Ch. 33 Colorectal Cancer PP Flashcards
most common histology type
adenocarcinoma
2nd most common histologic type
mucinous adenocarcinoma
histologic types with the worst prognosis
signet ring cell and squamous cell carcinoma
most common staging system for colorectal cancer
TNM
two most important prognostic indicators for survival
# of positive nodes depth of penetration through the bowel wall
classification according to the level of invasion into bowel wall and absence or presnece of positive nodes
Dukes staging
describe dukes A to C
A: not penetrated through bowel wall
B: penetrated through bowel wall, negative nodes
C: positive nodes
colorectal routes of spread
direct extension,
lymphatics,
blood, and
peritoneal seeding
most come site of blood borne distant spread
liver
second most common distant spread
lung
two most comes rectal cancer surgeries
low anterior resection
abdominoperineal resection
- removal of tumor plus a margin and immediately adjacent lyph nodes
- bowel reanastomsed, no colostomy
low anterior resection
- Performed if cancer located in lower 1/3 of rectum (distal 5cm)
- Requires a colostomy
- Rectum, anus, and draining lymphatics pulled out through perineal opening
- Requires a reconstruction of the pelvic floor using absorbable mesh, omentum or peritoneum
abdominoperineal resection
OAR when treating the pelvis
small bowel
OAR when treating ascending or descending colon
kidney