Colorectal Cancer Flashcards

1
Q

The majority of colorectal cancers are what?

A

Adenocarcinoma (95%)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the risk factors for sporadic colorectal cancer?

A

Advanced age
Male
Previous adenoma/CRC
Environmental

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are the environmental risk factors for CRC?

A
Diet (low fibre, calc, high red meat)
Alcohol
Obesity
Low exercise
Smoking
DM
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are colorectal adenomas?

A

Colorectal polyps, usually benign

Tubular or villous

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What factors make colorectal adenomas high risk?

A

Size
Number
Degree of dysplasia
Villous architecture

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What actions cause an adenoma to become a carcinoma?

A

Activation of oncogenes
Loss of tumour suppressor genes
Defective DNA repair pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What oncogenes are involved in adenocarcinoma formation?

A

k-ras

c-myc

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What tumour suppressor genes are involved in adenocarcinoma formation?

A

APC
p53
DCC

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How does colorectal cancer present?

A
Rectal bleeding
Altered bowel habit
Iron deficiency anaemia
Palpable rectal/low right mass
Acute colonic obstruction 
Systemic symptoms
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What investigations would you give for a patient with suspected colorectal cancer?

A

Colonoscopy (therapeutic too)

CT abdo - barium enema

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How is colorectal cancer staged?

A

CT scan
MRI
PET/EUS

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

When is MRI used for staging of a colorectal tumour?

A

Rectal tumours

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What criteria is used for staging colorectal cancer?

A

TNM

Duke’s

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is Duke’s A criteria?

A

Confined to submucosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is Duke’s B criteria?

A

Invasion through muscularis without lymphatic involvement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is Duke’s C criteria?

A

Invasion through muscularis with regional lymph node involvement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What is Duke’s D criteria?

A

Presence of distant metastases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

How does the T staging work for colorectal cancer

A

T1 - confined to submucosa
T2 - Confined to muscularis
T3 - confined to serosa
T4 - breached serosa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How does the N staging work for colorectal cancer

A

N0 - no nodes involved
N1 - Up to 3 regional nodes
N2 - 4+ nodes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

How are most colorectal cancers treated?

A

Surgery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

When is colorectal cancer treated endoscopically?

A

Dukes A

Cancerous polyps

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How is chemotherapy used for colorectal cancer?

A

Dukes C, B
Adjuvant therapy
Micrometastases

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

How is radiotherapy used for colorectal cancer?

A

Rectal cancer only

Neoadjuvant +/- chemo

24
Q

What therapy is indicated for palliative care?

A

Chemotherapy

Stenting

25
Q

How can the prognosis of colorectal cancer be improved?

A

Prevention (lifestyle)

Screening

26
Q

What are the main forms of colorectal population screening?

A
Fecal occult blood test
Faecal immunochemical test
Flexible sigmoidoscopy
Colonoscopy
CT Colonography
27
Q

Who are the high risk groups for colorectal cancer?

A

Heritable conditions
Inflammatory bowel disease
Familial risk
Previous CRC

28
Q

What is FAP?

A

Familial adenomatous polyposis

29
Q

What type of genetic condition is FAP?

A

Autosomal dominant

30
Q

How does FAP affect the body?

A

50% adenomas in colon by 15yrs

95% by age 35yrs

31
Q

What causes FAP?

A

Mutation of APC on chromosome 5

32
Q

How are FAP patients treated?

A

Annual colonoscopy from age 10-12yrs (screening)

Prophylactic proctocolectomy

33
Q

Extracolonic manifestations of FAP

A

Duodenal adenomas

CHRPE (retinal epithelium hypertrophy)

34
Q

What is HNPCC?

A

Autosomal dominant mutation in DNA mismatch repair gene

Microsatellite instability

35
Q

How are HNPCC patients screened?

A

2 yearly colonoscopy

36
Q

What are HNPCC patients at risk of?

A

Early onset CRC (right sided)

Other, local cancers

37
Q

How is HNPCC diagnosed?

A

Bethesda genetic testing

38
Q

How are patients at high moderate risk due family history of CRC screened?

A

5 yearly colonoscopy from 50yrs

39
Q

How are patients at low moderate risk due family history of CRC screened?

A

One colonoscopy at 55 years

40
Q

How are IBD patients screened for colorectal cancer?

A

Colonoscopy 10 years post diagnosis

Dependent thereafter

41
Q

How are previous CRC patients screened for colorectal cancer?

A

5 yearly colonoscopy

42
Q

Which patients are considered high moderate risk of colorectal cancer?

A

CRC in 3 FDR, none <50

CRC in 2 FDR, mean age <60

43
Q

Which patients are considered low moderate risk of colorectal cancer?

A

CRC in 2 FDR >60yrs

CRC in 1 FDR <50yrs

44
Q

The majority of adenocarcinomas originate as what?

A

Adenomas - polyps

45
Q

Adenomas can take which shapes?

A

Pedunculated

Sessile

46
Q

What is the therapeutic benefit of colonoscopy?

A

You can find and remove any polyps

47
Q

How do you prepare a patient for colonoscopy?

A

Sedation

Bowel prep - laxatives

48
Q

When is CT colonography indicated in colorectal cancer?

A

When a patient is ineligible for colonoscopy

49
Q

When is CT abdo/pelvis indicated in colorectal cancer?

A

When patient cannot undergo bowel prep - only shows very large cancers

50
Q

What treatment is indicated for liver metastases?

A

Partial hepatectomy

51
Q

Rectal tumour treatment always result with what?

A

Colostomy

Neoadjuvant radiotherapy

52
Q

Which CRC patients get adjuvant chemotherapy?

A

Dukes C

- lymphatic spread

53
Q

What lifestyle changes can reduce risk of CRC?

A

30m exercise a day
Maintain healthy BMI
Eat 5 a day
Smoking cessation

54
Q

Who are screened for CRC, and how often?

A

50-74 year olds

FOBT every 2 years

55
Q

Why was FOB replaced with FIT?

A

FOBT has lower sensitivity in women

FIT is a more simple test

56
Q

Patients testing postive in FOBT are followed up how?

A

Colonoscopy

57
Q

HNPCC is associated with what cancers?

A

CRC (right colon)
Endometrial
Genitourinary