GI - Colorectal Carcinoma: Ix, Mx And Prevention

Question 1

Ix: bloods and imaging

Answer 1

• Bloods: FBC (Hb), LFTs (mets), tumour marker (CEA - carcinoembryonic antigen)
• Imaging: CXR (lung mets), US liver (mets), CT and MRI (staging - MRI best for rectal Ca and liver mets), Endoanal US (staging rectal tumours), BA/gastrograffin enema (apple-core lesion)

Question 2

Ix: endoscopy/biopsy

Answer 2

• Flexi sig: 65% of tumours are accessible

- Colonoscopy

Question 3

Name and explain a non TNM staging system for colorectal carcinoma

Answer 3

-Dukes 
A) Confined to bowel wall (90% 5ya survival)
B) Through wall but no lymph nodes (60)
C) Regional lymph nodes (30)
D) Distant mets (<10)

Question 4

Give the stages of TNM

Answer 4

• T(is): carcinoma in situ
• T1: submucosa
• T2: muscularis propria
• T3: subserosa
• T4: through serosa to adjacent organs
• N1: 1-3 nodes
• N2: >4 modes
• M: present or no?

Question 5

Mx: pre surgical

Answer 5

• Manage in MDT
• Confirmation of Dx
• Stage with CT or MRI (chest, abdo and pelvis)
• 60% amenable to radical surgery

Question 6

Principals of surgery

Answer 6

• Excision depends on lymphatic drainage which follows arterial supply
• Remove entire part of bowel supplied by blood vessels that supply tumour
• Hartmann’s often used if obstruction is present
• laparoscopic approach is standard of care

Question 7

Tumour location and recommended procedure/area resected

Answer 7

• Rectal (depends on distance from anal verge - if >4-5 cm do defunctioning loop ileostomy/primary anastomosis OR if <4cm do permanent end colostomy)
• Sigmoid: high anterior resection or sigmoid colectomy
• Left: left hemicolectomy
• Transverse: extended right hemicolectomy
• Caecal/right: right hemicolectomy

Question 8

Other Rx available

Answer 8

• local excision
• bypass surgery: palliative
• hepatic resection: if single lobe mets only
• stenting: palliative or bridge to surgery in obstruction
• Chemo

Question 9

NHS screening for CRC- FOB testing

Answer 9

• Introduced in 2006
• 60-76years
• Home FOB testing kit every 2 years: 1/50 have +ve FOB
• Colonoscopy if +vs: 1/10 have Ca

Question 10

NHS screening for CRC: flexi sig

Answer 10

• Introduced in 2011/2012
• 55-60ya
• Once only flexi sig