직장암 수술 선택, Rectal cancer: surgical techniques(local excision, sphincter-sparing resection, APR)

아래 조건을 모두 만족하는  early rectal cancer에서는 local excision이 가능합니다.
*  Rectal cancer에서 T1은 muscularis propria에 진입하지 않은 submucosa까지 침범한 경우입니다.
▣Superficial T0 or T1 rectal cancer.
▣Tumor less than 3 cm in diameter.
▣Tumor involves <30 percent of the bowel lumen circumference.
▣Tumor is mobile and nonfixed.
▣Able to achieve clear margins with local excision.
▣Favorable histologic features based upon biopsy (ie, well- to moderately differentiated cancer, no lymphovascular or perineural invasion).
▣No radiographic evidence of metastatic disease to regional nodes (N0).
▣Patient compliant with aggressive postoperative surveillance.

Local excision 대상이 아닌 invasive rectal adenocarcinomas 환자에서는 radical transabdominal surgery를 시행합니다. Negative distal margin이 달성될 수 있다면 sphincter-sparing resection(partial 또는 total resection of the rectum(예, low anterior resection [LAR]) followed by a colorectal or coloanal anastomosis)를, 적절한 distal margin을 얻을 수 없다면 abdominal perineal resection(APR)를 시행합니다. 즉 cT2 이상은  sphincter-sparing resection(예, LAR) 또는 APR을 시행합니다. 

다음 기준을 모든 만족하는 rectal cancer는  sphincter-sparing resection을 시행해야 합니다. 
▣Invasive rectal cancer cT2-4.
▣A negative distal margin can be achieved. 
▣Adequate presurgical anorectal sphincter function.

다음 중의 하나라도 만족하는 invasive, cT2-4 rectal cancer는 APR을 시행해야 합니다.
▣A negative distal margin of 1 cm cannot be achieved with any of the sphincter-sparing procedures.
▣Locally advanced low-lying rectal cancer.
▣Locally recurrent low-lying rectal cancer (as a salvage procedure).
▣Poor presurgical anorectal function.

REF. UpToDate 2018.10.09