局部进展期直肠癌（LARC）是指肿瘤已侵及肠壁全层，可能波及邻近组织或淋巴结，但尚未发生远处转移。LARC的治疗目标在于减少局部复发，提升肛门保留率，并降低远处转移的风险。目前，LARC的标准治疗方案主要包括新辅助放化疗（nCRT）、全直肠系膜切除术（TME）以及辅助化疗。尽管nCRT和TME显著降低了局部复发率，但远处转移以及整体病理完全缓解率（pCR）偏低，依然是当前面临的主要挑战。近年来，免疫治疗，尤其是免疫检查点抑制剂（如PD-1/PD-L1抑制剂），在癌症治疗中展现出显著前景。研究表明，免疫治疗与nCRT联合应用，可显著提高pCR率和临床完全缓解率（cCR），并提升肛门保留率，尤其对单一免疫治疗不敏感的错配修复功能正常（pMMR）或者微卫星稳定型（MSS）患者效果尤为显著。本文将探讨新辅助放化疗联合免疫治疗在局部进展期直肠癌中的相关问题。

Locally advanced rectal cancer (LARC) is defined as a tumour that has invaded the entire bowel wall and may have spread to adjacent tissues or lymph nodes, but has not yet developed distant metastasis.The goals of treatment for LARC are to reduce local recurrence, improve anal retention, and reduce the risk of distant metastasis.Currently, the standard treatment options for LARC mainly include neoadjuvant radiotherapy (nCRT), total mesorectal excision (TME), and adjuvant chemotherapy.Although nCRT and TME have significantly reduced the rate of local recurrence, distant metastasis and low overall pathological complete remission (pCR) rates remain major challenges.In recent years, immunotherapy, especially immune checkpoint inhibitors (e.g., PD-1/PD-L1 inhibitors), has shown significant promise in cancer treatment.Studies have shown that the combination of immunotherapy and nCRT can significantly increase the pCR rate and clinical complete remission (cCR) rate, and enhance anal retention, especially for microsatellite-stabilised (MSS) patients who are usually insensitive to single immunotherapy.In this paper, we will discuss the issues related to neoadjuvant radiotherapy combined with immunotherapy in locally progressive rectal cancer.