Localized Small Bowel Adenocarcinoma Management: Evidence Summary

SIMPLE SUMMARY: Small bowel adenocarcinoma is a rare but aggressive disease that requires peri-operative treatment. Due to its rarity, there is little data on small bowel adenocarcinoma treatment, and most recommendations come from expert agreements or analogies to the management of colon cancer. In this Review, we summarize the current evidence on the management of localized small bowel adenocarcinoma, including future biomarker research perspectives that may help identify high-risk small bowel adenocarcinomas. ABSTRACT: Small bowel cancers are rare diseases whose prognosis is poorer than that of colon cancers. Due to disease rarity, there is little data on small bowel adenocarcinoma (SBA) treatment, and most recommendations come from expert agreements or analogies to the management of colon cancer. Although relatively high rates of local recurrence are observed for duodenal malignancies, distant metastatic relapse remains common and requires adjuvant systemic therapy. Given the similarities between SBA and colorectal cancer, radiotherapy and chemotherapy strategies used for the latter disease are frequently pursued for the former disease, specifically for tumors located in the duodenum. However, no previous randomized study has evaluated the benefit of adjuvant chemotherapy on the overall survival of SBA patients. Most previous studies on treatment outcomes and prognostic factors in this context were based on large international databases, such as the Surveillance, Epidemiology, and End Results or the National Cancer Database. Studies are required to establish and validate prognostic and predictive markers relevant in this context to inform the use of (neo) adjuvant treatment. Among those, deficient mismatch repair tumors represent 20% of SBAs, but their impact on chemosensitivity remains unknown. Herein, we summarize the current evidence on the management of localized SBA, including future perspectives.