Tytherleigh M G, Warren B F, Mortensen N J McC
Department of Colorectal Surgery, John Radcliffe Hospital, Oxford, UK.
Br J Surg. 2008 Apr;95(4):409-23. doi: 10.1002/bjs.6127.
Early rectal cancer (ERC) is adenocarcinoma that has invaded into, but not extended beyond, the submucosa of the rectum (that is a T1 tumour). Local excision is curative for low-risk ERCs but for high-risk cancers such management is controversial.
This review is based on published literature obtained by searching the PubMed and Cochrane databases, and the bibliographies of extracted articles.
ERC presents as a focus of malignancy within an adenoma, as a polyp, or as a small ulcerating adenocarcinoma. Preoperative staging relies on endorectal ultrasonography and magnetic resonance imaging. Pathological staging uses the Haggitt and Kikuchi classifications for adenocarcinoma in pedunculated and sessile polyps respectively. Lymph node metastases increase with the Kikuchi level, with a 1-3 per cent risk for submucosal layer (Sm) 1, 8 per cent for Sm2 and 23 per cent for Sm3 lesions. Low-risk ERCs may be treated endoscopically or by a transanal procedure. Transanal excision or transanal endoscopic microsurgery may be inadequate for high-risk ERCs and adjuvant chemoradiotherapy may be appropriate. There is a low rate of recurrence after local surgery for low-risk ERCs but this increases to up to 29 per cent for high-risk cancers.
早期直肠癌（ERC）是指侵犯直肠黏膜下层但未超出该层的腺癌（即T1期肿瘤）。局部切除对低风险ERC具有治愈性，但对于高风险癌症，这种治疗方法存在争议。
本综述基于通过检索PubMed和Cochrane数据库以及提取文章的参考文献获得的已发表文献。
ERC表现为腺瘤内的恶性病灶、息肉或小溃疡性腺癌。术前分期依赖于直肠内超声和磁共振成像。病理分期分别采用Haggitt和Kikuchi分类法对有蒂息肉和无蒂息肉中的腺癌进行分类。淋巴结转移率随Kikuchi分级升高而增加，黏膜下层（Sm）1级病变的转移风险为1% - 3%，Sm2级为8%，Sm3级为23%。低风险ERC可通过内镜或经肛门手术治疗。经肛门切除或经肛门内镜显微手术可能不适用于高风险ERC，辅助放化疗可能更为合适。低风险ERC局部手术后复发率较低，但高风险癌症的复发率可高达29%。
