Small Bowel Adenocarcinoma: 10-Year Experience in a Cancer Center-The Ottawa Hospital (TOH)

(1) Background: Small bowel adenocarcinoma (SBA) is one of the predominant primary small bowel cancers that has a dismal outcome. We aim to report 10 years of experience in SBA management at a regional cancer centre in Canada.; (2) Methods: We retrospectively analysed clinical and pathological data of patients diagnosed with an SBA between 2011 and 2021 at the Ottawa Hospital (TOH), Ottawa, Canada. We describe the clinicopathological features and outcomes, including survival. Potential prognostic factors were analysed using the Cox proportional hazard model for multivariate analysis.; (3) Results: We identified 115 patients with SBA. The duodenum was the most common SBA location representing 61% (70) of the total patients, followed by the jejunum (17%) and ileum (10%). Around 24% (27) of cases presented with bowel obstructions. The majority of patients (56%, 64) had stage IV disease on presentation. Seven patients had MSI-high tumours, while 24% (27) were MS-stable. In terms of management, 48 patients underwent curative surgical resection, 17 of whom received adjuvant chemotherapy. On the other hand, 57 patients (49.5%) with the advanced disease received palliative systemic therapy, and 18 patients (16%) had supportive care only. Over a median follow-up of 21.5 months (range 0-122), the median overall survival was 94, 61, and 34 months for stages II, III, and IV, respectively (p < 0.05). The median recurrence-free survival was 93 and 23 months for stages II and III, respectively. However, there was no statistically significant difference between TNM stages in RFS, p = 0.069. Multivariate Cox regression analysis showed only poor performance status at diagnosis as a predictor for shorter overall survival (p < 0.05). The univariate analysis didn't show any significant correlation between RFS and covariants.; (4) Conclusions: SBA remains one of the most aggressive tumours with a dismal prognosis even after surgical resection. The optimal chemotherapy regimen has not been established. Further studies are needed to explore the role of adjuvant chemotherapy for stages I-III SBA.