Surgical treatment for rectal cancer: An international perspective on what the medical gastroenterologist needs to know

Table 1 Vocabulary for rectal cancer treatment

	Treatment
Anterior resection	Resection of rectum with an anastomosis above the pelvic peritoneal reflection.
Low anterior resection	Resection of rectum with an anastomosis below the pelvic peritoneal reflection.
TME	Total mesorectal excision. The fatty tissue which contains the draining lymph nodes surrounding the lateral and posterior part of the rectal tube, are dissected down to the pelvic floor and resected. The hypogastric nerves are preserved.
PME	Partial mesorectal excision. The mesorectum is divided 5 cm below the cancer and rectum transected. PME is performed for cancers located in the upper rectum and rectosigmoid junction.
TEM	Transanal endoscopic microsurgery. A specially constructed proctoscope with an attached microscope permits local resection of premalignant lesions and selected cases of early rectal cancer up to 20 cm from the anal verge.
TAE	Transanal excision. Lesions in the lower third of rectum can be resected transanally.
APR	Abdominoperineal resection. Low rectal cancers that cannot be resected with a sphincter-saving procedure are resected with perianal tissue and the anal channel en block with the whole rectum and mesorectum.
Adjuvant	Additional treatment (chemotherapy, radiation therapy or chemoradiation) given after surgical resection.
Neoadjuvant	Preoperative treatment.
CRT	Chemoradiation treatment. Chemotherapeutic drugs, typically 5’-fluorouracil and/or leucovorin are given in order to increase cancer cells sensitivity to the radiation. CRT is frequently offered to patients preoperatively (neoadjuvant) in order to reduce the chances for local recurrence and improve survival.
Intersphincteric resection	The upper part of the internal anal sphincter muscle is resected continuously with the lower rectum in order to preserve anal function and avoid colostomy in cases of ultralow rectal cancer.
CRM	Circumferential resection margin is the distance in mm from the mesorectal fascia (the resection plane) to the nearest tumor growth.
DRM	Distal resection margin.