Therapeutic Strategies for Patients with Advanced Small Bowel Adenocarcinoma: Current Knowledge and Perspectives

Immunotherapy in small bowel adenocarcinoma: a potential role?

Small bowel adenocarcinoma (SBA) is a rare tumor with an unfavorable prognosis, and due to its rarity, few studies on its treatment are available. Chemotherapy remains the standard of treatment in advanced disease. Recently immunotherapy has demonstrated to be a valid therapeutic option for many solid tumors. We reviewed the data published in literature to understand the impact of immunotherapy in this cancer.

Adjuvant chemotherapy benefit according to T and N stage in small bowel adenocarcinoma: a large retrospective multicenter study

BACKGROUND

Small bowel adenocarcinoma is a rare cancer, and the role of adjuvant chemotherapy for localized disease is still debated.

METHODS

This retrospective multicenter study included all consecutive patients who underwent curative surgical resection for localized small bowel adenocarcinoma between 1996 and 2019 from 3 French cohort studies. Prognostic and predictive factors of adjuvant chemotherapy efficacy were analyzed for disease-free survival and overall survival. The inverse probability of treatment weighting method was applied in the Cox regression model using the propensity score derived from multivariable logistic regression.

RESULTS

A total of 354 patients were included: median age, 63.5 years; duodenum location, 53.5%; and tumor stage I, II, and III in 31 (8.7%), 144 (40.7%), and 179 (50.6%) patients, respectively. The adjuvant chemotherapy was administered in 0 (0%), 66 (48.5%), and 143 (80.3%) patients with stage I, II, and III, respectively (P < .0001). In the subgroup analysis by inverse probability of treatment weighting method, a statistically significant disease-free survival and overall survival benefit in favor of adjuvant chemotherapy was observed in high-risk stage II (T4 and/or <8 lymph nodes examined) and III (T4 and/or N2) but not for low-risk stage II (T3 and ≥8 lymph nodes examined) and III (T1-3/N1) tumors (Pinteraction < .05). Furthermore, tumor location in jejunum and ileum was also a statistically significant predictive factor of response to adjuvant chemotherapy in stage II and III tumors (Pinteraction < .05).

CONCLUSION

In localized small bowel adenocarcinoma, adjuvant chemotherapy seems to provide a statistically significant survival benefit for high-risk stage II and III tumors and for jejunum and ileum tumor locations.

Progress in the Treatment of Small Intestine Cancer

OPINION STATEMENT

Small intestine cancer is rare, accounting for approximately 3% of all gastrointestinal malignancies. The most common histological subtypes include adenocarcinoma, neuroendocrine tumours (NETs) and gastrointestinal stromal tumours (GISTs). In localised disease, surgery remains the mainstay of treatment and the best approach to improve survival. Current treatment for small intestine adenocarcinoma (SIA) is extrapolated from small studies and data from colorectal cancer (CRC). There is limited evidence to guide therapy in the adjuvant setting. However, there are small phase II studies in the advanced setting providing evidence for the role of chemotherapy and immunotherapy. There is also limited evidence assessing the efficacy of targeted therapies. Small intestine NETs are rare, with evidence for somatostatin analogue therapy, particularly in the low to intermediate-grade well-differentiated tumours. Poorly differentiated NETs are generally managed with chemotherapy but have worse outcomes compared with well-differentiated NETs. The management of small intestine GISTs is largely targeting KIT mutations with imatinib. Recent trials have provided evidence for effective therapies in imatinib-resistant tumours and the potential role of immunotherapy. The aim of this article was to review the evidence for the current management and recent advances in the management of small intestine adenocarcinoma, NETs and GISTs.

Clinical Outcome of Resected Non-Ampullary Duodenal Adenocarcinoma: A Single Center Experience

(1) Background: This study identified the clinical outcome and prognostic factors of resected non-ampullary duodenal adenocarcinoma (NADA) in a single tertiary cancer center. (2) Methods: The medical records of 109 patients with NADA who underwent curative surgery between 2000 and 2018 were reviewed retrospectively. (3) Results: The mean age was 62.4 years with a male predominance (70.6%). The majority of tumors were located at the 2nd portion (58.7%). Fifty-seven patients (52.3%) had symptoms at diagnosis. CA19-9 was elevated in 32 patients (29.4%). Of this cohort, most patients were diagnosed as stage III (64.2%). The median overall survival was 92.9 months, and the 1-, 3-, and 5-year survival rates were 84.4%, 71.6%, and 53.7%, respectively. In univariate and multivariate analysis, age, symptoms, CA19-9, and margin status were associated with overall survival and symptoms, CA19-9 and margin status were also associated with recurrence. When correlating symptoms with stages, patients with symptoms at diagnosis had more advanced stages (all p < 0.001). (4) Conclusion: Old age, elevated CA19-9, symptoms, and margin status were independent prognostic factors of NADA, and the patients with symptoms at diagnosis tend to have more advanced stages and a poor prognosis.

Potential biomarkers and immune characteristics of small bowel adenocarcinoma

Small bowel adenocarcinoma (SBA) is a gastrointestinal malignancy with low incidence but poor prognosis, and its pathogenesis is still unclear. This study aimed to explore potential disease-causing biomarkers of SBA. The gene expression datasets of SBA and normal samples were downloaded from the Gene Expression Omnibus database. First, differential gene expression analysis and weighted gene coexpression network analysis (WGCNA) were performed. Common genes (CGs) were obtained by intersection of differentially expressed genes (DEGs) and optimal modal genes of WGCNA. Subsequently, a protein‒protein interaction network was established to screen hub genes, and target genes were obtained by Lasso regression analysis of hub genes. An SBA risk prediction model was established based on target genes. The prediction accuracy of the model was evaluated by the area under the receiver operating characteristic curve (AUC). The levels of immune cell infiltration and activation of immune pathways were compared between SBA and normal samples using the "ggpubr" and "reshape2" packages. A total of 1058 DEGs were identified. WGCNA showed that the signature gene in the brown module was significantly associated with SBA (p = 7E−17), and 469 CGs were obtained. Four target genes (APOA4, APOB, COL1A2, FN1) were identified and showed excellent prediction of SBA risk (AUC = 0.965). In addition, active dendritic cells and macrophages showed higher infiltration levels in SBA. Meanwhile, the APC_co_stimulation pathway and parainflammation pathway were strongly active in SBA. Four target genes (APOA4, APOB, COL1A2, FN1) may be involved in the pathogenesis of small bowel adenocarcinoma.