Colorectal Ca Flashcards
Polyps considered high risk when
> 1cm
Villous
Sessile
High grade dyplasia
Risk factors for colorectal Ca
Diet (High animal fat, low fibre)
Obesity (due to high insulin-> adenoma formation)
Low activity
Hereditory (FAP, HNPCC, MUYTH associated polyposis)
IBD
Gardener’s syndrome
Colonic polyps with extraintestinal manifestation
Polyposis + bain tumour
Turcot’s syndrome
Gold standard for diagnosisng colorectal Ca
Colonoscopy
Tests used to stage colorectal Ca
CXR US liver CT MRI pelvis PET scan
Resection used to remove tumours of upper rectum and lower rectum respectively
Anterior resection
Abdominoperineal resection
TNM staging for colorectal Ca
T0 no tumour Tis in situ T1 submucosa T2 muscularis propria T3 local T4 other organs
N0 no nodes
N1 one-three local nodes
N2 >4 nodes
M0 no mets
M1 mets
Staging of colorectal CA
Stage 1 - T1-T2
Stage 2 - T3-T4
Stage 3 - Nodes
Stage 4 - Mets
Stage 1 and 2 just suregry
Stage 3 adjuvant
Stage 4 palliation
Surgical factors that confer poor prognosis in colorectal Ca
· Tumour present at surgical margins · Obstructed tumour at presentation · Poorly differentiated tumour · Inadequate lymph node yield · Perineural invasion · Peritoneal deposits/micrometastases
Surveillance after colorectal Ca resection
CEA
Colonoscopy (6months, 1, 3, 5 years then every 5 years)
Tumours that FAPs are more at risk for
Periampullary CNS Thyroid Adrenl Hepatoblastoma Gastric Ca
Aetiology of large bowel obstruction
Colorectal Ca Volvulus Diverticular stricture Feacal impaction Forgeign body Hernia
Differential for large bowel obstruction
Small bowel obstruction Ileus Hirshsprung's disease Colonic pseudoobstruction Congenital leiomypoathy Toxic megacolon
