Colorectal cancer Flashcards
1
Q
Staging of colorectal cancer
- Stage 1/A
- Stage 2/B
- Stage 3/C
- Stage 4/D
A
- Stage 1/A - confined to bowel wall, 90% remission
- Stage 2/B - through bowel wall, 50% remission
- Stage 3/C - involves regional lymph nodes
- Stage 4/D - metastatic, 50% remission with chemotherapy, radiotherapy and surgery
2
Q
Risk factors for colorectal cancer
A
A DWARFISM SHOP
Age
Diabetes Western diet Alcohol Radiation exposure Family history IBD Smoking Male sex
Sedentary lifestyle
Hereditary defects (Lynch syndrome, FAP)
Obesity
PHx cancer or polyps
3
Q
Vogelstein’s adenoma-carcinoma sequence
A
p53 and APC genes
4
Q
Consequences of loss-of-function mutations in:
- APC
- p53
- BAX
A
- APC - increased cell signalling via the Wnt signalling pathway
- p53 - decreased tumour suppression
- BAX - decreased tumour suppression
5
Q
Most common type of tumour in colorectal cancer
A
Adenocarcinoma (98%)
Others - lymphoma, SCC
6
Q
Macroscopic pathology of right vs. left sided cancers
A
Right-sided - exophytic
Left-sided - circumferential
7
Q
Cell morphology of colorectal cancer
A
- Irregular tubular structures, may secrete mucus
- Multiple lumens
- Reduced stroma
- Signet-ring cells
8
Q
Symptoms of colorectal cancer (9)
A
- PR bleeding (68%)
- Altered bowel habit (59%)
- Weight loss
- Fatigue
- Loss of appetite
- Nausea/vomiting
- Anaemia (R)
- Worsening constipation (L)
- Decrease in stool calibre (L)
- Tenesmus (L)
9
Q
Management of colorectal cancer, including follow-up guidelines
A
- Preoperative chemoradiation
- Preoperative radiotherapy (long course, 25 fractions) - for large rectal tumours
- Laparoscopic resection (90%)
Follow-up
- 3 monthly for 2 years (CEA)
- 6 monthly for 2-5 years (CEA)
- CT and colonoscopy after 1 year
- Reduce energy and fat, increase vegetables and fibre
10
Q
Perforation risk of colonoscopy
A
1 in 1000
11
Q
Overall 5 year survival rate
A
65%
