Colorectal cancer Flashcards
1
Q
Lifetime risk of developing CRC
A
- Risk is 5-6% 2. Age is the most important risk factor for sporadic CRC
2
Q
Etiology
A
- Genetic 2-3 X increased risk when family history in single first degree Further +if occurred at young age
- Environmental Obesity High energy intake ?Red meat
3
Q
Typical spread
A
- Lymph nodes
- Liver via venous
- Lung via hematogenously
- Bone
- Brain
4
Q
Risk factors
A
- Increasing age
- APC mutation
- Lynch syndrome
- MYH-associated polyposis
- Hamartomatous polyposis
- Inflammatory bowel disease
- Obesity ?Fibre, limited physical activity, acromegaly
5
Q
Classical Presentations
A
- Suspicious signs and symptoms
Abdominal pain
Change in bowel habit
Rectal bleeding
Anemia
Abdominal distension
Weight loss
- Asymptomatic with screening
- Emergency w/ obstruction, peritonitis, bleeding
6
Q
Anemia- more common sign for which side
A
Right
7
Q
Investigations
A
- FBC->anemia
- LFTs->normal unless liver mets
- Renal function, UEC->normal unless compression on ureters
- Colonoscopy->ulcerating exophytic mucosal lesion that may narrow bowel lumen
- Barium enema
- CT thorax, abdomen, pelvis, colonography
Others to consider
- Pelvic MRI
- TRUS
- Biopsy
- CEA
- PET
8
Q
Monitoring post treatment purposes
A
- Treatment related complications
- Recurrence at primary
- Metachronous
- Monitor for potentially resectable metastatic
- 3-6 monthly review for 2 years, then yearly for 5 years
9
Q
Complications of treatment
A
- bone marrow suppression during chemotherapy
- oxaliplatin-associated hepatotoxicity
- chemotherapy-associated GI (diarrhoea, nausea, vomiting, abdominal pain) 4. chemotherapy-associated alopecia
- cetuximab-associated rash
- radiotherapy-associated faecal incontinence
- bladder dysfunction after rectal excision
- erectile dysfunction after rectal excision
- oxaliplatin-associated pulmonary fibrosis
- oxaliplatin-associated neuropathy
10
Q
Prognosis
A
Overall, 5-year survival rates for colorectal cancer are 93% to
- 97% for stage I disease, 90%
- 72% to 85% for stage II disease, 70%
- 44% to 83% (depending on nodal involvement) for stage III disease, 50%
- 10%
11
Q
Screening guidelines for CRC
A
- Average risk: FOBT from 50 every 2years
- Moderately increased risk: colonoscopy/sigmoidoscopy 5 yearly from 50, or 10 years younger than age of first diagnosis
- High risk: refer for genetic screenin a) Lynch->1-2 yearly colonoscopy from 25/5 years younger whichever early. Aspirin 100mg / day b) FAP-> yearly from 12-15 to 30, then 3 yearly
12
Q
Define average risk
A
- Aged 50-75
- Asymptomatic
- No personal history
- 1 first degree/2nd w/ CRC >55 yo
13
Q
Define moderately increased risk
A
- One 1st degree <55
- Two first or one first + second on same side diagnosed at any age
14
Q
Define high risk
A
- Asymptomatic
- 3+ same side with suspected Lynch/other related
- 2 + same side w/ CRC and high risk features
Multiple in same individual
CRC <50
Family member with Lynch
- First degree with large number of adenomas (FAP)
- High risk mutation in APC/MMR
15
Q
Adenoma recurrent
A
- 25% after one polyp found
- 50% if multiple adenomas found
16
Q
Management and F/U for adenomas
A
- Colonoscopy w/ polypectomy
- >2 polyps/>1cm->yearly colonoscopies
- If clear->3-5 yearly