Study on Predictive Biomarkers of Neoadjuvant Chemoradiotherapy for Rectal Cancer

Backgrounds: A multicenter randomized phase III trial (NCT02605265) proved that adding irinotecan guided by UGT1A1 to capecitabine-based neoadjuvant chemoradiotherapy significantly increases complete tumor response. The treatment toxicities were increased but tolerable. Purposes: This study aims to identify the predictive biomarkers (from patients' tumor biopsy samples and peripheral blood samples before neoadjuvant therapy) for predicting the response and toxicities to neoadjuvant therapy to stratify patients and optimize treatment strategy.