Colorectal Cancer Flashcards Preview

07. Year 2: Alimentary System > Colorectal Cancer > Flashcards

Flashcards in Colorectal Cancer Deck (74)
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1

What cause of cancer death is colorectal cancer?

2nd leading

2

What overall cause of cancer is colorectal cancer?

3rd

3

What is the most common histological classification of colorectal cancer?

Adenocarcinoma (95%)

4

What percentage of colorectal cancer is colonic and what is rectal?

2/3 is colonic

1/3 is rectal

5

What genes are associated with colorectal cancer?

HNPCC (5%)

FAP (<1%)

Other CRP syndromes

6

What are risk factors for sporadic cases of colorectal cancer?

Age

Male gender

Previous adenoma

Environmental influences (diet, obesity, lack of exercise, smoking, diabetes)

7

What kind of things in your diet are risk factors for colorectal cancer?

Low fibre

Low fruit and veg

Low calcium

High red meat

High alcohol

8

What percentage of colorectal cancers have no genetic influence?

85%

9

What do majority of colorectal cancers arise from?

Pre-existing polyps

10

What are polyps?

Protuberant growths

11

What are the different kinds of polyps?

Epithelial or mesenchymal

Benign or malignant

12

What is an adenoma?

Benign tumour of glandular tissue

13

What is an adenoma in origin?

Epithelial

14

What are the different histological types of adenoma?

Tubular (75%)

Indeterminate tubulovillous (15%)

Villous (10%)

15

Explain the adenoma-carcinoma sequence?

Activation of oncogene, loss of tumour suppresor gene and defective DNA repair pathway genes (microsatelite instability) cause adenoma to become carcinoma by causing cell growth proliferation apoptosis

16

What are examples of oncogenes?

K-ras

C-myc

17

What is an oncogene?

A gene that has the potential to cause cancer

18

What are examples of tumour suppressor genes?

APC

p53

DCC

19

What are tumour suppresor genes?

Ones that control cell growth

20

What is the presentation of colorectal cancer?

Rectal bleeding (especially if mixed in with stool)

Altered bowel opening to loose stools (longer than 4 weeks)

Palpable rectal or right lower abdominal mass

Acute chronic obstruction if stenosing tumour

Weight loss

Anorexia

21

What investigations are done for colorectal cancer?

Colonoscopy

Radiological imaging

22

What is the investigation of choice for colorectal cancer?

Colonoscopy

23

What can be done with a colonoscopy?

Tissue biopsy

24

What does a colonoscopy require?

Sedation

Bowel preparation

25

What are risks of a colonoscopy?

Perforation

Bleeding

26

What radiological imaging is done for colorectal cancer?

CT colonography

Barium enema

27

What investigations are done to stage colorectal cancer?

CT scan of chest/abdomen/pelvis

MRI scan for rectal tumours

PET scan/rectal endoscopic ultrasound in selected cases

28

For Duke's staging, what is T1 to T4?

T1 - confined to submucosa

T2 - confined to muscularis

T3 - confined to serosa

T4 - breached serosa, invading other structures

 

29

For Duke's staging, what is N0 to N2?

N0 - no lymph node involvement

N1 - seen in 3 regional lymph nodes

N2 - seen in 4+ regional lymph nodes

30

For Duke's staging, what is M0 to M1?

M0 - no metastases to distinct organs

M1 - metastasis to distinct organs