Submucosa Carcinoma of the Rectum: Local Excision - pro Surgery

Submucosa Carcinoma of the Rectum: Local Excision pro Surgery Submucosa carcinomas of the rectum are defined as invasive carcinoma, infiltrating solely into the submucosal layer without infiltration of the muscularis propria (pT1). Compared to radical resection local treatment is especially beneficial regarding the quality of life (sphincter preservation, continence function) and postoperative complications. The risk of lymphatic metastases can be estimated by the depth of invasion into the submucosa (sm classification) as well as tumor grading and lymphatic invasion. It increases significantly with depth of invasion (sm1-sm3) and is significantly lower in low risk carcinomas (G1,2 without lymphatic invasion) compared to high risk carcinomas (G3,4 and/or lymphatic invasion). Local excision in curative intent is justified when the risk of postoperative mortality outweighs the risk of existing or remaining lymph node metastases. Standard polypectomy can be recommended in Haggitt 1-3 findings to be a save endoscopic procedure. In sm1a or sm1b carcinomas endoscopic mucosa resection is possible. Generally, these procedures have to be carried out with a save margin of clearance. In sm1b and sm2 tumors full-thickness local excision normally is indicated. It can be performed by transanal endoscopic microsurgery (TEM) as well as by transanal local full-thickness excision. It is justified as definite therapeutic procedure in curative intent, respecting the oncologic principles, in pT1 low risk carcinomas with a diameter up to 3 cm in curative (R0) resections. Only then, locoregional recurrence rates below 6% can be achieved. In high risk carcinomas radical resection is strictly recommended.