Short-course Radiotherapy Followed by Sequential Chemotherapy With or Without PD-1 Monoclonal Antibody and Bevacizumab as Total Neoadjuvant Therapy in pMMR/MSS Locally Advanced Rectal Cancer （SPARK）

Short-course radiotherapy → PD-1 monoclonal antibody and bevacizumab combined with CAPOX regimen chemotherapy (4 cycles) → PD-1 monoclonal antibody combined with CAPOX regimen chemotherapy (2 cycles) → undergo surgery or watch-and-wait strategy within 2-4 weeks after the last dose of capecitabine.

Short-course radiotherapy → CAPOX regimen chemotherapy (6 cycles) → undergo surgery or watch-and-wait strategy within 2-4 weeks after the last dose of capecitabine.