Outcomes of patients with small intestine adenocarcinoma (SIA) in a Canadian province: A population-based cohort study.

Abstract

641 Background: SIA is a rare cancer. Limited data is available about clinicopathological factors and interventions that correlate with its outcomes. The current study aims to determine outcomes of patients with SIA who were diagnosed in a Canadian province. Methods: In this retrospective population-based cohort study patients with biopsy proven SIA diagnosed during 2008-2017 in the province of Saskatchewan were assessed. A Cox Proportional multivariate regression analysis was performed to determine correlation between survival and exploratory factors. Results: 112 eligible patients with median age of 73 yrs and M:W 53: 59 were identified. 75% had a comorbid illness, 34% had a secondary cancer and 45% had WHO performance status (PS) < 2. Of 112 patients, 51 (46%) had early-stage disease and 61 (54%) had advanced-stage disease. Median neutrophil: lymphocyte (NLR) was 4.5. The median overall survival (mOS) in relation to stage of the disease were as follow: stage 1, 59 months, stage 2, 30 months, stage 3, 20 months and stage 4, 3 months (P < 0.001). The patients with early-stage disease had mOS of 36.0 months (95% CI: 8.0-64.0) vs. 3.0 months (1.74-4.26) with advanced disease (P < 0.0001). Of 21 patients with stage 3 disease their median disease-free survival was 26 months (23.1-28.9) with chemotherapy vs. 4 months (0.0-9.1) with no chemotherapy, p = 0.04. Patients with stage 4 disease who had surgery and or chemotherapy had mOS of 18 months (13.70-23.32) vs. 4 months (2.20-5.82) with chemotherapy alone p = 0.03. On univariate analysis age ≥70 yrs, WHO PS > 1, stage 4 disease, low albumin, elevated creatinine, high alkaline phosphatase, duodenal cancer, lack of surgery, and NLR of > 4.50 were significantly correlated with inferior survival. On multivariate analysis stage 4 disease, HR, 3.20 (95%CI:1.84-5.40), WHO PS > 1, HR, 2.22 (1.42-3.45), no surgery, HR, 2.10 (1.25-3.50), and NLR > 4.5, HR, 1.72 (1.10-2.71) were significantly correlated with inferior survival. Conclusions: Most patients with SIA were diagnosed with advanced-stage. In addition to advanced-stage disease and poor PS, lack of surgery and baseline LNR of > 4.5 were significantly correlated with inferior survival.