Colorectal Cancer Flashcards
How do most colorectal cancers arise and what is the most common type?
From polyps to form adenocarcinomas
What part of the GI track does colorectal cancer affect?
rectum and sigmoid colon are the most common
Give some risk factors for developing colorectal cancer
Age >65 Genetic syndromes (FAP, HNPCC/Lynch) IBD High fat/meat diet Polyposis syndrome Obesity, smoking, alcohol Nullparity/Late pregnancy
Where does colorectal cancer metastasise?
Firstly to liver - 25% present with liver mets
Can go to lung, brain and bone
How do right sided colorectal cancers present?
Weight loss
Anaemia
RIF mass
Occult bleeding
How do left sided colorectal cancers present?
Colicky pain Rectal bleeding Change in bowel habit Tenesmus LIF mass Bowel Obstruction
What signs would suggest advanced colorectal cancer?
Hepatomegaly
Jaundice
How would you go about investigating ?colorectal cancer
FBC - anaemia
CEA
Faecal occult blood test
LFTs - mets
What imaging is used to investigate colorectal cancer
Contrast CT staging
Colonoscopy or CT colonography
MRI of mesorectum if tumour below peritoneal reflection
Elderly/ major comorbidities: Flexi sig + barium enema
Describe what each of the T stages in TNM stages means in relation to colorectal cancer
T1 - invade submucosa
T2 - invade muscularis propria
T3 - Invade pericolic tissues
T4 - perforate visceral peritoneum
When do GP’s trigger the 2 week wait referral for colorectal cancer?
> 40 with WL and abdo pain
50 with rectal bleeding
60 with iron deficiency anaemia or change in bowel habit
When is chemotherapy used in colorectal cancer?
Advanced and metastatic disease
Those with high risk of disease recurrence
When is a right hemicolectomy performed? What is done during the procedure?
Any ascending colon tumours
Part or all of ascending colon and cecum removed. Colon anastomosed to small intestine (ileo-colic)
When is a left hemicolectomy performed? What is done during the procedure?
Any descending colon tumours
Part or all of descending colon removed. Transverse colon anastomosed to rectum (colo-colic)
When is a sigmoid colectomy performed? What is done during the procedure?
Tumours affecting the sigmoid colon
Part/all of sigmoid colon removed. Descending colon connected to rectum (colo-rectal)
When is an anterior resection performed? What is done during the procedure?
High anterior resection: sigmoid tumours
Anterior resection: rectal tumours
sigmoid colon and portion of rectum removed. Colorectal anastomosis formed
+TME (removal of mesorectal fat and lymph)
When is an abdo-perineal resection performed? What is done during the procedure?
Lower rectal tumours and any tumour involving the sphincter
removes the anus, rectum, and sigmoid colon. No anastomosis
Where does a HNPCC colon cancer normally affect?
What other cancers is HNPCC associated with?
Proximal colon
Endometrial
What is the current colorectal screening programme?
Every 2 years
Age 60-74
FOBT
What are some complications of colorectal cancer surgical management?
Anastomotic leak, adhesions, hernia
Stoma complications:
- parastomal hernia, ischaemia/necrosis, obstruction, skin irritation, prolapse, retraction leading to a poor bag seal
What is Hartmanns’ procedure?
Resection of sigmoid colon, closure of the anorectal stump and formation of end colostomy
What are the advantages and disadvantages of parenteral nutrition?
little patient effort
sepsis
catheter obstruction
thrombosis
refeeding syndrome
What are the advantages and disadvantages of enteral nutrition?
low cost
maintains gut
few infection risks
aspiration risk
tube displacement
gastric distention
risk of malnutrition
