Colorectal Carcinoma Flashcards
What age group presents most often with colorectal carcinoma?
Over 60s (86% of presentations)
Lost the factors that may predispose you to colorectal carcinoma?
Neoplastic polyps, IBD, genes (eg FAP 100% and HNPCC 60%), low fibre+red meat diet, high alcohol consumption, smoking, previous cancer
What measure can be taken to help prevent cancer development?
Taking aspirin 75mg daily reduces incidence and mortality by inhibiting polyp formation
How would left sided colorectal carcinoma present?
Bleeding/mucus PR, altered bowel habit, obstruction, tenesmus, PR mass, abdo mass, perforation, haemorrhage, fistula
How would a right sided colorectal carcinoma present?
Weight loss, decreased haemoglobin, abdo pain, abdo mass, perforation, haemorrhage, fistula.
What are the 2 week referral criteria for lower GI malignancy?
Over 40 with bleeding and bowel habit change
Any age with a palpable abdo mass that’s unlikely to be bowel
Palpable rectal mass
Men or non menstruating women with Hb below 11/10
Any individual with UC
What investigations would you do?
FBC, faecal occult blood, sigmoidoscopy, barium enema, CEA (carcinoembryonic antigen), LFTs, liver USS, CT/MRI, colonoscopy (gold standard)
Where is colorectal cancer most likely to spread to?
Liver, lung, brain
How does colorectal cancer spread?
Via local invasion, blood, lymph, transcoelomic
When would you do a right hemicolectomy?
For caecal, ascending and proximal transverse tumours
When would you do a left hemi-colectomy?
Distal transverse and descending tumours
What operation would you do for a sigmoid tumour?
A sigmoid colectomy
When would you do an anterior resection?
In low sigmoid tumours and high rectal tumours
When would you do the anastamosis?
At the end of the first operation
When would you do an abdominal-perineal resection?
In rectal cancer
What is the problem with an AP resection?
Requires a per enact colostomy as patient will be incontinent
If the bowel perforates what emergency surgical procedure is done?
Hartmann’s procedure
The patient is unfit for major surgery and has a rectal tumour, what procedure would you do?
Transanal endoscopic microsurgery via protoscope
What is the preferred method of conducting many of these procedures?
Laparoscopically
What palliative procedure is done to relieve symptoms of obstruction/bowel habit change?
Endoscopic stenting
When is radiotherapy used in colorectal cancer?
Mostly in palliative cases. (Sometimes pre-op rectal cancer or tumours with high recurrence rate)
Is chemotherapy used?
Yes, it is used adjuvantly (decreases mortality by 25% in dukes stage C)
What is the name of the chemotherapy regimen?
FOLFOX (folinic acid and oxaliplatin) (anti angiogenics may also be added)
What is the staging system used in colorectal cancer?
Dukes staging system
List the stages and their meaning…
A: limited to muscularis mucosae
B: extension through muscularis mucosae
C: involvement of regional lymph nodes
D: distant metastases
5 year survival for dukes stage A?
93%
5 year survival for dukes stage D?
6.6%
At what age to men get offered colorectal screenings?
60-75
How is colorectal screening done?
Faecal occult home testing kits
Where do most colorectal tumours develop?
Sigmoid colon and rectum
What gene mutation causes normal cells to become hyper proliferative?
APC gene mutation
Hyper proliferation leads to an early Adenocarcinoma, what mutation progresses it to an intermediate adenoma?
K ras mutation
What mutation leads to an intermediate adenoma devolving into a late adenoma?
DCC mutation
What mutation leads to the late adenoma finally becoming a carcinoma?
p53 tumour suppressor mutation
Oncogenes are dominant, true or false?
True
What type of cancer are the majority of colorectal carcinomas?
Adenocarcinoma
