of patients diagnosed and treated for SBA at a single tertiary hospital were reported. All patients diagnosed and managed between 2007 and 2020 were reviewed. Regression analysis was used to assess variables associated with the metastatic stage at diagnosis. The Kaplan-Meier method was used to estimate survival and the log-rank test was used to determine factors associated with survival outcomes. Out of 137 cases of small bowel primary tumor, 43 consecutive patients with SBA were diagnosed with a median age of 53 years and the majority (76.7%) were males. The common initial presenting symptoms were abdominal pain (58.8%) and bowel obstruction (30.2%). The most common primary site was the duodenum (60.5%) and the majority (65.1%) were diagnosed with stage III/IV disease. Patients with a high neutrophil-lymphocyte ratio (NLR) (≥0.85) were more likely to be in the metastatic stage at diagnosis (P=0.01). The 3-year overall survival (OS) rates based on stage were 100% (I), 85% (II), 53% (III) and 33.9% (IV) (P=0.001). In addition to the stage, the Eastern Cooperative Oncology Group Performance Status (P<0.001), NLR (P<0.001), hypoalbuminemia (P=0.02) and chemotherapy in a metastatic setting (P=0.02) were prognostic factors for OS. In conclusion, NLR is a potential prognostic biomarker for a metastatic stage at diagnosis. Advanced stage, lower performance status score, low albumin level and high NLR are associated with short OS.