We hypothesis that, regardless of the MSI state, immunotherapy combined with immediate chemotherapy after stenting may improve overall survival by eradicating micrometastasis. Moreover, immunotherapy (Camrelizumab, an anti-PD-1 antibody) combined with neoadjuvant chemotherapy prolongs the interval between stent placement and surgery, and the time for bowel decompression is more sufficient, which may increase the success rate of primary anastomosis and decrease risk of stoma formation, and furthermore, improve OS and PFS.