SCRT Followed by CAPOX + Bev ± PD-1 Inhibitor for TNT in LARC

This study aims to evaluate the efficacy and safety of short-course radiotherapy combined with CAPOX plus bevacizumab with or without a PD-1 inhibitor in patients with locally advanced rectal cancer (LARC). The hypothesis is that the addition of immunotherapy (PD-1 inhibitor) can significantly improve the complete response (CR) rate and enhance local control while reducing the incidence of distant metastasis. This study will compare the effects of sequential chemoradiotherapy and targeted therapy with or without immunotherapy following short-course radiotherapy, aiming to explore the optimal regimen for total neoadjuvant therapy.