774PThe role of adjuvant therapy in resectable SBA: A different clinicians attitude with a relevant impact on outcome

Background: Small bowel adenocarcinoma (SBA) is a rare malignancy that accounts for 1-2% of gastrointestinal tumours. We evaluated the clinico-pathological characteristics, outcomes and prognostic factors of patients who underwent surgery for SBA. Methods: We retrospectively analysed the features and outcome parameters of 54 SBA patients from 6 italian institutions between 2005 and 2017. Results: The primary tumour was in the duodenum, jejunum and ileum in 30 (55.6%), 18 (33.3%) and 6 (11.1%) patients, respectively. Among the 54 patients studied, adjuvant chemotherapy were performed in 35.2 % of patients with stage II and in 27.8 % of patients with stage III. Relapse rates were higher for chemonaive patients compared to treated patients (50% vs 23.5%). Median overall (OS) and progression-free survival (PFS) were 26.98 and 19.78 months, respectively. Duodenal adenocarcinoma (p = 0.022), lymph node metastases (p = 0.00269), long-term treatment with metformin (p = 0.0095), no adjuvant treatment (p = 0.0006) and PLR >0,1766 (p = 0,0137) were associated with poor overall survival outcomes. The factors associated with PFS were patients with older age (>75 years) (p = 0.04) and T4 according to TNM system (p = 0.02). Conclusions: The lack of well-defined guidelines for treatment of SBA justifies the heterogeneity of therapeutic choices resulting in negative impact on patient outcomes. Thus, there is an urgent need for prognostic and predictive biomarkers to guide therapy decisions for these patients. Our results suggest that the site, lymph node metastases, metformin and PLR >0,1766 could be novel prognostic markers for SBA patients who undergo curative surgery. However, prospective studies are necessary to confirm the role of these factors and identify new potential biomarkers of treatment efficacy, that could improve the selection of the right treatment for the right patient. Legal entity responsible for the study: Modena University Hospital. Funding: Has not received any funding. Disclosure: All authors have declared no conflicts of interest.