原发性直肠癌仅行放疗可以基本根治,因而,辅以放疗可降低局部复发的危险。术前或术后放疗可阻止肿瘤细胞增殖并杀死未切除或脱落的肿瘤细胞,而同时化疗可以进一步增强杀灭肿瘤细胞或控制局部肿瘤复发的能力,还可清除微循环的转移。辅助治疗适用于肿瘤T3、T4期根治性切除术术前、术后和/或适用于肿瘤局部淋巴结转移。 Basic radiotherapy for primary rectal cancer can be radically treated. Therefore, supplemented with radiotherapy can reduce the risk of local recurrence. Preoperative or postoperative radiotherapy can prevent the proliferation of tumor cells and kill unremoved or shedding tumor cells. At the same time, chemotherapy can further enhance the ability to kill tumor cells or control local tumor recurrence, and can also remove microcirculation metastasis. Adjuvant treatment is suitable for tumor T3, T4 radical resection before surgery, postoperatively and/or for local lymph node metastasis.