Management of early rectal cancer

Abstract

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.